Reportable Quantities. Threshold Planning Quantities. Trigger Quantities.
These chemical emergency preparedness and reporting terms sound like they could be interchangeable. The same goes for the terms “hazardous substances,” “extremely hazardous substances,” “hazardous chemicals” and “toxic chemicals.” But in fact, these terms mean very different things in the context of the Environmental Protection Agency (EPA) programs to which the terms apply.
Let’s break down these key terms and identify the emergency planning and right-to-know programs in which each term is used.
What are "Hazardous Substances"?
Authorized in 1980 and often called the "Superfund" program, the Comprehensive Environmental Response Compensation and Liability Act (CERCLA) commanded the EPA to create a list of hazardous substances. This list is found at 40 CFR 302.4. There are several hundred substances on the list, which includes both common chemicals (such as acetone, acetone cyanohydrin, and aldrin) and Resource Conservation and Recovery Act (RCRA) listed and characteristic hazardous wastes. The list is in alphabetical order by substance name from acenaphthene through zirconium tetrachloride, followed by the RCRA F- and K-listed wastes.
What are "Extremely Hazardous Substances"?
Signed into law in 1986, the Emergency Planning and Community Right-to-Know Act (EPCRA) directed the EPA to publish a list of extremely hazardous substances. This list is found in 40 CFR 355, Appendix A. It includes a number of chemicals that are also on the CERCLA hazardous substances list (for instance, acetone cyanohydrin). The list is in alphabetical order by substance name, from acetone cyanohydrin through zinc phosphide.
What are "Hazardous Chemicals"?
Two EPCRA programs refer to “hazardous chemicals.” In this context, EPA refers to the Occupational Safety and Health Administration (OSHA) definition of hazardous chemical found under 29 CFR 1910.1200. OSHA does not provide an actual list of hazardous chemicals, but rather criteria to determine whether a chemical is hazardous and therefore subject to OSHA’s hazard communication (HazCom) standard.
What are "Toxic Chemicals"?
EPCRA also required the EPA to create a separate list of toxic chemicals for the purposes of toxic release inventory reporting. This list of toxic chemicals is located at 40 CFR 372.65. There are over 600 chemicals on the list, some of which are also hazardous substances under CERCLA (like aldrin) or extremely hazardous substances under EPCRA (such as acrylonitrile). The list is in alphabetical order from abamectin to zineb and includes the date each chemical was added to the list.
What is a "Reportable Quantity" (RQ)?
The term “reportable quantity” is used in two different regulatory programs: the CERCLA release reporting requirements found at 40 CFR 302, and the EPCRA release reporting requirements found at 30 CFR 355. In both cases, the reportable quantity is the amount at or above which a release of the substance in question must be reported to various agencies.
Under the CERCLA regulations, reportable quantities are identified in Column 5 of the List of Hazardous Substances table located at 40 CFR 302.4. Each substance has its own reportable quantity, ranging from 1 lb. (for chemicals like aldrin and vinyl chloride) to 5,000 lbs. (for chemicals like acetone and sodium phosphate). Releases at or above these RQs to the environment must be reported to the National Response Center (NRC).
Under the EPCRA regulations, reportable quantities are identified in Column 4 of the Extremely Hazardous Substance List found at 40 CFR 355, Appendix A. For any chemical that is also on the CERCLA Hazardous Substances List (for instance, acetone cyanohydrin), the RQ will be the same on both tables. For any chemical that is only on the EPCRA list, the RQ can be established by the EPA at anywhere from 1 lb. to 5,000 lbs. Releases at or above these amounts into the environment that could also affect persons outside the facility boundaries must be reported to all potentially affected Local Emergency Planning Committees (LEPCs) and State Emergency Response Commissions (SERCs).
What is a "Threshold Planning Quantity" (TPQ)?
Under 40 CFR 355, facilities are required to coordinate emergency planning efforts with LEPCs if the facility has any EHS on site at or above the TPQ at any one time. Some EHS have two TPQs in Column 5 (for instance, acrylamide). In such cases, the lower of the two TPQs is used when the EHS is handled in certain (usually more dangerous) ways, such as in molten form.
What are "Trigger Quantities"?
Two different EPCRA programs refer to “trigger quantities.”
Under 40 CFR 370, any facility that has a hazardous chemical on site at any one time at or above the appropriate “trigger quantity” must provide copies of the substance’s Safety Data Sheet (SDS) to local and State authorities within 3 months and must submit the Tier II inventory report on or before March 1. In this context, the “trigger quantity” is 10,000 lbs. or more on site at any one time for any OSHA hazardous chemical. For "extremely hazardous substances," the trigger quantity will be 500 lbs. or the TPQ found in 40 CFR 355, whichever is lower.
Under 40 CFR 372, any facility that has manufactured, processed, or used any toxic chemical listed in 40 CFR 372.65 must submit the Toxic Release Inventory (TRI, or Form R) by July 1. In this context, the “trigger quantity” is based on the activity: for manufacturing or processing, the trigger is 25,000 lbs. in a calendar year; for any other use, the trigger is 10,000 lbs. in a calendar year. For this program, there are also significantly lower trigger quantities for “chemicals of special concern” (i.e., those that are persistent, bioaccumulative, and toxic).
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