Topic Hubs

WSPPN Maintains These Topic Hubs

Auto Repair
We also maintain topical information about Fleets.

News Articles About These Topic Hubs:

Hospitality News
Auto Repair News
Fleets News

Browse by Keyword

Safer Chemical Alternatives: Identifying Chemical Hazards - Labeling Systems
Table of Contents
Background and Overview
Reasons for Action
Identifying Chemical Hazards - Labeling Systems
Related Efforts, Tools, and Resources
Case Studies and Examples
Where to Go for Help
Complete List of Links

Essential Links:

HMIS Labeling System Guidebooks and Implementation Manuals
Free downloads of the Hazardous Materials Identification System (HMIS) guidance for use and implemen...

OSHA Regulations and Official Inspection Guidelines
Provides information on how OSHA laws regulate communication of hazard communication and MSDS inform...

OSHA Small Business Handbook
This handbook helps small business employers meet the legal requirements of OSHA regulations and pas...

Reducing industrial emissions of hazardous chemicals is good for the environment and good for business. Reducing hazardous chemical use can reduce costs of waste handling and regulatory compliance. In addition, employees must be protected from chemical hazards. Federal laws state that workers have both a need and a right to know the hazards of chemicals they may be exposed to in the workplace. Identifying and understanding the hazards of workplace chemicals can help businesses prioritize efforts to minimize or eliminate the use of hazardous chemicals.

Minimum standards for workplace information on chemical hazards are governed by the Occupational Safety & Health Administration’s (OSHA) Hazard Communication Standard (HCS). The HCS establishes requirements for businesses to provide information and training on chemical hazards and the means by which workers can be protected. Requirements include labeling of chemical products and the provision of Material Safety Data Sheets (MSDS) to identify specific hazards of individual chemical ingredients. In OSHA's transition to adoption of the Globally Harmonized System (GHS), a system that is being rolled out internationally starting in 2013, OSHA is adopting GHS labeling and changing from the historical MSDS to Safety Data Sheets, both of which will be standardized across the world.

Hazardous Chemical Labeling Systems

Product labels typically provide the first line of defense for identifying chemical hazards.

OSHA requires that containers be labeled, marked or tagged with the identity of any hazardous chemical and some general information about the hazards that these chemicals present. In the GHS system, these will be communicated through words and pictograms. During the phase-in period of GHS, employers would be required to be in compliance with either the existing HCS or the revised HCS, or both. OSHA recognizes that hazard communication programs will go through a period of time where labels and SDSs under both standards will be present in the workplace. This will be considered acceptable, and employers are not required to maintain two sets of labels and SDSs for compliance purposes. The GHS system will be phased-in with milestones and training requirements occuring from December of 2013 through final and complete adoption as of June 2016. Further details are available from OSHA.

Historically, OSHA has allowed flexibility in labeling as long as a hazard communication program is effective overall. A few alternative labeling systems were acceptable to help meet requirements: The National Fire Protection Association (NFPA) 704 Hazard Rating and the Hazardous Material Identification System (HMIS). The differences in the two systems are breifly described below.

As GHS is implemented, an OSHA brief (February 2013) states that employers may continue to use rating systems such as NFPA and HMIS as long as they are consistent with the requirements of the Hazard Communication Standard as adapted for GHS.

NFPA provides a common labeling category is required for transportation of dangerous goods and emergency response. In the case of fire or chemical spills, emergency responders need to understand short-term exposure risks to be protected. Furthermore, the appropriate emergency response may vary depending on which chemicals are present in the workplace. These types of labels, for example, theNFPA Diamond (Standard 704), deal with acute hazards and are not intended to reflect occupational risks or chronic exposures from environmental releases.

When considering occupational or chronic environmental exposures, the Hazardous Materials Identification System (HMIS) developed by the National Paint and Coatings Association (now the American Coatings Association) has been historically used. The HMIS label includes acute and chronic health effects and personal protective equipment (PPE) recommendations. While not directly focused on environmental releases, the broader set of hazards included in HMIS, as compared to NFPA, offer a hint of the potential risk of environmental damage.

The GHS, HMIS, NFPA, labelling systems are described below.

Globally Harmonized System - Label Elements

The standardized label elements of the GHS are:

  • Symbols (hazard pictograms): Convey health, physical and environmental hazard information, assigned to a GHS hazard class and category.
  • Signal Words: "Danger" or "Warning" are used to emphasize hazards and indicate the relative level of severity of the hazard, assigned to a GHS hazard class and category.
  • Hazard Statements: Standard phrases assigned to a hazard class and category that describe the nature of the hazard.

The symbols, signal words, and hazard statements have all been standardized and assigned to specific hazard categories and classes, as appropriate. This approach makes it easier for countries to implement the system and should make it easier for companies to comply with regulations based on the GHS.

A great explanation of the system, with examples is available online in Section 4.3 of OSHA's Guide to The Globally Harmonized System of Classification and Labelling of ChemicalsSection 4.3 of OSHA's Guide to The Globally Harmonized System of Classification and Labelling of Chemicals (GHS). All of the prescribed symbols, signal words, and hazard statements are readily found in Annex 1 of the GHS "Purple Book", the official document published by the United Nations for use internationally.

NFPA 704 - National Fire Protection Association

The NFPA 704 hazard identification system label is easily recognized by its distinctive diamond shape. The main NFPA diamond is composed of four sub-diamonds. Each sub-diamond includes a number representing the hazard rating from zero (low) through four (high). A blue diamond indicates “Health”, a red diamond represents “Flammability”, a yellow diamond indicates “Instability,” and a fourth white diamond used to address additional hazard criteria, typically the presence of unusual reactivity with water (critical information for first responders).

When addressing chemical toxicity, the most relevant NFPA information is in the blue health hazard diamond. The NFPA describes a health hazard as “the capability of a material to cause personal injury to due to contact with or entry into the body via inhalation, skin contact, eye contact or ingestion.” The numeric levels of human health hazard include:

    4 - Materials that, under emergency conditions, can be lethal

    3 - Materials that, under emergency conditions, can cause serious or permanent injury

    2 - Materials that, under emergency conditions, can cause temporary incapacitation or residual injury

    1 - Materials that, under emergency conditions, can cause significant irritation

    0 - Materials that, under emergency conditions, would offer no hazard beyond that of ordinary combustible materials

Unfortunately, there is no easy way for employers or employees to relate these numeric hazard ratings to any specific human health hazard. As mentioned previously, NFPA 704 is intended for emergency use and does not address health hazards from chronic or repeated long-term exposure to hazardous materials. At best, users of chemical products can use these hazard ratings to indicate a rough “level-of-concern,” but they should not be used as a substitute for a detailed consideration of any chemical or chemical product’s safety.

Detailed criteria for applying these numeric hazards levels are provided in an appendix to the NFPA 704 standard (Appendix B – Health Hazard Rating). While not freely available, the NFPA 704 standard is available for purchase from the National Fire Protection Association website. Rating values for some common chemicals can be found at a Michigan State University website.

HMIS - Hazardous Materials Identification System

HMIS labels appear as a rectangle-shaped block of colored bars with numeric hazard ratings. HMIS version III, released in 2002, uses labels with a blue "Health" bar on top, a red "Flammability" bar below that, followed by an orange "Physical Hazard" bar and a white PPE area. The level of hazard is identified by a single number in each hazard area ranging from zero (low hazard) to four (high hazard). Prior to 2002, the HMIS label used a yellow “Reactivity” bar in place of the “Physical Hazard” bar. The HMIS labeling program criteria and information for implementation as part of a full hazard communication program are freely available at the J. J. Keller & Associates website.

The HMIS label was developed primarily to address occupational safety. The “Health” numeric hazard rating is similar to the NFPA system:

    4 - Severe hazard: life-threatening; major or permanent damage may result from single or repeated exposures; extremely toxic; irreversible injury may result from brief contact

    3 - Serious hazard: major injury likely unless prompt action is taken and medical treatment given; high level of toxicity; corrosive

    2 - Moderate hazard: temporary or transient injury may occur; prolonged exposure may affect the CNS and lead to apparent intoxication, nausea, headache, dizziness, weakness or fatigue

    1 - Slight hazard: minor reversible injury may occur; may irritate the stomach if swallowed; may defat the skin and exacerbate existing dermatitis;

    0 - Minimal hazard: no significant health risk; no effect anticipated; practically non-toxic; irritation of skin or eyes not anticipated

Each higher level of hazard indicates a roughly ten-fold increase in toxicity. In addition to the numeric rating, the HMIS III label includes a box to indicate the presence or absence of a hazard from chronic exposure. The box should include a slash if no chronic hazard is anticipated.

As with NFPA 704, the five levels of health hazard provide only a rough guide to chemical hazards. The numeric health hazard rating is based on acute toxicity, with the most toxic effect guiding the applied rating. These effects include skin and eye irritation or corrosion, and toxicity via inhalation, oral or dermal routes (exposure via lungs, mouth and skin). For many occupational environments, chronic exposures to chemicals are common. Effects from long-term exposure might include cancer or harm to specific body organs such as the liver or lungs (target organs). Chronic effects show only as an asterisk (*) in the HMIS system and do not affect the numeric health hazard rating.

A quick guide to the HMIS system can be found at the IPLI website. Detailed guidance can be found in the HMIS Chemical Ratings Guide on the J. J. Keller website. Rating values for many chemicals and supporting data can be found in the HMIS III guidance documents.

Other Labeling Systems

OSHA will soon begin implementing a revision to chemical labeling requirements to conform to provisions of the Globally Harmonized System (GHS) for classification and labeling. Information on the US implementation of GHS should become available in 2012.

Lab Safety Supply company offers labels under their own Hazardous Material Identification Guide (HMIG). The HMIG system closely resembles the HMIS system, however, the Lab Safety Supply website offers few specifics on how the rating numbers are generated. As with the HMIS system, PPE suggestions are incorporated on the label.

The American Chemistry Council has developed a label and safety data sheet (SDS) combined standard maintained by the American National Standards Institute as ANSI Z400.1/Z129.1-2010. This standard is a revision and c7onsolidation of two earlier, related standards and contains details on material identity, manufacturer information, hazard classification, emergency information, instructions on what to do if a hazardous situation has occurred information on the prevention of hazardous situations and guidance on other technical information to be included in an SDS. The standard was designed with the OSHA implementation of GHS in mind.

Health Hazard Labels for Some Typical Workplace Chemicals

To illustrate how these systems differ, examine the ratings applied to three common solvents, acetone, methyl ethyl ketone (MEK), and toluene, and a common plasticizer, dibutyl phthalate. Data for the GHS label categories were obtained from various GHS Safety Data Sheets produced by various companies. Data for the HMIS III label were obtained from the J. J. Keller website. Data for NFPA were obtained from the Michigan State University website.

Note that HMIS and NFPA scales move numerically higher with increasing toxicity or health hazard, while GHS ratings move numerically lower with increasing toxicity, i.e., GHS Category 1 reflects the most severe toxicity and 5 the least.

Chemical GHS Health Ratings HMIS Health Ratings NFPA Health Rating
Acetone Specific Organ Toxicity: 3 HMIS Health: 2 + Chronic * NFPA Health: 1
Methyl ethyl ketone Acute Toxicity: 4 HMIS Health: 2 + Chronic * NFPA Health: 1
Toluene Acute Toxicity (oral): 4

Specific Organ Toxicity: 2
HMIS Health: 2 + Chronic * NFPA Health: 2
Dibutyl phthalate Acute Toxicity (oral): 5

Specific Organ Toxicity: 1

Reproductive Toxicity: 2
HMIS Health: 1 NFPA Health: 2

MEK, which is highly toxic to the nervous system, among other hazards, is identified in NFPA as a level 1 rating, notable only in its potential for irritation. This would not sufficiently indicate the risk of day-to-day work exposures to MEK. GHS and HMIS labels also indicate chronic hazards that are not shown or considered in the NFPA system. Acetone has in general lower toxic properties than MEK, but is rated similarly in both systems.

Toluene is very highly toxic to the central nervous system (CNS), but rates only a 2 for health in HMIS and NFPA, suggesting only temporary damage. However, the GHS label shows specific organ toxicity (single exposure) for toluene, reflecting the more significant toxicity to the CNS.

Dibutyl phthalate is known to have kidney and CNS affects, and is widely recognized as toxic to reproduction. This is reflected in the GHS label for specific organ toxicity. However, it only receives a 1 for health in the HMIS III system and includes no indication of the chronic hazard it presents to reproductive health. This suggests that published HMIS III ratings for this chemical have not been updated with the most current human hazard information.


The Topic Hub™ is a product of the Pollution Prevention Resource Exchange (P2Rx)

The Safer Chemical Alternatives Topic Hub™ was developed by:

Contact email:

Hub Last Updated: 5/21/2015