PLEASE NOTE the LOI in which OSHA adopted EPA’s 1% rule was thrown out by the courts so I am NOT 100% sure OSHA can use the 1% rule from EPA in their evaluations of what is a covered process/HHC.
Last week OSHA changed their position in how they will handle “mixtures” of those chemicals listed in 1910.119 Appendix A WITHOUT a concentration percentage listed. OSHA rescinded all prior policy documents, letters of interpretation, and memoranda related to the maximum “commercial grade” or pure (chemical) grade policy in favor of a one (1) percent test similar to that adopted by EPA in regards to their RMP rule (e.g. EPA’s “1% rule”). Yes, using EPA’s “1% Rule” for both PSM and RMP does make things simpler for everyone, but boy-oh-boy does it have some potential challenges for the industry. Let’s examine some of the implications this change could have…
Here is OSHA’s new method of determining applicability for “mixtures”…
In determining whether a process involves a chemical (whether pure or in a mixture) at or above the specified threshold quantities listed in Appendix A, the employer shall calculate:
(a) the total weight of any chemical in the process at a concentration that meets or exceeds the concentration listed for that chemical in Appendix A, and
(b) with respect to chemicals for which NO concentration is specified in Appendix A, the total weight of the chemical in the process at a concentration of one (1) percent or greater. However, the employer needs to NOT include the weight of such chemicals in any portion of the process in which the partial pressure of the chemical in the vapor space under handling or storage conditions is less than 10 millimeters of mercury (mm Hg). The employer shall document this partial pressure determination.
In determining the weight of a chemical present in a mixture, ONLY the weight of the chemical itself, exclusive of any solvent, solution, or carrier is counted.
You may notice that OSHA appears to only mention “toxic mixtures” concentrations in their new position memo. More on this later.
So not only do PSM and RMP have different thresholds for the same chemicals, the two listings of toxins HHC(s) and EHS(s) are different as well. In fact, OSHA’s PSM Appendix A contains over 70 HHCs that EPA’s RMP does NOT cover.
Here are some of these PSM HHCs that are NOT covered by EPA’s RMP rule:
- 107-05-1 – Allyl chloride
- 7790-98-9 – Ammonium Perchlorate
- 7787-36-2 – Ammonium permanganate
- 13863-41-7 – Bromine chloride
- 7789-30-2 – Bromine pentafluoride
- 7787-71-5 – Bromine trifluoride
- 106-96-7 – 3-Bromopropyne [Propargyl Bromide]
- 75-91-2 – Butyl hydroperoxide (tertiary)
- 614-45-9 – Butyl perbenzoate (tertiary)
- 353-50-4 – Carbonyl fluoride
- 9004-70-0 – Cellulose nitrate
- 13637-63-3 – Chlorine pentafluoride
- 7790-91-2 – Chlorine trifluoride
- 97-00-07 – 1-Chloro-2,4-dinitrobenzene
- 96-10-6 – Chlorodiethylaluminum [Diethylaluminum chloride]
- 76-06-2 – Chloropicrin
- No CAS# – Chloropicrin and methyl bromide mixture
- No CAS# – Chloropicrin and methyl chloride mixture
- 80-15-9 – Cumene hydroperoxide
- 675-14-9 – Cyanuric fluoride
- 110-22-5 – Diacetyl peroxide
- 334-88-3 – Diazomethane
- 94-36-0 – Dibenzoyl peroxide
- 110-05-4 – Dibutyl peroxide (tertiary)
- 7572-29-4 – Dichloroacetylene
- 557-20-0 – Diethylzinc
- 105-64-6 – Diisopropyl peroxydicarbonate
- 105-74-8 – Dilaluroyl peroxide
- 97-02-9 – 2,4 Dinitroaniline
- 1338-23-4 – Ethyl methyl ketone peroxide [methyl ethyl ketone peroxide]
- 371-62-0 – Ethylene fluorohydrin
- 684-16-2 – Hexafluoroacetone
- 10035-10-6 – Hydrogen bromide
- 7722-84-1 – Hydrogen peroxide
- 7803-49-8 – Hydroxylamine
- 463-51-4 – Ketene
- 78-85-3 – Methacrylaldehyde
- 920-46-7 – Methacryloyl chloride
- 30674-80-7 – Methacryloyloxyethyl isocyanate
- 74-83-9 – Methyl bromide
- 1338-23-4 – Methyl ethyl ketone peroxide
- 453-18-9 – Methyl fluoroacetate
- 421-20-5 – Methyl fluorosulfate
- 74-88-4 – Methyl iodide
- 79-84-4 – Methyl vinyl ketone
- 100-01-6 – Nitroaniline [para-Nitroaniline]
- 10102-44-0 – Nitrogen dioxide
- 10102-44-0 – Nitrogen Oxides (NO; NO2; N204; N203)
- 10544-72-6 – Nitrogen tetroxide [Nitrogen peroxide]
- 7783-54-2 – Nitrogen trifluoride
- 10544-73-7 – Nitrogen trioxide
- 72-52-5 – Nitromethane
- 20816-12-0 – Osmium tetroxide
- 7783-41-7 – Oxygen difluoride [Fluorine monoxide]
- 10028-15-6 – Ozone
- 19624-22-7 – Pentaborane
- 7601-90-3 – Perchloric acid
- 7616-94-6 – Perchloryl fluoride
- 627-3-4 – Propyl nitrate
- 107-44-8 – Sarin
- 7783-79-1 – Selenium hexafluoride
- 7803-52-3 – Stibine (Antimony hydride)
- 5714-22-7 – Sulfur pentafluoride
- 7783-80-4 – Tellurium hexafluoride
- 10036-47-2 – Tetrafluorohydrazine
- 7719-09-7 – Thionyl chloride
- 1558-25-4 – Trichloro (chloromethyl) silane
- 27137-85-5 – Trichloro (dichlorophenyl) silane
- 2487-90-3 – Trimethyloxysilane
NOTE: SAFTENG members can see the full comparison I did back in February 2012 Here.
What does all this mean?
It means there are over 70 PSM HHC’s that have the potential of now being covered as a mixture and since these HHCs are NOT on EPA’s RMP listing, they would now be covered as of last Monday if they are in a mixture with the total weight of the chemical in the process at a concentration of one (1) percent or greater and the partial pressure of the chemical in the vapor space under handling or storage conditions is more than 10 millimeters of mercury (mm Hg).
What does this change to the 1% rule do to the “battery limits” of my covered process?
This aspect of OSHA’s change in mixtures applicability could have the greatest impact. There are facility’s that considered their waste streams and/or their “reacted product” as NOT being covered under the PSM standard. Yes, it is true that the waste stream(s) and/or reacted product stream(s) is “interconnected” to the covered process, but a lot businesses spent a lot of time, effort, and money (right or wrong) to demonstrate that the process would not release the HHC in its original form from the process beyond their prescribed battery limit(s). Some of these process streams may have some lesser concentration of the HHC; such as unreacted HHC/EHS. Now, as of last Monday, if this stream(s) contains 1% or more of the HHC the process battery limit now changes and previously thought “uncovered” part of the process now becomes “covered”. For example:
A process battery limit ends at the discharge valve of a processing vessel. The facility has demonstrated that the HHC/EHS in its original concentration will not make it beyond this valve and therefore the facility has drawn its battery limit(s) for the “covered process” to end at this valve. But in their battery limit documentation, it shows that the contents of the finished product stream beyond this vessel discharge valve contain a mixture with greater than 1% of the HHC AND the partial pressure of the HHC in the process stream exceeds 10 mm Hg. As of last Monday, this meant the “covered process” would now extend ALL the way through the packaging of the finished product and even warehousing of this finished product (e.g. finished product has greater than 1% of the HHC and partial pressure is over 10 mm Hg). Now think about the implications for the customer who buys this product… they now have to consider if their operation will be a PSM-covered process because this “product” is a mixture with the total weight of the HHC at a concentration of one (1) percent or greater and the partial pressure of the HHC in this mixture is greater than 10 mm Hg.
What does this change do to my Maximum Intended Inventory (MII)?
We may have to revise our MII and now include the streams that may have been excluded due to their low concentrations. With this 1% rule we may have storage of waste streams that meet this new applicability definition and thus, we now have to include it in our MII documentation, as well as include these streams in our PSM program as mentioned above.
So this change may have overnight created a new covered process(s), increased a PSM process’s MII, and very well may have established new battery limits for already PSM covered processes.
I am looking for either waste streams or finished product streams that have a mixture with the total weight of the HHC at a concentration of one (1) percent or greater and the partial pressure of the HHC in this mixture is greater than 10 mm Hg. Especially if your HHC is one of those listed above.