Questions cont'd - doe-hdbk-1101-20040026

DOE-HDBK-1101-2004

11.

There is an exemption for atmospheric storage and transfer of flammable liquids.

Are all atmospheric vessels excluded from coverage?

This exemption deals with storage and transfer of flammable liquids only. Atmospheric

storage and transfer of HHCs listed in Appendix A are not exempt. Further, atmospheric

storage tanks of flammable liquids may be covered if they are interconnected or in close

proximity to a covered process. Contractors should evaluate each situation based on local

site-specific considerations and document the technical basis for invoking this

exemption.

12.

Are activities such as atmospheric mixing, and blending of flammable liquids

covered under the Rule?

The requirements of the PSM Rule apply to such operations. The exemption for

atmospheric storage and transfer of flammable liquids does not apply to mixing and

blending operations, because such operations may generate static charges capable of

ignition.

13.

Are flammable liquids covered by the Rule when stored at atmospheric pressure in

tanks designed for pressure-service?

The Rule exempts storage of flammable liquids in atmospheric storage tanks in certain

instances. If a DOE contractor can reasonably show that the tank cannot be operated

above atmospheric pressure, then the exemption can still apply. The means to ensure

adherence to this operating practice should be reliable and documented.

14.

Are flammable liquid storage tanks that are gas-blanketed for vapor control,

covered by the PSM Rule?

Under the PSM Rule, an atmospheric storage tank means a tank which is designed to

operate at pressures from atmosphere through 0.5 p.s.i.g. Therefore, flammable liquid

storage in tanks in which gas blanketing is maintained at or below 0.5 p.s.i.g. is exempt if

it is not connected to a covered process. Tanks containing 10,000 pounds or more of a

flammable liquid are covered by the PSM Rule if they are gas blanketed at a pressure

greater than 0.5 p.s.i.g.

15.

Are warehouses that store HHCs considered covered processes if the total inventory

exceeds the TQ for Appendix A materials? For flammable materials? For

explosives?

Warehouses are covered by the PSM Rule if the total quantity of an HHC stored in one

location exceeds the TQ for the particular HHC. If a warehouse is used to store

containers of Appendix A HHCs and, either individually or collectively, they exceed

their TQs, then the warehouse is covered under the PSM Rule. However, atmospheric

storage of flammable liquids is covered under other OSHA regulations (e.g., 29 CFR

1910.106) and is not covered under this Rule. Further, explosives manufacturing is

covered under the PSM Rule. However, storage and use of explosives outside the

manufacturing process are covered under 29 CFR 1910.109, Explosives and Blasting

Agents; not under the PSM Rule.