Identifying Hazardous Chemicals

University departments, units, and/or laboratories are required to inform employees of chemical hazards if the chemical itself is hazardous or if it can release a hazardous component during normal use or accidental discharge. Chemicals include gases and liquids stored in gas cylinders, and solids if a hazardous chemical could be released during possible work tasks. The following table shows the different ways of identifying whether a chemical must be included in the HazCom program. Click on the links for more complete information on each situation.

Explanatory Table of Actions Needed when Identifying HazCom Chemicals
SituationExamplesYour Actions
A container received from a supplier holds a chemical, or a product is known to have hazards
  • Bottle of acetone
  • Compressed gas cylinder
  • Lead brick
  • Check label, MSDS, and other reference materials and determine that it’s hazardous
  • Add to MyChem inventory
  • Keep labels in good condition
  • Train employees
Personnel mix up a process chemical and keep for future use
  • Dilution of a concentrated acid
  • Solvent mixture poured into process reservoir
  • Check sources and determine that it’s hazardous
  • Note in SOPs or JHAs
  • Label container
  • Train employees
A procedure generates potentially hazardous contaminants from “non-hazardous” materials
  • Melting glassware
  • Cutting nylon rope or plastics with a “hot knife”
  • Sanding lumber
  • Recognize the hazard
  • Note in SOPs, JHAs or Health and safety plan
  • Train employees
Personnel receive “exempt” materials from a supplier
  • Cosmetics, food, food additives, beverages, liquor, tobacco, or tobacco products for human consumption
  • Drugs as pills or tablets (including any in first aid kits)
  • Biological materials with no chemical hazards
  • Sealed radioactive sources
  • Check that materials are indeed exempt (no other actions needed for those materials)
Personnel use small quantities of “consumer products”
  • Spray furniture polish used to clean your office’s desktops
  • Marker pen used to highlight dates on a chemical container label
  • Check that materials are indeed consumer products used as a typical consumer may use them (no other actions needed for those materials)*
Personnel use large quantities of “consumer products” containing a hazardous chemical
  • Glass cleaner used throughout a shift
  • Several cans of aerosol spray paint used each day
  • Identify that use is intensive
  • Note in SOPs, JHAs or Health and safety plan
  • Add to MyChem inventory
  • Train employees

*If small amounts of consumer products are the only materials used by the employees, you must inform them about the HazCom program in general.

Contained Hazardous Chemicals

To identify whether a container holds hazardous chemicals:

  • Look on the label and Material Safety Data Sheet/Safety Data Sheet (MSDS/SDS) for words such as "Danger", "Caution", "Warning", or containing warnings such as "irritant", "flammable", "sensitizer", "corrosive", "carcinogenic", etc., or that indicate that personal protective equipment such as chemical-protective gloves or a respirator may be needed if the chemical is used or spilled.
  • Also, a chemical should be identified as hazardous if there is a hazard coding with words, numbers, or colors such as from the NFPA (National Fire Protection Agency) or HMIS (Hazardous Materials Information System) of "1" or greater or it is noted as having a "chronic" hazard.
  • Also, a chemical must be identified as hazardous if there is any known, documented evidence that the chemical or its chemical byproducts formed from normal use may cause a known health effect, or if evidence shows there is a physical hazard due to the chemical’s properties of being flammable, or a combustible liquid, a compressed gas, an explosive, an organic peroxide, an oxidizer, or is pyrophoric, unstable (reactive), or water-reactive.

Mixed hazardous chemicals

Mixtures, dilutions and chemically-reacted preparations generated in the work area such as stock solutions produced for laboratory procedures do not need to be listed in the MyChem inventory, but other aspects of the UW Chemical HazCom program may need to be met. For example, the container must be labeled unless the preparation will be immediately used up. (Go here for information on labeling the container.) Also, employees may need to be trained on the chemical’s hazards depending on whether possible reactions increased or created new hazards. With respect to determining the hazards if a mixture is prepared in house:

  • If there is knowledge about the hazards of the mixture, identify those hazards, label containers appropriately and train employees accordingly.
  • If there is no knowledge about the mixture as a whole, assume the hazards are consistent with the hazards of the constituent components, unless
  • A reaction has proceeded in the mixture which is likely to have changed the chemical’s nature, at which point the hazards of similar reacted mixtures can be used to presume hazards if no better information is available.

Contaminants caused by work processes

Your work processes using non-toxic materials may actually cause potentially hazardous exposures. If you have situations such as the following examples, and similar activities, do not add the materials to your MyChem inventory and do not label the materials, but the processes should be evaluated as part of the hazard assessment steps described here. Training covering the hazards and the protective measures for such “non-traditional chemical” exposures must be done as part of your chemical hazard communication training program if you have indications from your work place or from other work places with similar activities that such exposures may injure workers. Contact EH&S (206-543-7388) if you have questions about making this determination.

  • Melting glassware to re-shape it.
  • Disturbing guano during a field trip to a cave.
  • Using a “hot knife” to cut nylon rope or plastics.
  • Handling animals in research causing release of allergens.
  • Entering university buildings which may have asbestos in the building’s walls.
  • Cutting or sanding lumber which could create possibly hazardous sawdust levels.
  • Activating a fire suppression system that may have chemicals stored outside your work area but could discharge into your work area.

Exempt materials

The following materials are exempt from the UW Chemical HazCom Program. They do not need to be listed in the MyChem inventory nor MSDSs maintained, but labeling, training, and controls may be required by other safety programs:

  • Food, food additives, beverages, liquor, tobacco, tobacco products and cosmetics intended for human consumption or use (unless adulterated for research purposes or academic programs).
  • Drugs that are in the final form of a pill or tablet for delivery to a patient (including those kept in a first aid kit).
  • Materials whose only hazard is biological.
  • Sealed radioactive sources.
  • Hazardous waste.

Consumer products

Other types of hazardous material that may be exempt are small quantities of consumer products packaged for distribution to and use by the general public that are used in the same manner and frequency for office, janitorial, or minor maintenance purposes (such as pens, markers, glass cleaner, furniture polish, etc.). These materials are exempt from the inventory and MSDS maintenance requirements as long as the use does not exceed that of a typical consumer. Supervisors whose employees may use a consumer product for an extended period during a work shift should include the item on the MyChem inventory and train employees concerning the item’s hazards.

If you have questions about identifying hazardous materials, contact EH&S at 206-543-7388 or