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Hazard Control Plan Resources

Use these resources to help create your Hazard Control Plan (HCP).

Every HCP requires its own unique set of instructions. Adhering to the HCP can significantly reduce the risk of possible injury. The following resources will help you create HCPs when working with hazardous chemicals.

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Acutely toxic materials

Requirement for researchers

UC San Diego researchers working with acutely toxic materials must follow the acutely toxic materials hazard control plan (HCP) in the Chemical Hazard Use Application (CHUA).

This HCP must be preapproved by the principal investigator prior to beginning any work with this material. Information on this Blink page is supplementary and is not intended to replace the approved HCP.

Definition

An acutely toxic material is that which has been identified as causing acute health effects or long term chronic health effects. It has the potential to cause death, disability, or immediate damage to target organs as a result of a single exposure or an exposure of short duration, even at very low concentrations. These materials are categorized based on their LC50 or LD50 values and may also be characterized as toxic gases, select agent toxins, corrosives, irritants or sensitizers.

LD50 is the median lethal dose of a chemical administered orally causing death in 50% of test animals. It should be recognized that the minimum dose causing death in some proportion of the test population will be much lower, with significant illness or harm short of lethality probably occurring at even lower doses.

LC50 is the median lethal concentration of a chemical in air administered by continuous inhalation causing death to 50% of test animals.

The following table denotes the OSHA-defined toxicity designations, for various routes of exposures. Find the LD50 on a Safety Data Sheet (SDS) or in the Registry of Toxic Effects of Chemical Substances (RTECS) (http://www.cdc.gov/niosh/docs/97-119/). Compare the LD50/LC50 to the table to determine if it is acutely toxic.

OSHA Hazard Designation

Oral LD50 (rats, mg/kg)

Skin Contact LD50* (rabbits, mg/kg)

Inhalation LC50* (rats, ppm for 1 hr)

Highly toxic

<50

<200

<2000 ppm

On GHS-compliant Safety Data Sheets (SDSs), acutely toxic materials can be identified via the following hazard statements:

  • H300: Fatal if swallowed
  • H301: Toxic if swallowed
  • H310: Fatal in contact with skin
  • H311: Toxic in contact with skin
  • H330: Fatal if inhaled
  • H331: Toxic if inhaled

Acutely toxic material listings

Use the listings below to find out if your chemical inventory includes acutely toxic materials:

  • The lists above serve as guides and are not all inclusive. Review the Safety Data Sheet for other materials not listed.

Resources

References

Autoclave

Requirement for researchers

UC San Diego researchers working with an autoclave must complete an autoclave Hazard Control Plan (HCP) obtained through the Chemical Hazard Use Application (CHUA).

This HCP must be preapproved by the principal investigator prior to beginning any work with this material. Information on this Blink page is supplementary and is not intended to replace the approved HCP.

Definition

An autoclave is a device that uses water, pressure and heat to create superheated steam to kill infectious agents and denature proteins. They are also used to decontaminate certain biological waste and sterilize media, instruments and labware. They use saturated steam under pressure of approximately 15 pounds per square inch to achieve a chamber temperature of at least 250° Fahrenheit (121° Celsius) for a prescribed time – usually 30-60 minutes. When used properly, an autoclave is safe and highly effective. 

Autoclave Hazards

Autoclaves use high-pressure and high-temperature steam for sterilization; despite built-in safeguards, autoclaves present potential safety risks for operators that include:

  • Heat burns from hot materials and autoclave chamber walls and door.
  • Steam burns from residual steam coming out from autoclave and materials on completion of cycle.
  • Hot fluid scalds from boiling liquids and spillage in autoclave.
  • Hand and arm injuries when closing the door.
  • Cuts or lacerations from handling broken glassware.
  • Body injury if there is an explosion.
  • Infections from failed decontamination.
  • Slips, trips and falls from wet floors.

Special Requirements

  • All autoclave users must receive formal instruction on proper and safe use of the autoclaves. Contact your Safety Division Office, an experienced autoclave user in your lab, Scott Asbach for the Division of Biological Sciences, or a Research Assistance Program Contact in EH&S for training.
  • You must fill out the autoclave user log; Facilities Maintenance relies on user logs for autoclave maintenance and repairs.
  • Never set the autoclave temperature above 250° Fahrenheit (121° Celsius).
  • Never autoclave biological waste unless the autoclave is specifically designated as such and part of your lab’s Biohazard Use Authorization (BUA).
  • Report autoclave problems/malfunctions to Facilities Maintenance right away: 534-2930.             
    • Post a note on the broken autoclave to inform other users that a service call has been placed.
    • Always remove your items promptly after your cycle is finished.
    • If something breaks or spills, it is your responsibility to clean it up.
    • When in doubt, please ask. Better to ask than to injure yourself or damage the equipment.

Resources

References

Arsine

Requirement for researchers

UC San Diego researchers working with arsine must complete an Arsine hazard control plan (HCP) obtained through the Chemical Hazard Use Application (CHUA).

This HCP must be preapproved by the principal investigator prior to beginning any work with this material. Information on this Blink page is supplementary and is not intended to replace the approved HCP.

Note: The Arsine HCP must be used in conjunction with the Pyrophorics HCP.

Definition

Arsine is a colorless, flammable, pyrophoric, and highly toxic gas. It has a garlic-like or fishy odor that can be detected at concentrations of 0.5ppm and above. Because arsine is nonirritating and produces no immediate symptoms, persons exposed to hazardous levels may be unaware of its presence. Exposure frequently occurs when arsine gas is generated while metals or crude ores containing arsenic impurities are treated with acid.

Special Requirements

  • Consult with the UCSD Chemical Hygiene Officer before ordering arsine to ensure that you have met the requirements of the UCSD Compressed Gas Policy. There are significant fire code restrictions on the quantities of pyrophoric and highly toxic gases allowed in use or storage within research buildings. Failure to do this may lead to premature disposal of the material or costly building modifications.
  • Must be SCBA trained to change out gas cylinders and the UCSD Chemical Hygiene Officer must be notified prior to cylinder change-out.

Lessons Learned

Resources

References

Bromine

Requirement for researchers

UC San Diego researchers working with bromine must complete a bromine hazard control plan (HCP) obtained through the Chemical Hazard Use Application (CHUA).

This HCP must be preapproved by the principal investigator prior to beginning any work with this material. Information on this Blink page is supplementary and is not intended to replace the approved HCP.

Definition

Elemental bromine, a non-combustible, dense, mobile, slightly transparent reddish-brown liquid, evaporates easily at a standard temperature and pressure — which gives off an orange vapor (its color resembles nitrogen dioxide) and a strongly disagreeable smell (similar to chlorine). Odor can be detected at concentrations as low as 0.05 ppm. It is 1 of only 2 elements on the periodic table that are known to be liquids at room temperature (mercury is the other). Being less reactive than chlorine but more reactive than iodine, bromine reacts vigorously with metals, especially in the presence of water, to give bromide salts. It is also reactive towards most organic compounds, especially upon illumination conditions that favor the disassociation of the diatomic molecule into bromine radicals. It bonds easily with many elements and has a strong bleaching action.

Bromine is highly corrosive to skin and eyes, causing irritation and destruction with blister formation. If it is not removed from the skin immediately, deep-seated ulcers develop, which heal slowly. Severely painful and destructive eye burns may result from contact with either liquid or concentrated vapors of bromine. It is toxic via inhalation, causing lacrimation at concentrations below 1 ppm. Higher concentrations cause irritation and damage to the respiratory tract, and eventually pulmonary edema and/or death. Symptoms include coughing, tightness of chest, nosebleed, headache and dizziness, follow after some hours by abdominal pain, diarrhea and a measles-like rash on the trunk and extremities.

Compatibility Notes

  • Bromine reacts violently with easily oxidized substances, including many organic compounds and a number of metals. Fires and explosions have been reported to occur, for example, on addition of bromine to methanol, acetaldehyde, dimethylformamide, hydrogen, ammonia, aluminum, mercury, sodium, potassium and phosphorous.

Lessons Learned

Resources

References

Carcinogens

Requirement for researchers

UC San Diego researchers working with carcinogens must follow the carcinogens hazard control plan (HCP) in the Chemical Hazard Use Application (CHUA).

This HCP must be preapproved by the principal investigator prior to beginning any work with this material. Information on this Blink page is supplementary and is not intended to replace the approved HCP.

Definition

A select carcinogen is defined in the Laboratory Standard as a substance that meets any of the following criteria:

  • It is regulated by California OSHA as a carcinogen; or
  • It is listed under the category, “known to be carcinogens,” in the Annual Report on Carcinogens published by the National Toxicology Program (NTP)(U.S. DHHS, 1991); or
  • It is listed under Group 1 (“carcinogenic to humans”) by the International Agency for Research on Cancer Monographs (IARC) (Volumes 1-48 and Supplements 1-8);
  • It is listed in either Group 2A or 2B by IARC or under the category, “reasonably anticipated to be carcinogens” by NTP, and causes statistically significant tumor incidence in experimental animals in accordance with any of the following criteria:
    • (a) after inhalation exposure of 6 to 7 h per day, 5 days per week, for a significant portion of a lifetime to dosages of less than 10 mg/m3;
    • (b) after repeated skin application of less than 300 mg/kg of body weight per week; or
    • (c) after oral dosages of less than 50 mg/kg of body weight per day.

Carcinogen listings

Use the listings below to find out if your chemical inventory includes known or suspected carcinogens.

NOTE:  If any work involves any of the listed carcinogenic materials in Title 8 of the California Code of Regulations, Section 5209, you must consult with the Chemical Hygiene Officer prior to purchase. These materials have stringent requirements which need careful evaluation before acquiring. If these regulatory requirements cannot be achieved then this material cannot be purchased.

53-96-3 2

ACETYLAMINOFLUORENE

92-67-1

4-AMINODIPHENYL

36341-27-2

BENZIDINE ACETATE

531-85-1

BENZIDINE DIHYDROCHLORIDE

14414-68-7

BENZIDINE HYDROCHLORIDE

21136-70-9, 531-86-2

BENZIDINE SULFATE

92-87-5

BENZIDINE (AND ITS SALTS)

612-83-9

3,3'-DICHLORBENZIDINE DIHYDROCHLORIDE

64969-34-2

3,3'-DICHLORBENZIDINE DIHYDROGEN BIS(SULFATE)

74332-73-3

3,3'-DICHLORBENZIDINE SULFATE

91-94-1

3,3'-DICHLORBENZIDINE (AND ITS SALTS)

60-11-7

4-DIMETHYLAMINOAZOBENZENE

134-32-7

1,-NAPHTHYLAMINE

91-59-8

2,-NAPHTHYLAMINE

92-93-3

4-NITROBIPHENYL

62-75-9

N-NITROSODIMETHYLAMINE

57-57-8

Beta-PROPIOLACTONE

542-88-1

BIS-CHLOROMETHYL ETHER

107-30-2

CHLOROMETHYL METHYL ETHER

151-56-4

ETHYLENEIMINE


Resources

References

Centrifuge

Requirement for researchers

UC San Diego researchers working with a centrifuge must follow the centrifuge hazard control plan (HCP) in the Chemical Hazard Use Application (CHUA).

This HCP must be preapproved by the principal investigator prior to beginning any work with this material. Information on this Blink page is supplementary and is not intended to replace the approved HCP.

Definition

A centrifuge is an important tool in a research lab, but can also be a dangerous instrument if not used or maintained properly. It is usually driven by an electric motor that puts an object in rotation around a fixed axis applying a potentially strong outward force. Low speed centrifuges that do not exceed 5,000 rpm are commonly found on bench tops. High speed centrifuges that do not exceed 25,000 rpm are generally floor models. Ultracentrifuges operate in excess of 100, 000 rpm.

Centrifuge Use Hazards

Serious hazards associated with centrifuging include mechanical failure and the creation of aerosols:

  • Mechanical failure (e.g., rotor failure, tube, or bucket failure) can cause serious damage to equipment, laboratory space, and worker injury.
  • High-speed rotor heads are prone to metal fatigue. Failure to discard rotors after a predetermined amount of use can result in dangerous and expensive rotor disintegration. Avoiding rotor failure is critically important!
  • Aerosols may be created when filling centrifuge tubes, removing plugs or caps from tubes after centrifugation, removing supernatant, resuspending sedimented pellets, and by the very process of centrifugation. The greatest hazard is created if a tube breaks during centrifugation.

Lessons learned

Resources

References

Flame sterilization

Requirement for Researchers

UC San Diego researchers working with flame sterilization must follow the flame sterilization hazard control plan (HCP) in the Chemical Hazard Use Application (CHUA).

This HCP must be preapproved by the principal investigator prior to beginning any work with this material. Information on this Blink page is supplementary and is not intended to replace the approved HCP.

Definition

Flame sterilization is done to inoculating loops and straight-wires in order to kill, deactivate, or eliminate all forms of life and other biological agents.

Precautions for Safe Handling

  • Clear area surrounding Bunsen burner of any combustible or flammable materials/chemicals before lighting the burner, including any bench liners or paper pads.
    • If your laboratory performs flame sterilization frequently, it is strongly recommended that you define a dedicated work space for these activities.
    • Always know where the safety equipment is (fire extinguisher, fire blanket, telephone, etc).
  • Use the minimum amount of solvent needed for the sterilization.
    • The volume may not exceed 100 ml to qualify for the Chemical Safety and Surveillance Committee exemption to the LHAT PPE requirements.
  • Position flammable chemicals required for the procedure away from the burner.
  • Gently start the gas flow and light the burner.
  • Do not wave utensil being sterilized in the air when using a flammable solvent (e.g. ethanol)
  • Never leave a flame unattended.
  • Ensure gas is shut off when finished with task.

Note: The use of plumbed natural gas and open flame burners within a biosafety cabinet (BSC) are strictly forbidden. See Biological Safety Cabinets: Open Flames and Flammable Gas Policy.

Alternatives

  • Consider alternative flame-less methods of sterilization:
    • Glass Bead Sterilizer
    • Infrared Micro-Sterilizer
    • Electric Bunsen Burner
    • Reusable polypropylene spreaders
    • Sterile disposable loops

Learn more about alternatives to continuous flame Bunsen burners.

Lessons learned

A recent lab fire due to flame sterilization use occurred when a researcher accidently dropped a flamed coverslip dipped in ethanol onto a benchtop. The coverslip was then knocked into an adjacent trashcan which resulted in a fire. Quick thinking and knowing where the lab’s fire extinguisher prevented the incident from escalating into something bigger!

It is prudent to set aside an area specific for flame sterilization that is clear from immediate and neighboring combustible materials. Always ensure that the solvent container is secure and that a fire extinguisher is nearby.

Additional flame sterilization incidents: 

Resources

Flammable Class 1

Requirement for researchers

UC San Diego researchers working with flammable liquids must complete a flammable Class 1 Hazard Control Clan (HCP) obtained through the Chemical Hazard Use Application (CHUA).

This HCP must be preapproved by the principal investigator prior to beginning any work with this material. Information on this Blink page is supplementary and is not intended to replace the approved HCP.

Definition

Flammable liquids have a flash point below 100° Fahrenheit (38° Celsius) regardless of the boiling point. This HCP also applies to liquids that are combustible or noncombustible (flash point at or above 100° F). Flammable solids are covered by the Pyrophorics HCP.

  1. Flammable and combustible liquids ignite easily and burn with extreme rapidity.
  2. Flammability is determined by the flash point of a material.
  3. Flash point is the minimum temperature at which a liquid forms a vapor above its surface in sufficient concentration that it can be ignited.
  4. Flammable liquids have a flash point less than 100° F. Liquids with lower flash points ignite easier.
  5. The vapor burns, not the liquid itself. The rate at which a liquid produces flammable vapors depends upon its vapor pressure.
  6. The vaporization rate increases as the temperature increases; therefore, flammable and combustible liquids are more hazardous at elevated temperatures than at room temperature.
  7. Consider substituting less flammable solvents where possible. For example, consider replacing pentane by heptane, consider finding an alternative to carbon disulfide if at possible.

Special Requirements

  • Flammable and combustible liquids present a danger of personal injury and property damage, so strict storage requirements are both essential and required by the law.
    • See Flammable and Combustible Liquids Overview for more details.
    • Always wear a flammable-resistant (FR) lab coat when handling quantities in excess of 1L.
    • Know where your lab’s fire extinguisher is located and how to use it.
      • See Fire Extinguisher Training for more information.
      • Keep only small quantities of flammable materials available for immediate use.
      • Flammable liquid containers, both dispensing and receiving vessel, must be bonded and grounded when transferring liquids.
        • See Bonding and Grounding for requirements and examples.
        • Transfer flammable and combustible liquids within a chemical fume hood when possible, or in a proper dispensing location such as a high hazard room (also called a flammable room).
        • Always store flammable liquids in a flammable cabinet when not in use.
          • Use only flammable rated refrigerators (spark-proof) if flammable liquids must be chilled or frozen.
          • Never use environment rooms (also called cold/warm rooms) to store flammable materials. Environmental rooms have many ignition sources and little or no outside air circulation.

Safety Information/Lessons Learned

Resources

Flash chromatography

Requirement for researchers

UC San Diego researchers working with flash chromatography must follow the flash chromatography hazard control plan (HCP) in the Chemical Hazard Use Application (CHUA).

This HCP must be preapproved by the principal investigator prior to beginning any work with this material. Information on this Blink page is supplementary and is not intended to replace the approved HCP.

Note: Depending on the chemicals used in flash chromatography this HCP must be cross referenced with other applicable HCPs. Examples: Flammable Class I HCP (methanol) and Carcinogens (methylene chloride).

Definition

Flash chromatography is a rapid form of preparative column chromatography for the separation or purification of compounds.

Flash Chromatography Hazards

  • Explosions
  • Flammable liquids
  • Pressurized vessels
  • Carcinogens
  • Toxics

Lab personnel must review the UC San Diego video "Flash Chromatography 101" prior to performing your first run: 

Resources

Gel electrophoresis

Requirement for researchers

UC San Diego researchers working with carcinogens must follow the gel electrophoresis hazard control plan (HCP) in the Chemical Hazard Use Application (CHUA).

This HCP must be preapproved by the principal investigator prior to beginning any work with this material. Information on this Blink page is supplementary and is not intended to replace the approved HCP.

Note that if the following chemicals are used in the gel electrophoresis process they require that the Acutely Toxic Materials HCP  be used in conjunction with the Gel Electrophoresis HCP:

  • Ethidium Bromide
  • Acrylamide

Definition

Gel electrophoresis is a method for separation and analysis of macromolecules (DNA, RNA and proteins) and their fragments, based on their size and charge. There are differing types of electrophoresis units but horizontal electrophoresis is the most commonly used unit for separating DNA molecules on agarose gels, which is a non-toxic polysaccharide derivative of agar. Vertical electrophoresis is used with a polyacrylamide gel medium, which is created from acrylamide and bis-acrylamide powder.

Evaluate the hazards

  • Chemical and reproductive hazards:
    • Acrylamide (suspected carcinogen, reproductive toxin and neurotoxin)
    • Ethidium bromide (possible mutagen and requires appropriate disposal)
    • Molecule staining agents (methylene blue, silver stain, Coomassie Brilliant Blue)
    • Flammable solvents
    • Thermal hazards:
      • Liquefying gels can produce superheated liquids
  • Radiological hazards:
    • UV light boxes
  • Electrical shock:
    • Potential hazardous current of up to 2000 volts and 80 milliamps
    • Handling conductive liquids around electricity

Injury prevention

  • Avoid handling chemical powders; purchase premixed solutions or pre-made gels instead of making them.
  • Use less hazardous and environmentally friendly alternatives to ethidium bromide such as GelRed, GelGreen (Biotium),SYBR Green and EZ Vision DNA Dye.
  • Never mix ethidium bromide into the buffer solution prior to heating it in the microwave.
  • Always let superheated liquids cool before handling and use insulated gloves.
  • Always inspect the electrophoresis unit and power supply for damage, missing parts, exposed connectors, leaks and liquid spills prior to use.

Resources

References

Glove boxes & anaerobic chambers

Requirement for researchers

UC San Diego researchers working with a glove box or anaerobic chamber must follow the glove box hazard control plan (HCP) in the Chemical Hazard Use Application (CHUA).

This HCP must be preapproved by the principal investigator prior to beginning any work with the equipment. Information on this page is supplementary and is not intended to replace the approved HCP.

Note: Depending on the chemicals used in a glove box or anaerobic chamber this HCP must be cross referenced with other applicable HCPs. Examples: compressed gases and pyrophorics.

Definition

Glove boxes, glove bags, and anaerobic chambers are equipment used for applications involving hazardous materials and/or manipulating substances that require a controlled atmosphere or vacuum. Some materials or processes may be sensitive to ambient environments and need to be worked with under isolated conditions. Examples of such materials include water reactive and pyrophoric chemicals, radioactive isotopes, nanomaterials and biological materials (e.g., cell cultures, viruses or DNA).

Glove Box Hazards

  • Over and under pressurization of glove box
  • Valve failure
  • Ejection of materials when used in conjunction with mechanical, pneumatic or vacuum systems
  • Simultaneous operation by two or more laboratory personnel
  • High voltage
  • Use of incompatible chemicals and/or gases
  • Inappropriate ventilation or exhaustion of vapors
  • Glove breaches and failures

 Anaerobic Chamber Hazards

  • Hydrogen gas use:
    • It is colorless, tasteless, odorless and highly flammable in concentrations between 4%-75% by volume.
    • It may spontaneously ignite in the air and burn with an almost invisible flame.
    • High levels of hydrogen gas or incorrect mixtures of hydrogen gas introduced during purge cycles may cause explosions.
    • Even at low concentrations of hydrogen gas, the use of heated catalysts, incubators, fans and stirrers inside the chamber can serve as ignition sources.
  • Glove breaches and failures

Lessons Learned

Resources

References

Health hazards

Requirement for researchers

UC San Diego researchers working with any chemical that is considered a health hazard must complete a health hazard hazard control plan (HCP) obtained through the Chemical Hazard Use Application (CHUA).

This HCP must be preapproved by the principal investigator prior to beginning any work with this material.

Definition

Health hazard chemicals are those that are classified as causing toxicity: acute health effects, chronic health effects, irritancy or sensitivity. In some cases these materials may also have carcinogenic properties. OSHA defines a health hazard as a chemical for which there is statistically significant evidence based on at least one study conducted in accordance with established significant principles that acute or chronic health effects may occur in exposed employees. The broad definition OSHA uses to define hazardous chemicals includes not only generic chemicals but also paints, cleaning compounds, inks, dyes and other common substances. This is why materials such as borax, Bromophenol blue and cholesterol require a health hazard HCP.

Health Effect Definition

Toxic: A chemical that causes adverse health effects in humans or animals upon exposure. This definition excludes highly toxic materials that are captured in the separate acutely toxic materials HCP.

Acute health effects: Immediate effects caused to humans or animals by the direct, short-term, exposure of a chemical.

Chronic health effects: Long-term effects cause to humans or animals by exposure of a chemical over time; typically weeks, months or years after the exposure occurred.

Irritant: A chemical that causes irritation, either reversible or irreversible, to skin or living tissue at the site of contact; resulting in redness, swelling, itching, or a rash at the site of contact.

Sensitizer: A chemical that upon repeated exposure causes a severe adverse reaction. Allergens are also included in this grouping.

Resources

References

Hydrofluoric acid

Requirement for researchers

UC San Diego researchers working with hydrofluoric acid must complete a hydrofluoric acid Hazard Control Plan (HCP) obtained through the Chemical Hazard Use Application (CHUA).

This HCP must be preapproved by the principal investigator prior to beginning any work with this material. Information on this Blink page is supplementary and is not intended to replace the approved HCP.

Note: If work involving hydrogen fluoride gas or flourine gas is conducted then the compressed gas HCP must be used in conjunction with the Hydrofluoric Acid HCP.

Definition

Hydrogen fluoride (HF) is a colorless, fuming liquid or gas with a strong, irritating odor. It is usually shipped in steel cylinders as a compressed gas. Hydrogen fluoride readily dissolves in water to form colorless hydrofluoric acid solutions; dilute solutions are visibly indistinguishable from water. It fumes at concentrations greater than 48%. Although it is non-flammable, its corrosive action on metals can result in the formation of hydrogen in containers and piping, which creates a fire and explosion hazard.

Liquid hydrofluoric acid is one of the most corrosive acids and can produce serious health effects by any route of exposure. Concentrated HF solutions can cause severe, deep, and disfiguring burns that are extremely painful and slow to heal. These effects are due to the fluoride ion’s aggressive, destructive penetration of tissues, which also binds with calcium in the body. This results in tissue destruction, decalcification of bone, cardiac arrhythmia, liver and kidney damage. Exposure to dilute solutions (concentrations less than 20%) may cause few or no symptoms at first, but may cause severe pain later if not quickly washed off. Calcium gluconate gel will bind to the fluoride ions and prevent further tissue destruction, but it must be applied quickly (even if burns have not been felt) to be effective. Burns may not be painful or visible for several hours and even moderate exposure to concentrated HF can result in fatality.

Breathing HF gas or the vapor from hydrofluoric acid can cause rapid death from throat swelling or from chemical burns to the lungs. Acute symptoms of HF inhalation include coughing, choking, chest tightness, chills, fever and cyanosis. Anyone suspecting of having inhaled HF should seek immediate medical attention and observation of pulmonary effects. 

Special Requirements

  • Labs having hydrofluoric acid in their inventories MUST have calcium gluconate gel within the expiration date accessible in their lab’s first-aid kit. Contact an EH&S Research Assistance Program specialist for supplies.
    • Laboratory personnel should be trained in first-aid procedures for HF exposure before beginning any HF related work.
  • Consult the Chemical Hygiene Safety Officer if work involves large quantities or heating.
  • Hydrofluoric acid attacks glass, concrete, and some metals (especially cast iron and alloys containing silica), organic materials such as leather, natural rubber, wood and human tissue.  Never store HF is a glass container.

Lessons Learned

Resources

Microtome

A microtome, also referred to as a histome or cryostat, is a device that cuts extremely thin sections of tissue for microscopic study. They present a significant risk during operation or cleaning due to very sharp blades.

Requirement for researchers

UC San Diego researchers working with microtomes must follow an approved hazard control plan (HCP) obtained through the Chemical Hazard Use Application (CHUA). This HCP must be preapproved by the principal investigator prior to beginning any work with this equipment. Adhering to the HCP can significantly reduce the risk of possible injury.

Evaluate the hazards

  • Cuts and body injuries can occur when:
    • Placing or removing blocks from the block holder: the blade is in the blade holder and the wheel lock is NOT on; when the block holder sweeps down towards the blade and fingers are in the way.
    • Changing blades.
    • Cleaning the microtome while the blade is in place.
    • Grabbing a ribbon from the blade with fingers.
    • Wiping the face of the block in the block holder while blade is in place.

Injury prevention

  • Avoid using excessive force with blades.
  • Utilize the blade guard.
  • Always lock the wheel when exchanging blocks.
  • Make it your practice to use handles with blades.
  • Slowly and carefully change blades:
    • Always remove blade before cleaning microtome; do NOT leave the blade in a microtome when not in use.
    • Use appropriate tools (such as forceps) when retrieving materials near a blade so hands remain clear;
  • Use a clamping tool to remove and install blades.
  • Always discard blades in a sharps container immediately.
  • Maintain a minimum 1" (or 2.54 centimeters) clearance between your hands and the blade.

 Required mentorship for all users

  • Important: Follow a mentor strategy before beginning work until proficiency using a microtome has been demonstrated.
    • The first time observe.
    • The second time work cooperatively.
    • The third time conduct the microtome work in the presence of a mentor.
    • The fourth time become a mentor — provide feedback to your principal investigator regarding the HCP.

 Lessons learned

Resources

References

  • Title 8, Standard 3558 – Microtomes (Manual, Semiautomatic and Automatic)

Organic peroxides

Requirement for researchers

UC San Diego researchers working with organic peroxides must follow the organic peroxides hazard control plan (HCP) in the Chemical Hazard Use Application (CHUA).

This HCP must be preapproved by the principal investigator prior to beginning any work with this material. Information on this Blink page is supplementary and is not intended to replace the approved HCP.

Never work alone when working with hazardous chemicals.

Definition

Peroxide-forming compounds are among the most hazardous substances commonly handled in laboratories. Organic peroxides contain the peroxide functional group (ROOR), which are sensitive to oxygen, heat, friction, impact, light, and strong oxidizing and reducing agents. Peroxide formation may occur when materials are stored for prolonged periods (even unopened bottles), concentrated through distillation, evaporation or air exposure; and also as a result of polymerization. The unusual stability problems of this class of compounds make them a serious fire and explosion hazard that requires careful management.

Peroxide formation become evident when crystalline solids are observed in the liquid itself or around the bottle’s cap. Some peroxide-forming chemicals produce solutions that appear cloudy. Once peroxides have formed, they can detonate when combined with other compounds or when disturbed by unusual heat, mechanical shock, impact or friction. Visual inspection is the safest way to determine peroxide formation.

Safety precautions

  • Only purchase the minimum amount of material necessary to perform your research.
  • Visually check for crystalline solids before each use.
  • Do not use metal spatulas because contamination by metals can lead to explosive decomposition; use ceramic or plastic spatulas instead.
  • Do not grind or subject organic peroxides to any type of friction or impact.
  • Glass containers that have metals screw cap lids or glass stoppers should not be used; use polyethylene containers, screw caps or stoppers.
  • Protect peroxide formers from heat and light.
  • Follow the labeling and testing requirements per the UC San Diego peroxide formation policy.
  • Frequently review your inventory to prevent peroxide formers from becoming unsafe.
  • Never open or handle old or expired peroxide-forming materials when they are discovered; immediately notify your principal investigator and EH&S.

Identify and label organic peroxide formers

  • Check your inventory against Common Laboratory Chemicals That Form Organic Peroxides.
  • Be aware that the following classes of chemicals include materials that form organic peroxides over time:
    • Aldehydes
    • Compounds containing benzylic hydrogen atoms (particularly if the hydrogens are on tertiary carbon atoms)
    • Compounds containing the allylic structure, including most alkenes
    • Ethers (especially cyclic ethers and those containing primary and secondary alcohol groups
      • MTBE (Methyl tert-butyl ether, also known as methyl tertiary butyl ether) is excluded from this policy and should be considered as a substitute for more hazardous ethers such as diethyl ether when possible.
      • Avoid diisopropyl ether when possible given how easily it forms peroxides.
    • Vinyl and vinylidene compounds

Labeling and inventory management

  • Label peroxide-forming materials clearly and promptly upon receipt or synthesis (including refillable dispensing containers). Include this required additional labeling on peroxide formers (always include name or initials of person recording the information):
    • Date received (ex: 1/1/2010 RCVD, initials)
    • Date opened (ex: 1/1/2010 OPND, initials)
    • Date testing history (ex: 1/1/2010 ND or ‘X’ PPM, initials depending on results)
  • Review your inventory frequently to prevent peroxide formers from becoming unsafe.
  • Use a first-in, first-out inventory — A system using the oldest chemicals first should be implemented to avoid accumulation and degradation of older chemicals and their containers.

peroxide handling

If you discover expired or old peroxide-forming materials

  • DO NOT HANDLE ANY peroxide-forming material that appears suspicious (oily, viscous, crystal formation) OR exceeds 80 ppm using the test parameters outlined below this section.
  • Inform your principal investigator immediately.
  • Inform colleagues in the work area about the hazard.
  • Contact the Chemical Hygiene Officer and your Departmental Safety Officer as soon as possible.
  • Label and isolate the cabinet or area: “Do Not Handle — Dangerous peroxide-forming Material”.
  • Contact EH&S Environmental Management Facility, (858) 534-2753, promptly for proper disposal.
    • See How to Request a Hazardous Waste Collection.
    • Important: Inform EH&S that the material is a suspect, possibly dangerous peroxide former so waste technicians are adequately warned about the hazards before waste disposal pick up or transport.

Testing for peroxy compounds

  1. Opened containers – Test at least every 6 months.
  2. Unopened containers – Start testing for peroxides on the day of the manufacturer's expiration date and every 6 months thereafter. 
  • Review test records prior to distillation or purification.
  • Never test containers of unknown age or origin, or containers that have that fall outside the testing parameters. Old bottles may contain concentrated peroxides or peroxides may have crystallized in the cap threads, presenting a serious hazard when opening.
  • All test records must be traceable. Reference all recorded container information to a written document (e.g., lab notebook). You can use the chemical inventory number on the container if applicable.
  • If you are unsure about the safety of a material, properly dispose of it as hazardous waste.
  • Solvent purification systems under an inert atmosphere are exempt from testing.

Testing procedures

The 3 test methods below will detect most (but not all) peroxy compounds including hydroperoxides.

Peroxide check test strips

Method 1. (Preferred)

  • Use peroxide semi-quantitative test strips with a range of 0-100 ppm (mg/L). Sensitivity and range (ppm or mg/L): 0.0, 0.5, 2.0, 5.0, 10, 25, 50 and 100. Quantity: bottle of 50. Available from Grainger (see image).
  • Record results in ppm on each container. Enter “ND” if peroxides are non-detectable.
    • 0-25 parts per million (ppm) – Compounds testing within this range offer little or no threat of violent reaction on the given test date. For compounds testing in this range, the investigator should consider the addition of fresh inhibitor to retard the auto-oxidation process and the container should be tightly sealed to prevent air and light exposure. Contents may be kept for another 3 months.
    • >25 and <50 ppm – Compounds originally inhibited by the supplier which test within this range may well be on the way to posing a threat to the operations of the laboratory. Remove peroxides or dispose of in a timely fashion.
    • >50 ppm – Any suspect container testing in this range must be considered to be potentially shock sensitive and should therefore not be handled further or moved. High peroxide concentrations may occur without the presence of visible crystals. Contact EH&S for proper disposal as soon as possible.

Method 2.

  • Add 1 - 3 ml of the liquid to be tested to an equal volume of acetic acid, add a few drops of 5% aqueous KI solution, and shake. The appearance of a yellow to brown color indicates the presence of peroxides and therefore the material should be properly disposed of.
    Note: This method is not quantitative.

Method 3.

  • Add 0.5 ml of the liquid to be tested to a mixture of 1 ml of 10% aqueous KI solution and 0.5 ml of dilute HCl to which has been added a few drops of starch solution just prior to the test. The appearance of a blue or blue-black color within a minute indicates the presence of peroxides and therefore the material should be properly disposed of.
    Note: This method is not quantitative.

Common lab chemicals that form organic peroxides over time

The most common compound found in UCSD laboratories that consistently forms dangerous amounts of organic peroxides is diethyl ether.

Use the tables below and the UCSD Hazard Control Plan Classification listing for Organic peroxide-forming Chemicals (Word file) to identify other peroxide formers in your chemical inventory. Note: Lists are illustrative but not exhaustive.

Class I:  Unsaturated materials, especially those of low molecular weight, may polymerize violently and hazardously due to peroxide initiation.
Acrylic acid Tetrafluoroethylene
Acrylonitrile Vinyl acetate
Butadiene Vinyl actylene
Chlorobutadiene (chloroprene) Vinyl chloride
Chlorotrifluoroethylene Vinyl pyridine
Methyl methacrylate Vinylidene chloride
Styrene  

Class II:  The following chemicals are a peroxide hazard upon concentration (distillation/evaporation). A test for peroxide should be performed if concentration is intended or suspected.
Acetal Dioxane (p-dioxane)
Cumene Ethylene glycol dimethyl ether (glyme)
Cyclohexene Furan
Cyclooctene Methyl acetylene
Cyclopentene Methyl cyclopentane
Diacetylene Methyl-i-butyl ketone
Dicylopentadiene Tetrahydrofuran
Diethylene glycol dimethyl ether (diglyme) Tetrahydronaphthalene
Diethyl ether Vinyl ethers

Class III:  Peroxides derived from the following compounds may explode without concentration.
Organic Inorganic
  Divinyl ether   Potassium metal
  Divinyl acetylene   Potassium amide
  Isopropyl ether   Sodium amide (sodamide)
  Vinylidene chloride  

Resources

References

Piranha solution

Piranha solution (also known as piranha etch) is extremely energetic, highly corrosive and potentially explosive. Handle with extreme caution.

Piranha solution is a mixture of sulfuric acid and hydrogen peroxide used to remove organic residues from substrates. Traditional piranha solution is a 3:1 mixture of sulfuric acid and 30% hydrogen peroxide. Some protocols call for as much as 7:1 mixtures.

Requirement for researchers

UC San Diego researchers working with piranha solution must follow an approved hazard control plan (HCP) obtained through the Chemical Hazard Use Application (CHUA).

This HCP must be preapproved by the principal investigator prior to beginning any work with this material.

Never work alone when working with hazardous chemicals.

Special precautions

Required containers, caps and labels

  • Important: UC San Diego requires researchers to use the specific containers, vented caps, and labels listed below for piranha solution. Other pressure generating waste streams also require vented waste containers (examples: base piranha [ammonium hydroxide and hydrogen peroxide], aqua regia, organic solvents containing residual concentrated nitric acid, etc.).

Get free required containers, vented caps, and labels from EH&S:

Resources

Potentially explosive materials

Potentially explosive materials (PEMs) are particularly dangerous because they may explode if subjected to heat, light, friction or mechanical shock. Shock sensitive chemicals also become increasingly sensitive with age. These materials all require careful management due to their capability of posing as a serious threat to health and safety.

PEMs include peroxidizable organic chemicals.

Requirement for researchers

UC San Diego researchers working with potentially explosive materials must follow an approved hazard control plan (HCP) obtained through the Chemical Hazard Use Application (CHUA).

This HCP must be preapproved by the principal investigator prior to beginning any work with this material. Information on this Blink page is supplementary and is not intended to replace the approved HCP.

Never work alone when working with hazardous chemicals.

Storage and inventory management

  • Label potentially explosive materials clearly and promptly upon receipt or synthesis (including refillable dispensing containers).
    • Date received (ex: 1/1/2010 RCVD, initials)
    • Date opened (ex: 1/1/2010 OPND, initials)
  • Review your inventory frequently to prevent PEMs from becoming unsafe.
  • Use a first-in, first-out inventory — A system using the oldest chemicals first should be implemented to avoid accumulation and degradation of older chemicals and their containers.
  • Unless the manufacturer added an inhibitor, closed containers of shock sensitive materials should be discarded after 1 year and open containers discarded within 6 months of opening. Review the label and SDS to determine if the chemical is shock sensitive.
  • Keep explosive chemicals away from all ignition sources such as open flames, hot surfaces, spark sources, and direct sunlight.

If you discover expired or old PEMs

  • DO NOT HANDLE ANY PEM forming material that appears suspicious (crystal formation, discoloration or visible layering)
  • Inform your principal investigator immediately.
  • Inform colleagues in the work area about the hazard.
  • Contact the Chemical Hygiene Officer and your Departmental Safety Officer as soon as possible.
  • Label and isolate the cabinet or area: “Do Not Handle — Potentially Explosive Material”.
  • Contact EH&S Environmental Management Facility, (858) 534-2753, promptly for proper disposal.

Common laboratory PEMs

Commonly used chemicals that can become an explosion hazard under certain conditions:

  • Hydrated picric acid that becomes dry or becomes contaminated with metals which form metal picrate salts.
  • Sodium amide that reacts with air or moisture to form superoxides, as evidenced by yellow or brown discoloration.
  • Certain alkyl nitrates (e.g., butyl nitrate or propyl nitrate) that become contaminated with nitrogen oxides.
  • Certain normally stable perchlorates (e.g., pyridium perchlorate or tetraethylammonium perchlorate) that becomes unstable at elevated temperatures.
  • Organic chemicals that form peroxides through exposure to air or light: Common Laboratory Chemicals That Form Organic Peroxides.

NOTE: Most explosions occur while purifying or distilling mixtures. Therefore, use extreme caution before concentrating or purifying any mixture that may contain an explosive chemical.

Potentially explosive combinations of some common reagents:

  • Acetone + chloroform in the presence of a base
  • Acetylene + copper, silver, mercury, or their salts
  • Ammonia (including aqueous solutions) Cl2, Br2, or I2
  • Carbon disulfide + sodium azide
  • Chlorine + an alcohol
  • Chloroform or carbon tetrachloride + powdered Al or Mg
  • Decolorization carbon + an oxidizing agent
  • Diethyl ether + chlorine (including a chlorine atmosphere)
  • Dimethyl sulfoxide + an acyl halide, SoCl2, or POCL3
  • Dimethyl sulfoxide + CrO3
  • Ethanol + calcium hypochlorite
  • Ethanol + silver nitrate
  • Nitric acid + acetic anhydride or acetic acid
  • Picric acid + a heavy metal, such as Pb, Hg, or Ag
  • Silver oxide + ammonia + ethanol
  • Sodium + a chlorinated hydrocarbon
  • Sodium hypochlorite + an amine

Explosive and potentially explosive chemical families

  • PEM Lists (PDF)

Lessons Learned

Resources

Pyrophoric materials

Pyrophoric materials require extra caution during use, storage, and disposal because of severe reactive properties. These materials ignite spontaneously when exposed to air. Handle them with extreme care to avoid contact with air and moisture. Failure to handle these materials properly may result in serious injury or death.

Important: Pyrophoric materials may only be stored and used in completely fire sprinkled buildings, per California Fire Code.

Requirement for researchers

UC San Diego researchers working with pyrophoric materials must follow an approved hazard control plan (HCP) obtained through the Chemical Hazard Use Application (CHUA).

This HCP must be preapproved by the principal investigator prior to beginning any work with this material.

gloves for pyrophorics

Never work alone when working with hazardous chemicals.

Gloves (EH&S provided) – For work with liquid pyrophoric chemicals outside of a glove box, appropriate hand protection must include chemically resistant outer gloves (Ansell 25-201 NeoTouch® neoprene gloves) on top of an approved flame resistant (FR) inner glove or glove liner (Ansell 70-200 Kevlar Liner gloves). If flame-resistant gloves compromise dexterity due to the nature of the work, contact the Chemical Safety Officer (858-822-1579) for guidance. Never reuse disposable gloves.

Definition

The Globally Harmonized System of Classification and Labeling of Chemicals (GHS) defines pyrophoric as the following:

Pyrophoric Liquids — "A pyrophoric liquid is a liquid which, even in small quantities, is liable to ignite within five minutes after coming into contact with air. Substances and mixtures of this hazard class are assigned to a single hazard category on the basis of the outcome of the UN Test N.3 (UN Manual of Tests and Criteria).

Pyrophoric Solids — "A pyrophoric solid is a solid which, even in small quantities, is liable to ignite within five minutes after coming into contact with air. Substances and mixtures of this hazard class are assigned to a single hazard category on the basis of the outcome of the UN Test N.2 (UN Manual of Tests and Criteria)."

Pyrophoric listings

Use the listings below to find out if your chemical inventory includes pyrophoric materials.

Pyrophoric materials HCPs come in two possible categories of Hazard Control Plan templates: 

1) CSSC Approved also known as material specific HCPs. These templates are approved by the UC San Diego Chemical Safety & Surveillance Committee (CSSC) for work with materials identified as high hazard chemicals:

  • Arsine
  • Phosphine
  • Tert-butyllithium
  • Germane
  • Diborane
  • Silane

2) EH&S Reviewed also known as group templates. These are standard Hazard Control Plan templates for work with thousands of other chemicals grouped by hazard classification:

  • Pyrophoric

These HCPs must be preapproved by the principal investigator prior to beginning any work with these materials. Detailed instructions must be included within the Lab Specific Instructions section of the HCP.

Information on this Blink page is supplementary and is not intended to replace the approved HCP.

  • Video: Watch How to Handle Pyrophoric Reagents, a 3-part instructional video produced by UC San Diego Department of Chemistry & Biochemistry in partnership with Environment, Health & Safety.

Resources

References

Reproductive hazards

Requirement for researchers

UC San Diego researchers working with any chemical that is considered a reproductive hazard must complete a reproductive hazard hazard control plan (HCP) obtained through the Chemical Hazard Use Application (CHUA).

This HCP must be preapproved by the principal investigator prior to beginning any work with this material.

Definition

A reproductive hazard is a substance that has an adverse effect on the reproductive capabilities including chromosomal damage, effects on fetuses, male and female fertility and the development of offspring. These hazards may cause problems such as infertility, miscarriage and birth defects.

Use the listings below to find out if your chemical inventory includes reproductive hazards:

  • Chemicals Known to the State to Cause Cancer or Reproductive Toxicity (PDF), California Environmental Protection Agency
    • The lists above serve as guides and are not all inclusive. Review the Safety Data Sheet for other materials not listed.

Resources

References

Sodium azide

Requirement for researchers

UC San Diego researchers working with sodium azide must complete a sodium azide hazard control plan (HCP) obtained through the Chemical Hazard Use Application (CHUA).

This HCP must be preapproved by the principal investigator prior to beginning any work with this material. Information on this page is supplementary and is not intended to replace the approved HCP.

Definition

Sodium azide is an inorganic, rapidly acting, highly toxic, odorless white solid chemical. It is also very reactive, decomposing explosively upon shock, heating, or friction. Sodium azide is usually used in dilute solutions as a chemical preservative for samples and stock solutions in research labs and in clinical applications. In other research applications, such as synthesis, the use of pure sodium azide and solutions of 5% or greater present serious physical and health hazards; however, health hazards apply regardless of usage. It is acutely toxic by all routes of exposure and should be handled with extreme care. It may be fatal if swallowed or absorbed through the skin. Symptoms of exposure are similar to those of cyanide and even small amounts may include hypotension, hypothermia, headache, shortness of breath, faintness, cough, skin burns and blisters, and convulsions with permanent damage targeting the heart and brain.

Special Handling Requirements

  • Avoid disturbing sodium azide chemical containers when not actively using and avoid exposing concentrated sodium azide to friction, heat or shock.
  • Never store sodium azide in metal containers or on metal shelves. The chemical will react to form explosive metal azides.
  • Do not use metal items, such as metal spatulas, to manipulate. Use Teflon spatulas instead.
  • Do not use a HEPA vacuum for cleaning up sodium azide — the chemical could react explosively with the metal inside the vacuum.
  • Do not pour sodium azide solutions down the drain, even at low concentrations — the chemical could react explosively with the metal inside the drain piping.
    • Hematology equipment that uses sodium azide and generates liquid waste must not be piped to the drain. The buildup of sodium azide salts in the piping system have led to serious explosions in the plumbing infrastructure. For proper and safe disposal of hemostatis system equipment waste, please contact the EH&S Chemical Hygiene Officer, (858) 822-1579.
  • Sodium azide should not be allowed to come into contact with the following, as sensitive and/or unstable compounds can be formed: 
    • Heavy metals or their salts (including barium, lead, and copper)
    • Nitric acid and other acids (acids can also form the highly toxic and volatile hydrazoic acid).
    • Chlorinated solvents such as dichloromethane and chloroform, bromine, and dimethyl sulfate.

Lessons Learned

Resources

Strong corrosives

Corrosive chemicals are substances that cause the destruction of living tissue at the site of contact, or are highly corrosive to steel. Corrosive chemicals can be solid, liquids, or gases and can affect the eyes, skin and respiratory tract. These materials are probably the most common toxic substances encountered in the laboratory and can be especially dangerous because their effects on tissue generally takes place very rapidly.

Strong corrosives have a pH of 2 or lower or a pH of 12.5 or higher. Most acids are liquids and most bases are solids. Acids react with many metals and can be in themselves, strong oxidizing agents. They also have the ability to produce fires or explosions by combination with combustible materials. It is imperative to follow all strong corrosive incompatible and reactivity segregation guidelines.

Requirement for researchers

UC San Diego researchers working with strong corrosives must follow an approved hazard control plan (HCP) obtained through the Chemical Hazard Use Application (CHUA).

This HCP must be preapproved by the principal investigator prior to beginning any work with strong corrosive chemicals.

Never work alone when working with hazardous chemicals.

Note that the following corrosive chemicals require their own separate HCP: chlorine, hydrofluoric acid, hydrogen peroxide, strong oxidizers, trifluoroacetic acid and piranha solution.

Special Handling

  • Always be vigilant about wearing laboratory PPE; corrosive chemicals pose serious hazards to dermal and eye exposures.
  • Never store corrosive materials above eye level.
  • Always add acids and bases to water; NEVER water to acids and bases.
  • When mixing corrosive solids with water, always add slowly the corrosive solid to the water stirring continuously. Cooling may also be necessary.
  • If the potential exists for explosion or a high-thermal reaction, additional shielding must be utilized. This may include working in a fume hood or a glove box, using a portable shield and donning a face shield.
  • If there is a possibility of corrosive chemical dust generation or fumes/vapors, conduct the work in a fume hood. Always ensure that there is adequate ventilation.
  • Always store corrosive materials away from heat, flames, oxidizers and water sources.
  • Always segregate acids and bases in storage.
  • Keep chemical containers closed and store in an acid-resistant secondary container.
  • If you need to transport corrosive chemicals utilize a bottle jacket; Marketplace offers 4L/1G sizes:
    • Grainer Catalog Number: 1YNJ4
    • Sigma-Aldrich Catalog Number: Z194441
    • Fisher Catalog Number: 1798579
    • VWR Catalog Number: 56610-100

Acid/Base baths

  • Potential Hazards
    • Inhalation of noxious corrosive fumes.
    • Skin contact of concentrated acids/bases.
    • Uncontrolled release of corrosive chemicals down the sink drain/environment.
  • Generation and disposal of an acid/base bath must always have the approval of the PI.
    • Always wear the mandatory laboratory PPE.
    • Additional PPE may include a chemical splash apron, rubber gloves, and face shield.
  • Clearly label acid/base bath containers
      • All containers, even those containing just water or bleach must be clearly labeled (not just the lids).
      • Include the chemical’s hazard on the container; i.e.: “10% bleach, Corrosive”.
      • Consider using different colored containers for acid and base baths.
  • Lessons learned

bottle jacket for corrosive chemicals

Bottle jacket for transporting corrosive chemicals.

Resources

Strong oxidizers

Requirement for researchers

UC San Diego researchers working with any chemical that is considered a strong oxidizer must complete a strong oxidizers hazard control plan (HCP) obtained through the Chemical Hazard Use Application (CHUA).

This HCP must be preapproved by the principal investigator prior to beginning any work with this material. Information on this Blink page is supplementary and is not intended to replace the approved HCP.

Never work alone when working with hazardous chemicals.

Strong oxidizer listings

Strong oxidizer HCPs come in two possible categories of HCP templates: 

1) CSSC Approved also known as material specific HCPs. These templates are approved by UC San Diego's Chemical Safety & Surveillance Committee (CSSC) for work with materials identified as high-hazard chemicals, such as:

  • Bromine
  • Chlorine
  • Fluorine
  • Hydrogen peroxide
  • Osmium tetroxide
  • Piranha solution

2) EH&S Reviewed also known as group templates. These are standard HCP templates for work with thousands of other chemicals grouped by hazard classification:

  • Strong oxidizers
  • Compressed gas

Definition

Oxidizing chemicals are materials that provide oxygen to cause/contribute to the combustion of other materials at room temperature or with slight heating. Strong oxidizing agents are capable of creating fire and explosive reactions when combined with combustible, organic or easily oxidized materials. This class of chemicals includes peroxides, chlorates, perchlorates, nitrates and permanganates.

In addition to the physical hazards, the health hazards of strong oxidizers can be severe. The combustion products of oxidizer-fed fires are generally much more toxic than the combustion products of the combustible material itself in air and can cause potentially lethal chemical pulmonary edema even with brief exposures. Oxidizers are also generally corrosive; tissues such as lung, skin and eyes are at risk, which will depend on the oxidizer and its concentration. Skin exposure can result in dangerous burns, but dermatitis is more common. Eyes are much more sensitive to exposure.

Example of Strong Oxidizers
Barium perchlorate Picric acid
Chromic acid Potassium bromate
Niitrogen trioxide Sodium chlorate
Perchloric acid Sodium perchlorate

Special handling

  • Heating perchloric acid must only be done in a perchloric acid designed/designated fume hood that is marked as for use ONLY with perchloric acid and not any other materials unless approved by the Chemical Safety Officer.
  • Store oxidizers away from organic, flammable, dehydrating, or reducing agents.
  • Never store oxidizers in wooden cabinets or on wooden shelves.
  • Provide secondary containment for strong oxidizing acids such as perchloric and chromic acid.
  • Do not use corks or rubber stoppers.
  • Reaction vessels containing oxidizing material should be heated in a mantle or sand bath. Oil baths should not be used.
  • Do not let combustible solids such as paper towels, lab coats and clothing become contaminated with oxidizers. Should this happen, immediately soak and rinse well with water to remove oxidizer.
  • Do not use potentially reactive oxidizer mixtures outside of accepted temperature ranges. The additional heat may initiate violent or even explosive reactions.
  • Perchloric Acid Guidelines
  • Picric Acid Guidelines

Resources

References

Trifluoroacetic Acid

Requirement for researchers

UC San Diego researchers working with trifluoroacetic acid must complete a trifluoroacetic acid Hazard Control Plan (HCP) obtained through the Chemical Hazard Use Application (CHUA).

This HCP must be preapproved by the principal investigator prior to beginning any work with this material. Information on this Blink page is supplementary and is not intended to replace the approved HCP.

Note: Trifluoroacetic Acid (TFA) in this HCP refers to Neat TFA. Any dilutions of TFA are handled using standard chemical safety practices.

Definition

Trifluoroacetic acid is a noncombustible colorless liquids with a sharp pungent odor and is highly corrosive. It is miscible in water. Contact of the liquid with the skin, eyes, and mucous membranes can cause severe burns, and ingestions can result in serious damage to the digestive tract. TFA vapor is highly irritating of the eyes and respiratory tract, and inhalation of high concentrations can lead to severe destruction of the upper respiratory tract and may be fatal as a result of pulmonary edema. Symptoms of overexposure to TFA vapor include a burning feeling, coughing, headache, nausea and vomiting.

Lessons Learned

Resources

Water reactive materials

Requirement for researchers

UC San Diego researchers working with any chemical that is considered a water reactive hazard must complete a water reactive hazard control plan (HCP) obtained through the Chemical Hazard Use Application (CHUA).

This HCP must be preapproved by the principal investigator prior to beginning any work with this material. Information on this Blink page is supplementary and is not intended to replace the approved HCP.

  • When using piranha solution you must follow the EH&S approved piranha solution HCP (above).
  • Never work alone when working with hazardous chemicals.

Definition

Water reactive materials can react violently with water or atmospheric moisture to produce gas and heat. The most common water reactive chemicals include sodium, potassium, lithium metals and aluminum alkyls. The risks associate with a specific chemical depends on its reactivity and the nature of the gaseous product (flammable, toxic or both). The mutual production of flammable gas and heat can lead to spontaneous ignition or explosion. Typical gasses produced are: H2, CH4, H2S, NH3, PH3, HCN, HF, HCl, HF, HI, SO2, SO3. Prior to working with any water reactive chemicals you must identify which gas may be formed in case of exposure to water and learn the risks associate with this gas.

  • Remember that water reactive material may present additional hazards. These chemicals may also be classified as corrosives, acutely toxic materials.

NOTE: When handling air-sensitive materials, be prepared for the unexpected. For example, at least one extra set of clean, dry syringes and needles or double-tipped needles should always be available in case the first set of equipment becomes plugged. When working with these air-sensitive reagents keep in mind that these solutions should never be allowed to come in contact with the atmosphere. The reaction rate of solid material (and therefore heat and gas generation) depends on the material’s surface area; therefore smaller particle size increases the hazards associated with these materials.

Quenching — Any unused or unwanted water reactive materials must be destroyed by following the specific destruction procedure(s) included in the Lab Specific Instructions section of the HCP. Design a quenching scheme for residual materials prior to use. Begin quenching with a low-reactivity quenching agent and slowly add more.

Safety precautions

  • Safety shielding is required anytime there is a risk of explosion, splash hazard or a highly exothermic reaction. This includes using the fume hood sash to the lowest feasible position and/or a portable shield.
  • Work under an inert atmosphere (e.g., argon, nitrogen) in a glove box when possible.
  • Work away from water sources or where there is a potential of a water splash.
  • Keep materials in a dry place such as a desiccator, a dry box, or glove box.
  • Store under an inert atmosphere when not in use.
  • Store in a location separated by bases, oxidizing and other incompatible materials.
  • Never return excess chemicals to the original container.
  • Never use water to extinguish fires caused by water reactive materials; use a Class D extinguisher only.
  • Always thoroughly inspect the area for residual reactive materials at the end of each project.

Resources

References

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