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Hazard Not Otherwise Classified (HNOC)

What Does Hazard Not Otherwise Classified (HNOC) Mean?

A hazard not otherwise classified (HNOC) refers to a workplace hazard that is not covered by the Globally Harmonized System (GHS) of hazard classification. A chemical product containing an HNOC must be addressed in Section 2 of the safety data sheet (SDS). Though not mandatory, it may also be included under the supplemental information section of the product label.

Safeopedia Explains Hazard Not Otherwise Classified (HNOC)

The 2012 version of the Occupational Safety and Health Administration (OSHA) Hazard Communication Standard 29 CFR 1910.1200 paragraph (c) (HCS 2012), defines an HNOC as “an adverse physical or health effect identified through evaluation of scientific evidence during the classification process that does not meet the specified criteria for the physical and health hazard classes addressed in this section."

This includes hazards that are deemed a low risk, falling below the threshold for inclusion in a particular hazard class, as well as hazard categories that are part of the GHS but not used by OSHA.

Products with HNOCs

Hazards not otherwise classified include hazards that are not yet defined under regulations. This does not absolve employers of responsibility - HNOCs are hazards and they must be treated as such, even if they do nmot fit in the official hazard classificatiomn.

Chemical products that pose hazards that meet OSHA's definition of an HNOC should be addressed during employee training.

The SDS should list any HNOC related to a given product. Unlike classified hazards, however, it does not need to be represented with the elements typically dictated by the Hazard Classification System (HCS). Since there are no signal words or pictograms for HNOCs, none are assigned when labeling.

Supplemental information can be added and does not need to be separated from the required information on the label. However, it should not impede the identification of required HazCom label information such as signal words, and hazard and precautionary statements.

HNOCs Under Canada’s WHMIS

Canada’s national hazard communication standard, the Workplace Hazardous Materials Information System (WHMIS) uses a similar concept. However, unlike OSHA, WHMIS groups these hazards under two categories:

  • Physical Hazards Not Otherwise Classified (PHNOC)
  • Health Hazards Not Otherwise Classified (HHNOC)

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