Several months ago I posted an article OSHA publishes DRAFT “Process Safety Management for Small Business Compliance” and how it offered some guidance on how facilities could disperse their inventories of Highly Hazardous Chemicals (HHC) and stay out of or get out of PSM. I have received many e-mails questioning the validity of the material in the DRAFT publication “Process Safety Management for Small Business Compliance” and asking how reliable the instructions are seeing how it was a DRAFT publication. But long before OSHA published their DRAFT document, they offered up the same advice in a much more “official” document…
On September 13, 1994, OSHA published their OSHA Instruction CPL 2-2.45A CH-1 and in this document OSHA offers up some sound advice regarding “dispersal of inventory”. (emphasis by me)
(a)(1)(i) and (b) Covered process – dispersal of inventory
Can an employer who keeps threshold quantities of highly hazardous chemicals listed in Appendix A to 29 CFR 1910.119, such as ammonia, separated into smaller lots and used and stored in separate systems or locations, be exempt from the requirements of the PSM standard?
From a storage standpoint, the 1910.119 standard would NOT apply to an employer who segregates his inventory by dispersing storage of highly hazardous chemicals, such as ammonia, in amounts which do not exceed the threshold quantity so that a release from ONE storage area would NOT contribute to or cause a release from others around the workplace. Additionally, an employer could reduce his on-site inventory of highly hazardous chemicals by ordering more frequent, smaller shipments so that they do NOT exceed the threshold quantities set forth in the PSM Standard. The PSM standard’s non-mandatory Appendix C suggests that, if reduced inventory of highly hazardous chemicals is not feasible, an employer might consider dispersing inventory to several locations on-site.
When are such materials to be considered part of a single process?
Under the definition of “process” provided at 29 CFR 1910.119(b), any group of vessels which are interconnected and separate vessels which are located such that a highly hazardous chemical could be involved in a potential release shall be considered a single process. Inventories of highly hazardous chemicals would NOT be considered to be adequately dispersed if the storage vessels are connected with OR in proximity to a covered process such that they could be involved in a potential release.
What evaluation techniques are appropriate to determine adequate separation distances?
OSHA has not developed, nor is it aware of, any standard evaluation technique to determine adequate distances to separate chemical inventories. If an employer chooses to disperse highly hazardous chemicals on-site, the separation distances would have to be determined on a case-by-case basis, considering such factors as:
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- the nature of the chemicals AND covered processes,
- total inventories,
- threshold quantities of pertinent chemicals, and
- facility layout