On December 27, 2013, OSHA quietly issued a memorandum to all Regional Administrators providing compliance guidance to Compliance Safety & Health Officers (CSHO) for inspections of manufacturers and importers under the revised Hazard Communication Standard.  Specifically, the guidance is meant to provide CSHOs with criteria for determining whether classifiers (manufacturers and importers) have appropriately classified “combustible dust.”

The revisions to the Hazard Communication Standard, 29 C.F.R. §1910. 1200, included a revised definition for “hazardous chemical.” The new definition defines a hazardous chemical as:

  any chemical which is classified as a physical hazard or a health hazard, a simple asphyxiant, combustible dust, pyrophoric gas, or hazard not otherwise classified.

Although there is currently no OSHA standard regulating combustible dust, OSHA has included combustible dust as a hazardous chemical. This means that all manufacturers and importers (classifiers) will now need to determine and appropriately classify their products as combustible dust. 

How exactly does OSHA anticipate that classifiers will do this?  In this recent memorandum, OSHA indicates that “[t]he classifier must consider not only the hazards of the chemical in the form it is shipped, but also consider the hazards that arise under normal conditions of use and foreseeable emergencies.” The memorandum instructs CSHOs when conducting inspections to determine if the classifier has used one or more of the following approaches to determine if such hazards exist:

  •  Laboratory Testing.  Classifiers can rely on screening tests, such as ASTM E1226 and E1515 to establish whether a material is a combustible dust.  If results of accepted tests indicate the material is combustible then according to OSHA is should be classified based on those results.  Additionally, OSHA seems to suggest that if a material would be considered combustible under OSHA’s combustible dust National Emphasis Program (NEP), which is any dust that has a Kst greater than zero, then it should be classified as combustible. 
  • Published Test Results.  The classifier may rely on published data, such as NFPA 61, 68 and 499 which lists test results for various materials.
  • Dust Particle Size.  In the absence of published test data, OSHA suggests that classifiers can rely on particle size, if such information is available. “If the material will burn and contains a sufficient concentration of particles 420 microns or smaller to create a fire or deflagration hazard, it should be classified as a combustible dust.”

 In addition, OSHA asserts that any product that has been involved in a deflagration or dust explosion event should be classified as a combustible dust.

Where a classifier does not use one of these approaches or elects not to classify a material as combustible despite the use of one or more of these approaches then the classifier will have to prove to OSHA why the data was discarded and the material was otherwise classified.  In short, the classifier will have an uphill battle to prove to a CSHO why the material is not combustible.

Manufacturers and importers have until June 15, 2015 to review current products and determine whether any products must now be classified as a combustible dust and if so, must classify these products as such on Safety Data Sheets (SDS).

OSHA’s memorandum can be found here.