Environmental Health and Safety

Laboratory Safety Manual - 2011

V. Procedures for Specific Classes of Hazardous Chemicals

  1. Flammable Liquids
  2. Oxidizers
  3. Corrosives (Acids and Bases)
  4. Reactives
  5. Compressed Gas Cylinders
  6. Nanomaterials

This section offers specific guidelines for working with common hazardous materials that, for varying reasons, may pose a significant risk to human life and health if used improperly. Six fundamental classes of laboratory chemicals will be discussed; flammables, corrosives, oxidizers, reactives, compressed gases, and nanomaterials. These classes of chemicals may include chemicals that are also covered in the previous section regarding their property of toxicity.

Note that the hazard characteristics of the classes of hazardous chemicals are generalized. Check the MSDS to determine the specific hazard characteristics for the chemical before using it.

1. Flammable Liquids

  1. Terms and Definitions

    Flammable liquids are among the most common chemicals found in a laboratory.  The primary hazard associated with flammable liquids is their ability to readily ignite and burn.  The vapor of a flammable liquid, not the liquid itself, can ignite and start a fire.
  1. Use and Storage of Flammables
  1. Health Hazards Associated with Flammables
    The vapors of many flammables are irritating to mucous membranes of the respiratory system and eyes. Routes of entry with corresponding symptoms are listed below.

Acute Health Effects

Chronic Health Effects
The chronic health effects will vary depending on the specific chemical, the duration of the exposure and the extent of the exposure. However, damage to the lungs, liver, kidneys, heart and/or central nervous system may occur. Cancer and reproductive effects are also possible.

Flammable Groups Exhibiting Similar Health Effects

  1. First Aid Procedures for Exposures to Flammable Materials
  1. Personal Protective Equipment (PPE)
    Fume hoods should be used when working with flammable liquids. Nitrile and neoprene gloves provide protection against most flammables. Wear a fire-resistant lab coat to provide a barrier to your skin. Safety goggles/glasses should be worn if there is a splash risk.

    photo of proper PPE
    Proper PPE

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2. Oxidizers

  1. General Characteristics
  1. Examples of Common Oxidizers



  1. Use and Storage of Oxidizers
  1. Use and Storage of Perchloric Acid
  1. Health Hazards Associated with Oxidizers
    Acute Health Effects:

    Some oxidizers such as nitric and sulfuric acid vapors, chlorine, and hydrogen peroxide
    act as irritant gases.  All irritant gases can cause inflammation in the surface layer of
    tissues when in direct contact.  They can also cause irritation of the upper airways,
    conjunctiva, and throat.

Chronic Health Effects:
Nitrobenzene and chromium compounds can cause hematological and neurological changes. Compounds of chromium and manganese can cause liver and kidney disease.  Chromium (VI) compounds have been associated with lung cancer.

  1. First Aid
    If a person has inhaled, ingested or come into direct contact with these materials, the person should be removed from the immediate area as quickly as possible. Seek medical attention immediately.  Rinse with a safety shower for at least 15 minutes if there is direct skin exposure.  Flush with an eyewash for at least 15 minutes if there is direct eye exposure.
  2. Personal Protective Equipment (PPE)
    Neoprene, polyvinyl chloride (PVC), or nitrile gloves are acceptable.  Consult a glove compatibility chart to ensure the glove material is appropriate for the particular chemical you are using.

    Safety glasses must be worn if the potential for splashing or exposure to vapor/gas exists.

    Oxidizers should be used in a chemical fume hood due to the inhalation hazard risk.
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3. Corrosives (Acids and Bases)

  1. General Characteristics
  1. Examples of Corrosives

Sulfuric Acid
Ammonium Hydroxide

Chromic Acid


  1. Use and Storage of Corrosives
  1. Use and Storage of Hydrofluoric Acid

Health Hazards Associated with Corrosives
All corrosives possess the property of being severely damaging to living tissues.  Acids also react with other materials such as metals.

Skin contact with alkali metal hydroxides (e.g., sodium hydroxide and potassium hydroxide) is more dangerous than with strong acids. Contact with base metal hydroxides normally causes deeper tissue damage because there is less pain than with an acid exposure. The exposed person may not wash it off thoroughly enough or seek prompt medical attention.

All hydrogen halides are acids that are serious respiratory irritants and also cause severe burns.

Acute Health Effects

Chronic Health Effects
Symptoms associated with a chronic exposure vary greatly depending on the chemical. For example, the chronic effect of hydrochloric acid is damage to the teeth; the chronic effects of hydrofluoric acid are decreased bone density, fluorosis, and anemia.

  1. First Aid
  1. Personal Protective Equipment (PPE)
    Always wear the proper gloves when working with corrosives. Neoprene and nitrile gloves are effective against most acids and bases. Polyvinyl chloride (PVC) is also effective for most acids. A rubber coated apron and goggles should also be worn. If splashing is likely to occur, wear a face shield over the goggles. Always use corrosives in a chemical fume hood.
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4. Reactives

  1. General Characteristics
    Polymerization Reactions
    Polymerization is a chemical reaction in which two or more molecules of a substance combine to form repeating structural units of the original molecule.  This can result in an extremely high or uncontrolled release of heat. An example of a chemical which can undergo a polymerization reaction is styrene.

Water Reactive Materials

Alkali Metals:
 -Lithium, Sodium, Potassium



Several organometallic compounds

Peroxide-Forming Materials

Diisopropyl Ether
Sodium Amide

Potassium Amide
Diethyl Ether 
Vinyl Ethers

Peroxide Testing
For certain classes of compounds (e.g., ethers as peroxide formers), the date the container was opened should be written on the label. Peroxide formers should have the test history and date of discard written on the label as well.

The following tests can detect most (but not all) peroxy compounds, including all hydroperoxides:

-Add 1 to 3 milliliters (mL) of the liquid to be tested to an equal volume of acetic acid, add a few drops of 5% aqueous potassium iodide solution, and shake.  The appearance of a yellow to brown color indicates the presence of peroxides. Alternatively, addition of 1 mL of a freshly prepared 10% solution of potassium iodide to 10 mL of an organic liquid in a 25-mL glass cylinder should produce a yellow color if peroxides are present.

-Add 0.5 mL of the liquid to be tested to a mixture of 1 mL of 10% aqueous potassium iodide solution and 0.5 mL of dilute hydrochloric acid 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.

-Peroxide test strips, which turn to an indicative color in the presence of peroxides, are available commercially.  Note that these strips must be air dried until the solvent evaporates and then exposed to moisture for proper operation.

None of these tests should be applied to materials (such as metallic potassium) that may be contaminated with inorganic peroxides.

Note: Peroxide test strips are available through the chemical storeroom in Welch.

Other Shock-Sensitive Materials

Chemicals containing nitro-functional groups
Hydrogen Peroxide (30% +)
Ammonium Perchlorate
Benzoyl Peroxide (when dry)
Compounds containing the functional groups: acetylide, azide, diazo, halamine, nitroso, and ozonide.

  1. Use and Storage of Reactives

Water Reactive Materials
Store water-reactive chemicals in an isolated part of the lab. A cabinet removed from water sources, such as sinks, emergency showers, and chillers, is an appropriate location.  Clearly label the cabinet "Water-Reactive Chemicals – No Water".

Store pyrophorics in an isolated part of the lab and in a clearly marked cabinet. Be sure to routinely check the integrity of the container and have the material disposed of through EHS if the container is corroded or otherwise damaged.

Additional safety guidance on pyrophorics can be found at: http://www.utexas.edu/safety/ehs/lab/pyrophorics.html

Peroxide-Forming Materials

Other Shock Sensitive Materials
Store these materials separately from other chemicals and in a clearly labeled

Never allow picric acid (Bouin’s solution) to dry out, as it is extremely explosive. Always store picric acid in a moist environment.  

  1. Health Hazards Associated with Reactives
    Reactive chemicals are grouped as a category primarily because of the safety hazards associated with their use and storage and not because of similar acute or chronic health effects. For health hazard information on specific reactive materials consult the MSDS, the manufacturer, or EHS. However, there are some hazards common to the use of reactive materials. Injuries can occur due to: heat or flames, inhalation of fumes, vapors, reaction products, and flying debris.

    First Aid
    If someone is seriously injured, the most important step to take is to contact emergency responders as quickly as possible.  Explain the situation and describe the location clearly and accurately.

    If someone is severely bleeding, put on protective gloves and apply a sterile dressing, clean cloth, or handkerchief to the wound. Then place the palm of your hand directly over the wound and apply pressure and keep the person calm. Continue to apply pressure until help arrives.

    If a person's clothes are on fire, he or she should drop immediately to the floor and roll. If a fire blanket is available, put it over the individual. An emergency shower, if one is immediately available, can also be used to douse flames.

    If a person goes into shock, have the individual lie down on their back (if safe to do so) and raise the feet about one foot above the floor.

    Personal Protective Equipment (PPE)
    Wear appropriate personal protective clothing while working with highly reactive materials. This might include: impact resistant safety glasses or goggles, a face shield, gloves, a flame-resistant lab coat (to minimize injuries from flying glass or an explosive flash), and a blast shield. Conduct work within a chemical fume hood as much as possible and pull down the sash as far as is practical. While the project does not require you to reach into the fume hood, keep the sash closed.

    Barriers can offer protection of personnel against explosions and should be used. Many safety catalogs offer commercial shields which are commonly polycarbonate and are weighted at the bottom for stability. It may be necessary to secure the shields firmly to the work surface.
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5. Compressed Gas Cylinders

  1. General Characteristics
  1. Purchase Policy
    Purchase of gases in non-returnable cylinders is restricted by policy at UT Austin.  The UT Austin Gas Cylinder policy, which went into effect in May 1993, requires that all gas cylinders purchased for use on campus must be returnable to the vendor. The only exception to this policy is for a compelling research reason. The original policy indicated such exceptions would require prior approval and that a $1,000 deposit would be required to cover potential disposal costs. The specific procedures to be followed to request permission to purchase a research gas in a non-returnable gas cylinder are outlined below.

    The Principal Investigator (PI) should prepare a request for an exception and include the reason why a non-returnable gas cylinder purchase is essential. This request must contain a Letter of Credit commitment that specifically states the requesting PI will be responsible for the proper disposal of the non-returnable cylinder and agrees to pay a $1,000 disposal fee if UT Austin is required to dispose of the cylinder. This request should be submitted to the department chair and the dean for review and approval. The request should then be forwarded to the Provost for final action. Please note: identification of a specific account or funding source by the PI for the possible $1,000 disposal expenditure is not required but approval by the department and the college constitutes a commitment by them that department or college funds are available to cover disposal costs if the PI is unable to cover these costs.

    A copy of the approval request will be returned to the PI and a copy will be forwarded to EHS. The PI should attach a copy of the approved request to the purchase order used to obtain the desired gas.

    Final disposal of the non-returnable gas cylinder should be completed no later than three years after purchase unless written approval for an extension is obtained from the Provost upon recommendation of the chair and dean. Evidence of the proper disposal of the cylinder must be provided to EHS. If the cylinder is disposed of through normal channels (e.g. the EHS Hazardous Waste Program) at no extra cost to UT Austin, the $1,000 Letter of Credit commitment will be canceled. The cylinder will be acceptable for normal waste disposal if the valve has been removed from the cylinder and the cylinder has been cleaned. Similarly, if the cylinder has been returned to the manufacturer or distributor, and this is verified in the form of a receipt or a bill of lading, the Letter of Credit commitment will be canceled. If however, the university must dispose of the cylinder outside of normal procedures because of the cylinder's condition (e.g. damaged or corroded valve) the disposal fee of $1,000 will be assessed to the PI. It is the responsibility of the PI to provide an appropriate account for this charge at that time.
  2. Use and Storage
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6. Nanomaterials (UNDER DEVELOPMENT)

Guidance regarding the safe use of nanomaterials is under development. Contact EHS Lab Safety for assistance.