Container Labeling

Newly-Received Chemicals

Chemical containers must have an acceptable label when received from the manufacturer or they must be rejected and returned to the manufacturer. The information on the label must be legible and in English and include the chemical's identity, its hazards, and the name and address of the manufacturer.

Workplace Labeling of Containers

If a container label becomes illegible during use or if a hazardous chemical is transferred from its original container to a second container, the container must have affixed to it an extra copy of the original container label, or a legible hand-written label that includes the required information, or a generic label (available from various vendors) either pre-printed or filled in with the required information.

Exemption: If the chemical is put into a second container that will be under the direct control of the individual who transferred it and all of it will be consumed during the same shift, then the second container does not need to be labeled.

At a minimum, the chemical container label must identify:

  • The name of the chemical
  • Any signal word ("Danger" or "Warning") if labeled per GHS
  • The chemical's physical hazards and health hazards, including specific target organs if they are at special risk, and including all hazards which are identified with the signal words "Danger" or "Warning" if the chemical is classified per the GHS

The label may include other information such as the date the chemical was received, the date a container was opened (if the chemical could degrade or react over time), the amount of chemical still remaining in the container, the initials of the person who prepared the formulation, or any other information useful for safe and efficient operations.

Labeling Substances Prepared In-House

Reagents, stock solutions, and bulk quantities of chemicals mixed for in-house processes also need to be labeled with identification as to the chemical and its hazards unless the container will be emptied that work shift. The chemical name may be a standard name for that mixture as described in the literature or by an equipment manufacturer's recommendation, or the name associated with the chemical in a specific step of the Standard Operating Procedure, or the name could be the list of the constituent components.

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 on the label.
  • If there is no knowledge about the mixture as a whole, identify the constituent components and their hazards, unless
  • A reaction has proceeded in the mixture which is likely to have changed the chemical’s nature but there is no historical information about that specific reaction's hazards, at which point the hazards of similar reacted mixtures can be used to anticipate the hazards. You should be cautious of other possible, unexpected hazards if this approach is necessary.

Unusual Labeling Situations

Long runs of tubing or piping, containers too small for labels, containment vessels installed into a process but may leak or be opened, containers which would become unusable for their intended purpose if labeled with a marker or large adhesive-based label and which will hold chemicals beyond the end of the shift of the individual filling the container, the wall outlet for a gas or liquid piped in from a remote reservoir, and containers in similar situations must still be identified. Any labeling method can be used which enables employees and visitors from other agencies such as the fire department to identify the chemical and the hazards. This could be tags, placards or signs identifying the materials and their hazards, color or numeric codes or room diagrams identifying locations of the chemicals and hazards, or other readily observable labeling method.

For peroxide-forming chemicals, such as those listed in Section 2 of the UW Laboratory Safety Manual or those with a material safety data sheet (MSDS) which states the chemical can form peroxides, the container should be labeled with the UoW 1716 label shown at the right, and indicate such information as the date the original container was first opened. These labels are available at the Chemistry Stockroom or through

If a specified “Chemical of Interest” per US Department of Homeland Security is procured (listed below), a label as shown at the left must be attached to the container to remind workers of special requirements.

Chemicals of interest which must be labeled (and their CAS numbers) are:

Acetone cyanohydrin, stabilized (75-86-5)Magnesium phosphide (12057-74-8)
Aluminum phosphide (20859-73-8)Methyldichlorosilane (75-54-7)
Boron tribromide (10294-33-4)Phosphorus oxychloride (10025-87-3)
Bromine pentafluoride (7789-30-2)Phosphorus pentasulfide (1314-80-3)
Bromine trifluoride (7787-71-5)Phosphorus trichloride (7719-12-2)
Calcium phosphide (1305-99-3)Potassium phosphide (20770-41-6)
Chlorine dioxide (10049-04-4)Sodium phosphide (12058-85-4)
Chloroacetyl chloride (79-04-9)Strontium phosphide (12504-16-4)
Chlorosulfonic acid (7790-94-5)Sulfuryl chloride (7791-25-5)
Lithium amide (7782-89-0)Titanium tetrachloride (7550-45-0)
Lithium nitride (26134-62-3)Trichlorosilane (10025-78-2)

Rooms where hazardous materials are stored or used in quantities that exceed certain thresholds ("H" occupancy as defined in the International Fire Code), and rooms dedicated to storing hazardous materials, must be posted with a National Fire Protection Association (NFPA) diamond sign (NFPA Standard 704) on all doors. Call 206-543-0465 for further information and signs. The Seattle Fire Department now requires these signs on all new or renovated laboratories in Seattle and EH&S will post these signs. Explanatory material of the codes used on the NFPA sign is shown below.

Hazard:Fire HazardHealth HazardReactivity
Location:Top QuadrantLeft QuadrantRight Quadrant
RatingDescription of Numeric Rating
4Flash Point <73°F,
Boiling Point <100°F
DeadlyMay Detonate
3Flash Point <73°F and
Boiling Point ≥100°F, or
Flash Point 73°F - 100°F
Extreme DangerShock and heat may detonate
2Flash Point >100°F and ≤200°FHazardousViolent chemical change
1Flash Point ≥200°FSlightly HazardousUnstable if heated
0Will not burnNormal MaterialStable

The bottom diamond segment is white, with any specific hazard codes printed in it. These specific hazards include OX (oxidizers), ACID (acids), ALK (alkali materials), COR (corrosive materials), and W (use no water).

Piping and tubing containing hazardous chemicals should be identified in some manner such that all employees can identify the pipe’s contents. Tags or signs on the pipes/tubing or a room diagram showing the runs should be used in preference to "word of mouth".

Chemicals produced by UW entities and put into commerce may have specific labeling requirements beyond the scope of this guidance manual. These materials and their labeling requirements include:

  • Pesticides (as defined in the Federal Insecticide, Fungicide and Rodenticide Act - 7 USC 136 et seq. and regulations issued by the EPA),
  • Toxic chemicals and mixtures (as defined in the Toxic Substances Control Act - 136 USC 2601 et seq. and requirements issued by the EPA),
  • Foods, food additives, color additives, drugs, cosmetics, or medical/veterinary devices or products including materials intended as ingredients (such as flavors or fragrances) (as defined in the Federal Food, Drug, and Cosmetic Act - 21 USC 301 et seq. or the Virus-Serum Toxin Act of 1913 - 21 USC 151 et seq. and regulations issued by the Food and Drug Administration or the Department of Agriculture),
  • Distilled spirits (beverage alcohols) wine or malt beverage for nonindustrial use (as defined in the Federal Alcohol Administration Act - 27 USC 201 et seq. and regulations issued by the Bureau of Alcohol, Tobacco, and Firearms),
  • Consumer products or hazardous substances (as defined in the Consumer Product Safety Act - 15 USC 2051 et seq. and the Federal Hazardous Substance Act - 15 USC 1261 et seq. and regulations issued by the Consumer Product Safety Commission), and
  • Agricultural or vegetable seeds treated with pesticides (as defined in the Federal Seed Act - 7 USC 1551 et seq. and requirements issued by the Department of Agriculture).

If a chemical is synthesized and sent to another institution, an MSDS or SDS and container label must be generated. See Section 9. Providing an MSDS/SDS for a UW Synthesized Chemical.

Hazardous waste is exempt from the Chemical Hazard Communication Program and inventory requirements in MyChem, but label requirements are mandated in other UW program documents and personnel handling hazardous wastes must be trained concerning potential hazards and necessary precautions. Any container re-used to hold waste must be appropriate for that waste. Labeling of hazardous waste containers should be in accordance with the instructions on the EH&S Hazardous Waste Web Page.

If you have questions about container labeling, contact EH&S at 206-543-7388.