A reportable quantity (RQ) is the amount of a hazardous substance that, if released into the environment within any 24-hour period, triggers a requirement to notify the government. Under federal law, the person in charge of a facility or vessel must report a release that equals or exceeds the RQ to the National Response Center (NRC) as soon as they know about it.
Reportable quantities matter because release reporting deadlines are measured in minutes and hours, not days. Facilities that do not know the RQs of the chemicals they handle can easily miss a required report, and failure to report can lead to significant penalties.
What Is a Reportable Quantity?
RQs come from the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), also called Superfund. EPA lists hundreds of hazardous substances and their RQs in 40 CFR Part 302, mainly in the table at 40 CFR 302.4. RQs are set at one of five levels: 1, 10, 100, 1,000 or 5,000 pounds. The lower the RQ, the more hazardous EPA considers the substance.
A "release" is defined broadly. It includes spills, leaks, emissions, discharges, dumping and leaching into the air, water or land. A release counts toward the RQ whether it happens all at once or over the course of the 24-hour period.
In 2024 EPA designated PFOA and PFOS, two PFAS chemicals, including their salts and structural isomers, as CERCLA hazardous substances with an RQ of 1 pound. The D.C. Circuit upheld the designation in August 2026, so facilities that handle these substances should include them in their release reporting procedures.
CERCLA and EPCRA Release Reporting
Two federal laws use RQs for release reporting:
- CERCLA Section 103: requires the person in charge to immediately notify the NRC of a release of a CERCLA hazardous substance at or above its RQ within a 24-hour period. The NRC can be reached 24 hours a day at 1-800-424-8802.
- EPCRA Section 304: requires facilities that produce, use or store hazardous chemicals to immediately notify the State Emergency Response Commission (SERC) and Local Emergency Planning Committee (LEPC) for any area likely to be affected when a release of an extremely hazardous substance or CERCLA hazardous substance at or above its RQ could cause exposure off site. A written follow-up report is required as soon as practicable afterward. These rules are in 40 CFR Part 355.
Many states have their own spill reporting laws with different thresholds, so a release below a federal RQ may still need to be reported to the state. EPCRA also governs annual chemical inventory reporting, covered on our EPCRA Tier II reporting page.
Exemptions and Special Cases
- Federally permitted releases: releases allowed under a permit, such as a Clean Water Act discharge permit, are generally exempt from CERCLA reporting.
- Petroleum exclusion: crude oil and petroleum products are excluded from the CERCLA definition of hazardous substance. Oil spills to water are reported under the Clean Water Act instead, and prevention is covered by the SPCC rule.
- Continuous releases: releases that are continuous and stable in quantity and rate may qualify for reduced reporting under 40 CFR 302.8.
- Mixtures: for mixtures and solutions, a release is reportable when the amount of a hazardous substance in the mixture reaches its RQ.
RQ on Shipping Papers
The U.S. Department of Transportation also uses RQs. A material is a DOT "hazardous substance" when it appears in Appendix A to 49 CFR 172.101 and is in a single package in a quantity equal to or greater than its RQ. When this happens, the letters "RQ" must appear on the shipping paper with the basic description, and packages must be marked with "RQ" in addition to other required markings. This lets responders know that a spill of the package could require release reporting. See our page on hazardous materials transportation for the broader shipping rules.
Common Examples
- A tank fitting fails and leaks a liquid hazardous substance onto the ground, and the amount released in a day exceeds its RQ.
- A process upset releases a gas such as ammonia or chlorine above its RQ to the air.
- A truck carrying drums of a listed substance crashes and spills more than the RQ.
- Small leaks from a valve over a full day add up to more than the RQ.
How to Respond to a Release Step by Step
- Protect people first. Follow your emergency action plan, evacuate or shelter as needed and call 911 if there is an immediate danger.
- Identify the substance. Use labels, shipping papers and safety data sheets to confirm what was released.
- Estimate the amount. Make a reasonable, conservative estimate of how much was released within the 24-hour period.
- Compare to the RQ. Look up the RQ in 40 CFR 302.4 or, for extremely hazardous substances, the EPCRA list. When in doubt, report.
- Notify immediately. Call the NRC and, if the release could affect people off site, the SERC and LEPC. Check state reporting requirements as well.
- Contain and clean up. Stop the release if it is safe to do so and begin cleanup with trained personnel.
- Submit written follow-ups. Provide EPCRA written follow-up reports and any state reports required.
- Investigate and document. Record the event, the reports made and the root cause, and assign corrective actions.
Common Mistakes to Avoid
- Delaying the call while trying to calculate an exact quantity.
- Assuming a release that stayed on site does not need a CERCLA report.
- Forgetting to notify the SERC and LEPC as well as the NRC.
- Not counting small releases that add up within 24 hours.
- Ignoring stricter state spill reporting thresholds.
- Not keeping a list of on-site substances and their RQs.
How SMS360 Helps
SMS360's Incident Management module helps teams record spills and releases, document who was notified and when, and assign follow-up actions. Safety Data Sheets keeps chemical information easy to find during a response, and Actions Management tracks corrective actions to prevent repeat releases.
Frequently Asked Questions
Who do I call to report a release above the RQ?
Call the National Response Center at 1-800-424-8802 for CERCLA releases. If the release could cause exposure off site, also notify the SERC and LEPC under EPCRA, and check your state's spill reporting rules.
Does the 24-hour period mean I have 24 hours to report?
No. The 24-hour period is used to add up the amount released. Once you know a release has reached the RQ, you must report it immediately.
Do oil spills have a reportable quantity?
Petroleum is excluded from CERCLA. Oil discharges to navigable waters or adjoining shorelines are reported under the Clean Water Act, generally when they cause a sheen or violate water quality standards.
Why is "RQ" on my shipping paper?
It means a package contains a hazardous substance in an amount at or above its reportable quantity, so a spill from that package may require federal release reporting.
