When is disclosure required?

If you use, handle or store hazardous materials in quantities equal to or greater than the following threshold quantities:

  • 55 gallons of a liquid
  • 500 pounds of a solid
  • 200 cubic feet of a gas


Extremely Hazardous Substances (EHS) – Federal and State laws now mandate special reporting of chemicals found on the EHS list maintained by the US EPA. You must report any of these chemicals if the amounts on hand at any given time exceed the “Threshold Planning Quantity” (TPQ) on the list, or if they exceed the general quantities listed above (55 gallons/500 pounds/200 cubic feet), whichever is less.

EXAMPLE: Chlorine gas is on the EHS list, with a TPQ of 100 pounds. You have up to 150 pounds stored on-site at any given time (a standard chlorine cylinder is 150 pounds). Even though you handle less than the 500-pound general quantity, you must still disclose because chlorine gas is a listed chemical.

The EHS list can be found on the web at the EPA.

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