OSHA Letter of Interpretation Guide – GHS and HazCom

As we move toward full adoption of GHS in the United States, OSHA continues to issue letters of interpretation (LOI) to clear up grey areas and answer questions posed by stakeholders. MSDSonline regularly provides updates on these letters, and gives readers actionable information that companies can use to prepare for new guidance in enforcement policy that might result from these interpretations. In that connection, here is a review of GHS-related clarifications and qualifications that OSHA has made via LOI’s since the start of 2014.

Note: OSHA’s LOI’s tend to use “HCS 2012” instead of “GHS” so we have largely reproduced that language here. But keep in mind that these terms both represent OSHA’s adoption of the third revision of the U.N.’s Globally Harmonized System of Classification and Labelling of Chemicals, commonly known as GHS.


Ink Cartridge HazCom Questions — March 27, 2015

This LOI clarifies a number of questions relating to the labeling of ink and shipped ink cartridges, but some of the clarifications may be applicable to other products/substances.

Responding to a series of very specific questions, OSHA clarifies/reiterates that:

  • Goods being shipped international into the U.S. — in this case, printer cartridges — must still be labeled as Category 3 or Category 4 flammable liquids when this is indicated by their OSHA-prescribed performance on flash point tests, even if they are not classified as “flammable liquids” under the United Nations’ Recommendations on the Transport of Dangerous Goods.
  • Labels and SDSs must contain information reflecting a classification of Specific Target Organ Toxicity — Repeated Exposure (STOT-RE) if ink in an ink cartridge has been so classified, even if:
    • The route of exposure if oral
    • You believe that repeated exposure through ingestion is improbable
    • You believe that no risk is posed to your workers 
    • “The ink cartridge and printer employ design features engineered to prevent worker exposure during most stages of the product life cycle under normal conditions”
  • Hazards associated with cartridge ink need only be communicated to the employees that might be directly subject to exposure to that ink.
  • It is not acceptable to communicate ink hazards only in an employee handbook, and the containers of ink must be labeled in accordance with HCS 2012.



Multi-Country Labels and Downstream Processing Hazards — February 10, 2015

This letter addresses two labeling scenarios. In the first, a manufacturer that ships globally would like to include chemical hazard labeling for the US, EU, and China on all packaging, in “clearly marked separate boxes.” OSHA responds that it may be technically possible for the manufacturer to do this and remain compliant, but strongly cautions that “if the other countries have hazard classification information that contradicts or casts doubt on the HCS 2012 information, it is not permitted to be on the label.” (OSHA also advises consulting a previous LOI on the topic.)

In the second scenario, OSHA responds to a case in which manufacturer makes a substance that is not hazardous in shipped form, but which becomes hazardous when processed downstream, and wonders if the shipped label must reflect this hazard. OSHA says yes. The LOI clarifies that the manufacturer “must consider the hazards of a chemical during normal conditions of use or in a foreseeable emergency” and says that hazards related to normal processing must be considered in conducting the hazard classification.



Crystalline Silica Classification and Labeling—February 10, 2015

This LOI provides a number of clarifications related to concerns around labeling and classifying products containing crystalline silica. The letter deals with when and how testing for hazard category and carcinogenicity are required. It also clarifies that when classifying a mixture containing crystalline silica, the classification is based on the total amount of crystalline silica by weight or volume of the mixture—not just the amount of respirable silica in the bulk product—because OSHA says the other silica “can become respirable during normal conditions of use or foreseeable emergencies.”  The letter also clarifies criteria for “scientifically validated” chemical testing methods. In addition, it makes clarifications around:

  • Ready-to-apply pastes containing small percentages of crystalline silica
  • Potential for crystalline silica exposure during sanding
  • The relationship of exposure testing to hazard classification



Application of GHS HazCom to Truckers Hauling EPA-Exempt Waste — December 23, 2014

The EPA’s Resource Conservation and Recovery Act (RCRA) exempts certain waste materials often hauled by truckers servicing drilling sites from regulation. This LOI responds to questions from trucking companies wondering of materials granted this exemption by the EPA will be subject to regulation under HCS 2012. OSHA responds that it’s true that the HCS (both 1994 and 2012) does not apply to certain “hazardous waste as such term is defined by the Solid Waste Disposal Act, as amended by the Resource Conservation and Recovery Act of 1976, as amended (42 U.S.C. 6901 et seq.), when subject to regulations issued under that Act by the Environmental Protection Agency.”  But OSHA also cautions that while some waste from drilling sites is likely to fall into this category, some may not fall into this category and will still be subject to HCS regulation. The letter seems to encourage trucking companies to investigate the potential exemption status of what they’re hauling on a case-by-case basis, and provides links to guidance documents where users can look up both exempt and non-exempt waste products.



SDS Clarifications Related to Concentrated Substances and Tandem Packaging — December 23, 2014

This LOI makes two clarifications related to SDSs:

  • When a manufacturer makes a concentrated product (intending that the end user will add water to it before using it), the manufacturer typically only needs to include an SDS for the concentrated form of the product. However, if they know that the intended future dilution will produce a new hazard, then that must be noted in Section 10 of the SDS. And if the intended future dilution will somehow produce a new chemical, then a unique SDS would also need to be supplied for that eventuality.
  • In a case where several hazardous chemicals are packaged together in “separate inner container[s]” or “in a distinct compartment of a single container,” a separate SDS is still required for each separate hazardous chemical in the shipment. In addition, if the manufacturer intends the co-packaged chemicals to be used together and that use creates a new hazard, then those hazards must be noted in Section 10 of the SDS.



Application of GHS HazCom to Railroad Crew Workers Doing Hazmat — December 23, 2014

This LOI addresses the question of whether or not updated, HCS 2012 rules and training requirements will apply to railroad train crew members engaged in hazardous materials (hazmat) work. In the letter, OSHA points out that while this is an area usually governed by the Department of Transportation (DOT): “DOT rules on hazmat transportation do not preempt OSHA from enforcing occupational safety and health standards regarding hazmat.” Thus, OSHA says, yes, it can and may enforce for GHS compliance among railroad crews engaged in hazmat work.



Unused Pictogram Borders — December 23, 2014

This letter clarifies that in situations where an employer may have purchased label stock with pre-printed red diamond borders, it is not compliant to print the words “Intentionally Blank” or “No GHS Pictogram” inside the diamond when there is no hazard to be represented. Instead, in a case like this, OSHA says the unused red diamond borders on the stock must be completely “blacked out,” effaced, removed, or covered with a black diamond sticker.



Visibility of GHS Elements on Shipped Container Labels — November 27, 2014

In this LOI, OSHA clarifies that although there are six required elements on shipped container labels (product identifier, signal word, hazard statement, pictogram, precautionary statement, and name/address of the manufacturer), it is not the case that all six are required to appear in the same immediate “field of view.” Instead, just three elements—signal word, hazard statement(s), and pictograms(s)—are required to be immediately viewable. In the case of a small label, OSHA says it is allowable that the remaining three elements could be contained in a “fold-back label, pull-out label” or similar device.



Combining Hazard Statements — November 10, 2014

This LOI says that chemical manufactures and importers may combine redundant hazard statements on labels to shorten text, if doing so will preserve all salient safety information. OSHA gives the example of a manufacturer of a substance requiring the hazard statements “Causes severe skin burns and eye damage” and “Causes serious eye damage.” According to the example, the manufacturer could omit the second hazard statement because that information is contained in the first.



Secondary Container Labeling in Labs — November 10, 2014

This LOI addresses labeling secondary containers in research and academic labs. OSHA points out that some of these labs are covered under the Laboratory standard (29 CFR 1910.1450) and not by HCS 2012; these tend to be facilities using comparatively “small amount of a limited variety of chemicals.” This LOI says that labs not covered by the Laboratory standard will be subject to HCS 2012 labeling requirements, but that OSHA “does not have a specific labeling requirement for secondary containers of hazardous chemicals in a covered laboratory.” The LOI also clarifies that employers are not required to re-label containers of hazardous chemicals in their labs (or other facilities) that were shipped prior to June 1, 2015. However, it notes that employers should educate workers on the difference between HCS 2012 and HCS 1994 labeling they might see in their workplace.



Consumer Product Safety Commission Label Elements — May 12, 2014

This letter addresses labeling concerns of manufacturers making products that may require label elements prescribed by the Consumer Product Safety Commission (CPSC) on their shipped containers. This LOI points out that OSHA exempts products from HCS 2012 labeling requirements when they fall under the labeling requirements of the Consumer Product Safety Act and the Federal Hazardous Substances Act. However, it also notes that manufacturers seeking to add additional information on a label may do so, but it must not “contradict or cast doubt” on any of the OSHA-required hazard information. (The letter provides examples of things that might do this.) The letter also examines a hypothetical situation where OSHA and the CPSC differ on hazard statements for flammables, and shows that a single-label solution might not be possible in this case.

Note: There is some ambiguity about the answers in this letter, and persons desiring more information and clarity are encouraged to contact their local OSHA representative.



Organ Toxicity Under GHS — March 4, 2014

This LOI provides information around categorizing substances (as Category 1 or Category 2) in the Single Target Organ Toxicity (STOT) single exposure (SE) or repeat exposure (RE) classification under HCS 2012. It provides information around the specific mixture percentages needed to meet certain classification criteria.



Petroleum Streams Under GHS — March 4, 2014

This LOI provides clarifications around substances derived from crude oil, and to crude oil itself. It provides specific guidance for classifying the health hazards of petroleum streams under HCS 2012, and what to do in extenuating circumstances such as when test data may not be available for a stream, and/or when substantially similar streams are not available for reference. The LOI also provides information about creating SDSs for petroleum streams.



Combustible Dust Under GHS — March 4, 2014

This LOI provides clarifications around the Combustible Dust hazard under HCS 2012. It reviews:

  • The modification of the required hazard statement for Combustible Dust and example scenarios in which possible alternative phrasing of the hazard statement would be acceptable
  • Safety Data Sheet requirements for substances containing or potentially containing combustible dust under a variety of scenarios
  • Requirements for labels on shipped containers
  • Requirements for workplace labels




HNOC Under GHS — March 4, 2014

This LOI provides guidance on how to apply the requirements for Hazards Not Otherwise Classified (HNOC) classification under HCS 2012. It reminds users of the definition of an HNOC, and of cases when the classification ought to be applied. It provides source material for conducting classifications, pointing readers to sections of the OSH Act covering adverse physical and health effects. It also touches on when substances should not be classified as HNOC’s, and why. (For example, water should not be classified as an HNOC, even though “an employee might be scalded by contact with boiling water or [. . .] might contract hypothermia by being immersed in cold water for a long period of time.”)