KH Workplace Update

Date: Feb 14, 2012


By Lawrence P. Halprin

When OSHA recently placed its combustible dust (CD) rulemaking initiative into the undetermined, long-term actions category, many people apparently concluded that OSHA was giving it a lower priority and that any further regulation of CD was on an indefinite hold. Clearly, that is not the situation. OSHA's regulation of combustible dust will be substantially affected by the pending GHS Amendment to the OSHA HazCom Standard (HCS), the pending OSHA Walking-Working Surfaces and Fall Protection Rulemaking, the ongoing OSHA Injury and Illness Prevention Program Rule initiative, and the ongoing development and revision of CD standards by the National Fire Protection Association (NFPA).

The GHS Amendment to the Hazard Communication Standard

Apparently, as submitted to OMB for review, the GHS Amendment to the HCS would include a controversial "unclassified hazards" category covering combustible dust, without even providing a definition of combustible dust. There is a sound legal argument that CD is not currently covered by the HCS. Whether that category will remain in the final rule and whether the final rule will cover combustible dust should be known by February 24, when OMB is expected to complete its review.

The General Housekeeping Rule

Also pending, as part of the OSHA Walking-Working Surfaces and Fall Protection rulemaking, is the language and legal status of the general housekeeping requirement that has been used by OSHA to cite employers for allegedly excessive CD accumulations. There is a sound legal argument that the housekeeping provision was improperly adopted by OSHA in 1972. It was part of a national consensus standard (NCS) with a scope provision limited to industrial hygiene issues. OSHA substantively changed the language of the NCS by adopting it without the scope provision. Given that OSHA never developed the legal foundation for the expanded scope of the housekeeping rule, and the rulemaking record is now closed, OSHA's path forward on that provision is far from clear. It may have to fall back on the General Duty Clause to cite excessive dust accumulations.

The I2P2 Initiative

Finally, on the regulatory front, OSHA is aggressively pursuing adoption of an all-encompassing Injury and Illness Prevention Program Rule (a/k/a the I2P2 Rule or the IIPP Rule), which would address every hazard covered by either an existing OSHA standard or the General Duty Clause. If OSHA is successful, a broadly interpreted I2P2 Rule could eliminate the need for any further OSHA rulemakings. Without having to show technical and economic feasibility on an industry-wide basis, OSHA would attempt to rely on the I2P2 rule to, for example, impose on employers, all of the overly burdensome and unnecessary requirements contained in: (1) the ergonomics program standard rejected by a bi-partisan Congress in 2001 (2) the comprehensive crystalline silica standard that has been on hold at OMB for almost a year; and (3) the current and future NFPA CD standards.

Evolving NFPA Combustible Dust Standards

In its October 21, 2009 Advance Notice of Proposed Rulemaking for CD, OSHA indicated that, contrary to the assertions of the CSB, the content of the five existing NFPA CD standards was valuable, but was not presented in a consistent or integrated form that could be incorporated into an OSHA standard. In response, NFPA Staff recommended that NFPA approve a proposal to combine the five NFPA CD standards -- NFPA 61 (agriculture and food processing), NFPA 484 (metal industry dust), NFPA 654 (pulp, paper and everything else not covered by one of the other standards), NFPA 655 (sulfur processing dust), and NFPA 664 (wood processing dust) -- into a single document.

It soon became apparent that the lead NFPA CD committee, responsible for NFPA 654 and NFPA 655, was moving in the direction of a far more conservative approach to the control of combustible dust, which was not supported by the majority of the members of NFPA 61 and NFPA 664. Recognizing the difficulty of reconciling the conflicting views of the committees, the NFPA Standards Council approved a plan to create a new CD Technical Committee that, essentially using NFPA 654 as a starting point, would develop and issue a new core CD standard (NFPA 652) to cover the basic requirements for controlling CD. NFPA 652 would supersede the corresponding provisions in the five existing CD standards, which would eventually be harmonized with NFPA 652 or eliminated under the direction of a new CD Technical Correlating Committee (TCC). NFPA 652 is scheduled to be completed in 2012 and adopted in the Spring of 2013, subject to the appeals process that could extend the adoption date, but probably not beyond the Summer of 2013. Depending on the status of the I2P2 initiative, OSHA could then decide whether to initiate a CD rulemaking or essentially enforce NFPA 652 through its existing standards and the General Duty Clause.

The ongoing development of NFPA 652 may be the last opportunity to force a re-examination of what appears to be a steady movement toward a zero-risk approach to the regulation of CD. For example, it appears that all of the serious CD incidents reported by the CSB and OSHA involved facilities with inches of accumulated combustible dust. However, consistent with the tentative interim amendment (TIA 06-1) to NFPA 654 adopted in 2011, it appears that the new version of NFPA 654 will "require" site operators to identify and take into account all "non-separated" dust layers of more than 1/64 inch. Eventually, if not in its initial version, NFPA 652 can be expected to incorporate the shift, established by TIA 06-1, from a layer-based method to a far more restrictive and far more complicated mass/volume-based method for determining when (at least under the specification-based approach), dust accumulations will be deemed to pose a CD deflagration (flash fire or explosion) hazard.

Prior to TIA 06-1, the specification-based provisions of NFPA 654-2006 specified the measures that were "required" when a combustible dust hazard was present, but did not specify the conditions that presented a combustible dust hazard. Annex D to NFPA 654 established "non-mandatory" guidelines indicating that routine cleaning should be performed to prevent accumulations of CD, with a bulk density of 75 lbs/ft3, in layers of 1/32 inch ("the Layer Depth Criterion") or more over more than five percent of a floor footprint area (up to a maximum of 1000 ft2). Reflecting a determination that the magnitude of the hazard is based on the mass of fuel (CD) present rather than its layer thickness, NFPA 654-2006 contained a linear Bulk Density Equation that permits the "Layer Depth Criterion" to be adjusted[1] to reflect the actual bulk density of the CD. Our understanding is that many organizations had been using the 5% coverage area as a rule of thumb for all areas at or above the Layer Depth Criterion without regard to the actual thickness of the dust layer. The NFPA 654 Committee determined that this approach was not adequately protective because it did not accurately reflect the existence or magnitude of the combustible dust hazard, which it determined was related to the mass of CD and not the layer thickness. In addition, OSHA enforcement staff asserted that the Layer Depth Criterion, as modified by the Bulk Density Equation, was not adequately protective because, under idealized (and entirely unrealistic conditions) conditions, a CD layer as thick as the Layer Depth Criterion could create an airborne cloud 3 to 6 times the minimum explosible concentration.

In light of those considerations, the NFPA 654 Committee adopted TIA 06-1, which, despite what it seems to say, eliminates any consideration of layer thickness in determining whether a CD deflagration hazard is present, except that a layer of 1/64 inch or less can be ignored. Under TIA 06-1, a dust deflagration hazard is deemed to exist where the total volume of dust accumulations is greater than the Layer Depth Criterion multiplied by 5% of the footprint area. (The alternative layer test is a mirage because the volume formulation will always be as stringent or more stringent and supersede the layer formulation.) Unless the regulated community demonstrates that the approach in TIA 06-1 is invalid (or at least not universally applicable for all CD) and/or infeasible, it seems likely that it will (at least eventually, if not in the 2013 edition) be incorporated into NFPA 652.

NFPA 652 will supersede all other NFPA CD standards (such as NFPA 61 covering the food and agriculture industries), and presumably would be used by OSHA to establish the presence of a CD deflagration hazard. The existence of the OSHA Grain Handling Standard may not shelter the grain industry from this development. OSHA regulation 29 CFR 1910.5(f) generally provides that an employer in compliance with an OSHA standard is deemed to be in compliance with the requirements of the General Duty Clause to the extent the condition, practice, means, method, operation, or process is covered by the standard. In UAW v. General Dynamics Land Systems,[2] the D.C. Circuit held that this provision was invalid to the extent that the applicable standard provided a lesser degree of protection than would be provided by the General Duty Clause. Given the aggressive enforcement posture taken by OSHA in seeking enterprise-wide Review Commission orders imposing abatement measures applicable to sites it has never inspected, we would not put it past the agency to test the limits of the holding in General Dynamics Land Systems.

If you have any questions or we may be of assistance regarding these issues, please contact Lawrence P. Halprin (halprin@khlaw.com or 202.434.4177), Peter L. de la Cruz (delacruz@khlaw.com or 202.434.4141), or David G. Sarvadi (sarvadi@khlaw.com or 202.434.4249).

[1] The adjustment is a simple linear equation. The adjusted Layer Depth Criterion is equal to 1/32 inch multiplied by a factor equal to 75 lbs/ft3 divided by the bulk density of the actual material. For example, the Layer Depth Criterion for dust with a bulk density of 15 lb/ft3 would be 5/32 inch. [1/32" x (75 lb per ft / 15 lb per ft3)].

[2] 815 F.2d 1570 (D.C. Cir. 1987).