CERCLA Reportable Quantities and EPCRA 304: When a Chemical Release Needs to Be Reported

An employee reports a broken hose, a leaking tank, or chemical material on the ground. The immediate safety response is underway. The supervisor now has a different question: Does the law call for the facility to notify the government?

The answer is not based on how alarming a spill looks, whether the substance is called “hazardous” on an SDS, or how much product was stored before the incident. For an ordinary spill, federal release notification turns on the identity of the regulated substance, how much entered the environment during the relevant period, and applicable exemptions. There is a distinct statutory release category: abandoning or discarding closed receptacles containing regulated substances can count even if the receptacles remain intact and nothing visibly leaks. EPCRA §304 additionally calls for its own facility-coverage analysis and consideration of potential exposure to people beyond the facility boundary.

Two federal programs usually matter first:

• CERCLA §103(a) calls for immediate notice to the National Response Center (NRC) for qualifying releases of CERCLA hazardous substances.
• EPCRA §304 calls for immediate notice to the relevant State or Tribal Emergency Response Commission (SERC/TERC) and Local or Tribal Emergency Planning Committee (LEPC/TEPC) for qualifying releases of extremely hazardous substances (EHSs) or CERCLA hazardous substances. When a CERCLA and EPCRA duty both apply, both notification routes need to be satisfied.

For agency notification, work through the substance, release pathway, quantity, exemptions, and recipient tests below. Entry into a storm drain calls for prompt assessment of environmental and water-discharge reporting; the drain alone does not establish a CERCLA or EPCRA §304 duty.

CERCLA and EPCRA 304 at a glance

NRC: 1-800-424-8802 (Washington, DC: 202-267-2675). For state and tribal contacts, consult EPA's EPCRA §304 directory. An NRC call is not a substitute for needed SERC/LEPC calls; neither is an internal incident report. [Sources: 40 CFR 302.6; 355.40–355.43; EPA emergency release guidance.]

Start with the substance: not the size of the puddle

A reportable quantity (RQ) is the legally assigned threshold quantity used to determine whether a covered release calls for notification. For ordinary spills, the calculation generally concerns the regulated amount entering the environment; where closed containers are abandoned or discarded, their regulated contents can count under the separate statutory release definition. An RQ is not a safe spill quantity, a cleanup allowance, a tank-inventory limit, or a worker exposure limit. A release below the federal RQ can still be dangerous and may be reportable under other laws.

Establish the chemical's exact identity using the container label, the product formulation, supplier information, inventory records, and the SDS. SDS Section 3 may help with constituents and concentration; Section 6 addresses accidental releases. An SDS's general regulatory section may be incomplete or dated, so confirm the current regulatory listing independently. See How to Read a Safety Data Sheet.

Check the substance in two places:

1. CERCLA hazardous substance: 40 CFR 302.4, Table 302.4, using the Final RQ column. This also calls for analysis of certain hazardous wastes not individually named in the table under 40 CFR 302.4(b) and 302.5.
2. EPCRA extremely hazardous substance (EHS): 40 CFR Part 355, Appendices A and B, using the Reportable Quantity, not the Threshold Planning Quantity (TPQ). TPQs support emergency planning under EPCRA §302; they serve a different purpose.

The CAS number is useful for lookup, but the regulation states that the listed chemical name controls if the name and CAS identifier conflict. Check chemical form, salt, solution, and waste identity rather than assuming related products all have the same RQ.

Some CERCLA-listed categories have no established numerical RQ. In Table 302.4, the symbol ** in the Final RQ column identifies certain broad classes of compounds for which EPA has not established an RQ. EPA states that a release of such a category does not itself trigger CERCLA §103 notification on the basis of that generic listing. For example, the generic “Antimony Compounds” category has this designation, but several specific antimony substances are separately listed with numerical RQs. Verify the actual compound and any separate listing before concluding that no federal notice is due; independently check EHS, state, and other program requirements. A generic ** listing supplies neither a 1-lb nor a 100-lb RQ. EPA guidance on CERCLA substances without established RQs.

Unlisted hazardous wastes: the RQ can apply to the entire waste

An industrial waste is not automatically exempt simply because its waste name does not appear in CERCLA Table 302.4. First determine whether it qualifies as an unlisted hazardous substance under 40 CFR 302.4(b), based on the applicable hazardous-waste characteristics. Then apply 40 CFR 302.5(b):

Waste status can arise after a release. EPA explains that a non-designated material exhibiting a RCRA hazardous-waste characteristic can fall within CERCLA's unlisted-hazardous-substance rule if it was a waste before release or becomes waste afterward. For example, material that is not cleaned up, or is recovered only for eventual disposal, may become waste under RCRA's definition; a product merely being hazardous or spilled is not enough without the needed waste classification and characteristic. Evaluate these facts promptly and do not screen out an incident solely because the material was originally sold as a commercial product. EPA: Releases of wastes not individually listed as CERCLA hazardous substances.

• General unlisted-waste rule: the RQ is 100 lb of the qualifying waste.
• Toxicity-characteristic exception: if the unlisted waste exhibits toxicity under 40 CFR 261.24, the RQ is the CERCLA Table 302.4 RQ of the contaminant that causes that characteristic. The selected RQ applies to the weight of the waste released, not only the weight of the toxic contaminant in it.
• Multiple characteristics or contaminants: where more than one contaminant causes the toxicity characteristic, use the lowest applicable contaminant RQ. Where the waste exhibits toxicity and another covered hazardous-waste characteristic, use the lowest applicable RQ, as 40 CFR 302.5(b) directs.

These are regulatory rules for qualifying unlisted hazardous wastes, not a universal 100-lb limit for all discarded chemicals or all mixtures. Listed hazardous wastes call for their own applicable Table 302.4 entry and analysis. Establish the actual waste classification and separately examine any regulated constituents; do not use a simple “percent contaminant × total waste” calculation to override 40 CFR 302.5(b).

Check EPCRA facility coverage separately. 40 CFR 355.30(a) covers a facility that produces, uses, or stores a hazardous chemical, and 40 CFR 355.30(b) additionally calls for the covered RQ release. “Hazardous chemical” has the defined meaning and exclusions in 40 CFR 355.61, which refers to OSHA's hazard communication definition; do not equate it with every substance appearing on an environmental list. EPCRA §304's facility definition includes vehicles, rolling stock, and aircraft, while CERCLA uses a separate broad facility definition. No Tier II filing or inventory threshold is a prerequisite for §304 reporting. EPA: Facilities covered under EPCRA 304.

Example substance-specific RQs

For ordinary spills, the chemical examples above use pounds of the regulated substance released to the environment, not automatically pounds of a diluted commercial product, except where specific mixture or hazardous-waste rules call for a different calculation. For abandoned/discarded closed receptacles, assess their regulated contents under the separate rule in Section 2. Radionuclides call for a separate unit check: 40 CFR 302.5(a) provides that radionuclide RQs in Appendix B to Table 302.4 are expressed in curies, rather than the pound-based chemical RQs in Table 302.4. A regulated release can trigger notice at exactly the applicable RQ; “more than the RQ” is an unsafe shorthand. See 40 CFR 302.6(a) and 355.33.

Was there a release into the environment?

CERCLA's definition of environment includes ambient air, surface waters, groundwater, drinking-water supplies, land surface, and subsurface strata. The facility fence is not the environmental boundary. A hazardous substance discharged onto outdoor soil on company property can be reportable under CERCLA even if the substance has not left that property.

By contrast, a spill captured wholly on an intact indoor containment surface, with no amount of the regulated substance escaping into ambient air, land, or water, may not constitute an RQ release into the environment. A large amount spilled inside a building is not necessarily the amount released to the environment. EPA specifically addresses an indoor-floor example where an RQ was spilled indoors but less than an RQ escaped outdoors. The EPA concluded that the hypothetical facts did not trigger EPCRA §304. That conclusion depends on what actually entered the environment, not on whether anyone smelled a chemical. EPA: Spills onto concrete floors inside a building.

Do not equate “we contained it” with “nothing entered the environment.” Check whether vapors escaped into outdoor air, material reached bare soil, a floor drain led to waters or soil, or a stormwater system carried material off the site. The legal analysis turns on the path and quantity of the substance. An improperly characterized drain, a spill onto cracked pavement, or unmeasured vapor losses can change the answer.

Special case: abandoned or discarded closed containers

CERCLA's definition of a release expressly includes abandoning or discarding barrels, containers, and other closed receptacles containing hazardous substances. EPA states that this can trigger CERCLA §103 notification when the hazardous substance inside the discarded or abandoned receptacles reaches its RQ, even if the containers have not broken and no contents are visibly leaking. Under EPCRA §304, EPA also directs facilities to consider the total regulated substance in abandoned or discarded receptacles, where its RQ is reached and off-site human exposure is possible, subject to the program's facility conditions and exclusions. EPA: Hazardous substances in encapsulated form; EPA: Chemicals in abandoned containers under EPCRA.

Abandonment or disposal is different from ordinary storage, transport, or handling of intact containers. Do not presume that a sealed drum awaiting authorized pickup is an environmental release; establish whether it was actually abandoned or discarded and whether a valid exemption applies. The usual calculation based only on material physically escaping a container needs to not be used to rule out this specific statutory release category.

For ordinary spills, keep three figures distinct: the gross amount spilled, the amount that entered the environment, and the amount recovered afterward. Recovery before any material enters the environment can prevent that captured mass from becoming an environmental release. Once a substance has entered outdoor soil, ambient air, or water, subsequent cleanup generally does not retroactively erase the release for RQ screening; it may reduce continuing migration and consequences. This follows the regulatory definitions of “release” and “environment”; it is not a separate EPA numeric deduction rule. Use the separate rule above for abandoned or discarded closed receptacles. Where containment, evaporation, or recovery occurred in stages, reconstruct the sequence and document uncertainty. 40 CFR 302.3; EPA indoor spill example.

CERCLA and EPCRA differ at the property boundary. CERCLA may call for an NRC report for an environmental release that never crosses company property. EPCRA §304 has a narrower exemption for a release resulting in exposure to people solely within facility boundaries. EPA says potential off-site exposure is enough; no actual exposure, illness, neighbor complaint, or off-property deposit has to be proved. EPA further advises that an above-RQ release into the environment may potentially expose people off-site and therefore should be reported under §304. Do not label an outdoor soil spill “NRC only” merely because soil remediation will be on site. Apply 40 CFR 355.30 facility coverage and 40 CFR 355.31 exclusions; where off-site potential cannot be reliably ruled out, notify the SERC/LEPC as well. 40 CFR 355.31(a); EPA off-site exposure FAQ.

Count the correct quantity in the correct 24-hour period

Under CERCLA §103 and EPCRA §304, the RQ test uses any 24-hour period, not a calendar day starting at midnight. When multiple releases of the same substance at a facility occur within that period, assess the combined quantity. A series of smaller leaks may reach an RQ even when no individual leak does. Facility boundaries and source ownership sometimes call for closer analysis, especially at large multi-operator complexes.

If the first event already reaches the RQ, notify immediately; there is no right to wait until all later releases are measured. If smaller events cumulatively reach the RQ, notify immediately on learning that the threshold has been reached. EPA also explains that a later event in the same 24-hour window does not necessarily call for another separate notification for the same already-reported series; new facts, another substance, state rules, or responder requests can still justify updated contact. EPA: Multiple Releases During 24-Hour Period; Separate Releases of the Same Hazardous Substance.

The 24 hours are a measurement window, not a grace period for making the report. Both programs use immediate notification language.

What if the released product is a mixture?

For a solution with known hazardous constituent weights, use the released weight of each hazardous constituent and compare it with that constituent's RQ. For example, 300 lb of a solution that is verified to contain 5% benzene by weight represents 15 lb of benzene if the entire solution enters the environment. Benzene's CERCLA RQ is 10 lb, so the CERCLA quantity test is met. EPCRA applicability still calls for its own analysis.

Different chemicals' RQ fractions are not additive. If a release contains a known 5 lb of benzene (half its 10-lb RQ) and 50 lb of ammonia (half its 100-lb RQ), neither substance reaches its own RQ merely because both are present. EPA specifically says not to add fractions of RQs of different hazardous substances to create a reportable release; radionuclides have special mixture rules. This does not eliminate the distinct rule below for mixtures whose hazardous constituent quantities are unknown, or duties under another law. EPA: Are the quantities of different hazardous constituents additive?.

Where the quantity of one or more hazardous constituents is unknown, 40 CFR 302.6(b)(1) can call for reporting when the entire mixture equals or exceeds the lowest RQ among the hazardous constituents. EPA applies a similar mixture approach to EPCRA §304. EPA also advises using the upper end of an SDS concentration range when evaluating EHS mixture quantities for EPCRA reporting. Certain listed hazardous wastes and radionuclides have special rules. Do not automatically apply ordinary diluted-product arithmetic to a hazardous waste stream. EPA mixture FAQ; EPA concentration-range guidance.

Estimate conservatively and promptly from reliable facts: initial container mass, inventory change, concentration by weight, density when converting volumes, amount intercepted before environmental entry, estimated amount that entered each medium, emission or flow estimates, and amount recovered after release. Record assumptions and uncertainty. Do not subtract post-release recovery from the historical mass that already entered the environment. Report promptly when available information establishes a reportable release, and identify which estimates remain uncertain.

Decision tree: which government notifications apply?

Follow these yes/no branches. The NRC and SERC/LEPC determinations are independent; reaching the CERCLA branch does not end the EPCRA analysis.

1. Identify the substance or waste. Is it a CERCLA hazardous substance, a qualifying unlisted hazardous waste (including material that becomes such a waste following release), or an EPCRA EHS?
   • No: neither federal §103(a) nor §304 is triggered solely by that identity; check other release-reporting laws and verify uncertain identities before closing the decision.
   • Yes: identify the correct numerical RQ under Table 302.4, 40 CFR 302.5(b), or Part 355 Appendix A/B, then proceed to question 2. If the only CERCLA listing is a generic ** category without an established RQ, check whether the specific substance is independently listed or is an EHS; do not assume a numerical CERCLA RQ exists.
2. Did a covered release occur? Examine entry into ambient air, outdoor land, surface water, groundwater, and drainage pathways. Separately ask whether regulated material in closed receptacles was abandoned or discarded into the environment.
   • No environmental entry and no abandonment/discarding of closed receptacles: an entirely contained operational spill does not by itself meet these release tests; document containment and screen other obligations.
   • Yes, by physical entry or qualifying abandonment/discarding: proceed to question 3. For ordinary spills, count the amount entering the environment; for discarded/abandoned closed receptacles, assess the regulated contents under the special rule above.
3. Was the applicable RQ reached in any 24-hour period? Apply known/unknown mixture rules, waste-specific rules, and other same-substance releases in the applicable period. Do not add half an RQ of one substance to half an RQ of a different substance.
   • No: these federal RQ notification thresholds are not met on the established facts; document uncertainty, monitor continuing releases, and assess other laws.
   • Yes: proceed to both the CERCLA and EPCRA branches. Do not wait for the rest of the 24-hour window before making a needed call.
4. CERCLA branch: is it a CERCLA hazardous substance or qualifying hazardous waste?
   • Yes, with no specific CERCLA exemption: the person in charge needs to immediately call the NRC (1-800-424-8802). Then complete the EPCRA branch; one call does not necessarily satisfy both programs.
   • No, or a documented CERCLA exemption applies: no §103(a) NRC duty arises from that listing alone; still complete the independent EPCRA and other-law checks. Being an EHS alone does not make a substance CERCLA-listed.
5. EPCRA branch: does the facility produce, use, or store a “hazardous chemical” within 40 CFR 355.30(a) and 40 CFR 355.61?
   • No: §304's facility prerequisite is not met, although a CERCLA NRC duty may remain. Document why the definition does not apply.
   • Yes: proceed to question 6. The §304 facility inquiry includes vehicles, rolling stock, and aircraft; a Tier II filing is not needed.
6. Does a specific EPCRA 40 CFR 355.31 exclusion apply? In particular, can exposure to people solely within the facility boundaries actually be established? EPA says potential off-site exposure, without proof of injury or actual exposure, is enough for §304 notification.
   • Yes, based on documented facts: record the precise exclusion and independently satisfy any CERCLA and state duties.
   • No, or off-site exposure is reasonably possible: immediately notify the SERC/TERC and LEPC/TEPC for areas likely affected. For qualifying transportation events, the specific EPCRA 911 route described below may be used.

Every endpoint: protect people, check state/tribal/local, water, permit and DOT reporting rules, keep the call log, and issue written EPCRA follow-up as soon as practicable when needed. This is a reporting route, not a reason to delay a known immediate notice while every branch is documented. Continuous-release procedures call for separate qualification.

Quick routing table

NRC, SERC, and LEPC are different destinations

National Response Center. CERCLA assigns the NRC as the federal receiving point. When CERCLA applies, the person in charge of the vessel or facility needs to notify immediately upon knowledge of the reportable release. Phone: 1-800-424-8802; within Washington, DC: 202-267-2675. The NRC does not replace the state or local notices needed under EPCRA §304.

State or Tribal Emergency Response Commission and Local or Tribal Emergency Planning Committee. EPCRA §304 calls for the owner/operator to provide initial notice to the community emergency coordinator for the LEPC/TEPC for each area likely affected and the SERC/TERC for each state or tribe likely affected. Where no LEPC exists, the regulation directs notification to relevant local emergency response personnel. Many jurisdictions provide a designated state warning point or hotline. Confirm the officially accepted reporting route before an incident; use EPA's state contact page and current state/local instructions. 40 CFR 355.42(a).

Transportation exception. Under 40 CFR 355.42(b), the EPCRA §304 immediate notification requirement for a release during transportation or from storage incident to transportation may be satisfied by giving the needed information to the 911 operator (or local operator if 911 is unavailable). This is an EPCRA-specific provision; it does not cancel an otherwise applicable CERCLA NRC duty or other transportation requirements. The EPCRA written-follow-up requirement does not apply to those covered transportation events under 40 CFR 355.40(b)–(c).

Separate DOT incident reports. For incidents covered by 49 CFR 171.15(b) during transportation in commerce (including applicable loading, unloading, and temporary storage), the person in physical possession needs to notify the NRC as soon as practical, but by 12 hours after the occurrence, under §171.15(a). This is a DOT-specific deadline for the listed transportation incidents, not an extension of CERCLA's or EPCRA's immediate-notice requirements. Separately, 49 CFR 171.16 may call for a DOT Form F 5800.1 incident report no more than 30 days after discovery, subject to its triggering events and exceptions. Check each program's scope independently; a transportation incident may create more than one reporting duty.

What to say during an immediate EPCRA notification

Under 40 CFR 355.40(a), report as much as is known at the time; information-gathering needs to not delay the emergency notice. Prepare to provide:

1. Name or identity of each substance involved.
2. Whether it is an EPCRA EHS.
3. Estimated quantity involved in the legally covered release, identifying uncertainty: for an ordinary spill, the amount entering the environment; for abandoned/discarded closed receptacles, the relevant regulated contents counted under the special statutory release definition.
4. Time and duration, or best-known start time and whether the release continues.
5. Environmental medium or media: air, land, water.
6. Known or anticipated acute or chronic health risks, plus medical advice if appropriate.
7. Protective precautions, including evacuation or sheltering recommendations when appropriate and available.
8. Contact name and phone number for follow-up information.

Chemical identity is not optional because it is commercially sensitive. The EPCRA trade-secret claim procedures for other reporting sections do not authorize withholding chemical identity under EPCRA §304. Provide the known identity to the emergency authorities as needed by 40 CFR 355.40(a); do not assume a confidential SDS ingredient designation cancels the immediate-notice obligation. EPA EPCRA fact sheet, Trade Secrets section.

For an NRC call, furnish the same practical event details and answer the NRC operator's questions. Do not treat a written log or electronic internal ticket as proof a needed phone notification was made.

Written follow-up: EPCRA is not CERCLA

EPCRA §304 generally calls for a written follow-up emergency notification to the applicable SERC/TERC and LEPC/TEPC as soon as practicable after the incident, except for the transportation-related exception described above. Update the initial facts and include actions taken to respond and contain the release, known or anticipated health risks, and any relevant advice about medical attention. Send further updates if material facts change. EPA does not prescribe one universal federal form, although authorities may supply or request a format. 40 CFR 355.40(b), 355.41–355.43.

EPA's interpretive guidance considers 30 days generally sufficient for this written notice, but the CFR uses “as soon as practicable,” and a state or tribe may set a shorter requirement. Build a deadline directly from the applicable jurisdiction's instructions; do not treat day 30 as a safe automatic extension. EPA explanation.

By contrast, an ordinary CERCLA §103(a) call to the NRC does not create a routine CERCLA written-follow-up report to the NRC. Other provisions, permits, state rules, cleanup orders, and CERCLA's separate statutory notice provision may impose additional duties in particular circumstances; do not infer that the initial NRC call resolves every later obligation. EPA written-follow-up FAQ.

Exemptions and situations that need special review

Federally permitted releases. CERCLA §101(10) defines specific categories. Being a permitted facility does not automatically make an unplanned spill a federally permitted release. Verify that the particular release meets the legal definition and permit conditions; EPA guidance addresses the CERCLA and EPCRA relationship.

Petroleum. CERCLA §101(14) generally excludes petroleum, including crude oil and its fractions, from the definition of a hazardous substance, subject to important qualifications. This does not excuse Clean Water Act oil-discharge reporting, state spill reporting, or an EPCRA §304 duty involving an EHS constituent that independently meets its criteria. Do not simply apply benzene's 10-lb RQ to all gasoline as if gasoline were pure benzene; do not assume every petroleum-contaminated waste remains excluded. EPA petroleum explanation; EPA petroleum and EPCRA FAQ.

Pesticides, normal fertilizer use, and statutory exclusions. Federal law contains narrowly described exemptions, including certain qualifying pesticide applications and the normal application of fertilizer. They are not blanket exclusions for pesticide spills in storage or transportation. Review the actual statute and 40 CFR 355.31.

Continuous and stable releases. CERCLA §103(f)(2), 40 CFR 302.8, and 40 CFR 355.32 allow reduced, not zero, reporting only for releases that meet the regulatory definitions of continuous and stable in quantity and rate. Continuous means uninterrupted or routine, anticipated, intermittent and incidental to normal operations/treatment processes; stable means predictable and regular in amount and rate. An accidental spill is not exempt merely because a valve has leaked more than once. The person in charge needs a defensible foundation of release data, process records, engineering estimates, or professional judgment before using the reduced CERCLA procedure.

Prepare the complete continuous-release submission. 40 CFR 302.8(e)(1) specifies additional written-report items, including facility coordinates and case information, population-density ranges within one mile, nearby sensitive populations and ecosystems, the estimated total released during the previous year, pertinent receiving-water or well information where applicable, and a signed accuracy-and-stability statement. Prepare the full submission against the operative regulation and current EPA instructions.

The CERCLA continuous-release written-report recipient is EPA Headquarters, not the former EPA regional-office destination. Obtain current submission instructions directly from EPA's continuous-release reporting page. These 30-day deadlines belong to the special continuous-release process; they do not change the “as soon as practicable” rule for ordinary episodic EPCRA §304 written follow-up.

Other specific exemptions. The regulations include limited rules for certain radionuclide releases, certain combustion-related nitrogen oxide emissions, animal-waste air emissions at farms, and large-particle releases of specified metals under CERCLA. Application depends on their exact regulatory conditions; do not generalize. 40 CFR 302.6(c)–(e); 355.31.

Six illustrative reporting decisions

These are hypothetical calculations, not real incidents or final legal determinations for a facility. Assume no federally permitted release or other applicable exemption unless a scenario identifies one. State law may add notifications.

The CERCLA RQs above come from CERCLA Table 302.4. The chlorine, ammonia, sulfuric acid, and trimethylchlorosilane EHS RQs appear in Part 355, Appendix A. The Federal Register's June 13, 2019 final rule expressly uses trimethylchlorosilane as an EHS that is not a CERCLA hazardous substance. The ammonia aggregation principle is explained by EPA; EPA's off-site exposure guidance is critical to the benzene scenarios. EPA separately explains CERCLA reporting for abandoned closed receptacles and EPCRA §304 reporting for discarded containers. Each EPCRA scenario assumes the facility meets 40 CFR 355.30(a); a reader needs to verify that prerequisite.

Federal rules are only one layer: California and Texas examples

California. Cal OES states that certain significant releases or threatened releases of hazardous materials call for immediate notification to the State Warning Center, 1-800-852-7550, and the relevant Unified Program Agency (UPA) or 911, subject to the applicable reporting criteria. Under California's notification arrangements, these calls can also satisfy the immediate state/local EPCRA notification route, but do not replace a separate CERCLA NRC call when needed. State requirements may reach situations below a federal CERCLA RQ.

Texas. TCEQ's spill RQ guidance distinguishes a hazardous-substance discharge onto land (generally the CERCLA Final RQ under its spill rule) from a discharge into water (the smaller of that RQ or 100 lb, under the identified rule), and provides different petroleum thresholds. TCEQ describes state reporting as as soon as possible, not later than 24 hours, for spills subject to 30 TAC Chapter 327. That state timeframe never changes CERCLA's separate immediate NRC requirement or EPCRA's immediate notification requirement.

Facilities in other states, tribal jurisdictions, or local districts need to use the rules actually applicable there. Check special wastewater, stormwater, waterway, tank, air-permit, pipeline, and transportation programs. Even a substance not triggering CERCLA may trigger one of those programs.

How this relates to OSHA emergency response

OSHA's HAZWOPER emergency-response requirements in 29 CFR 1910.120(q) for general industry and 29 CFR 1926.65(q) for covered construction operations concern how employees are protected when responding to hazardous substance emergencies. They are not written around CERCLA RQ numbers. A release below an EPA RQ can present a serious emergency for workers; a release above an RQ can be managed through an appropriate safety plan without making it an OSHA emergency merely by its mass.

For employers whose employees respond, the applicable §1910.120(q) or §1926.65(q) sets requirements for advance planning, response roles, incident command, training, and protective measures. Employers that evacuate their employees and do not permit them to assist in handling the emergency may rely on the relevant paragraph (q)(1) evacuation-only exception if they provide the needed emergency action plan: 29 CFR 1910.38 for general industry or 29 CFR 1926.35 for construction. Confirm which standard and HAZWOPER scope apply to the actual work. See HazComFast's HAZWOPER Training Levels.

Assign someone outside the hazard area to manage notifications and preserve records while trained responders address life safety. Do not delay evacuation, medical treatment, or emergency dispatch to calculate a perfect RQ; do not delay a known needed agency notice to finish a cleanup report.

Record the decision: even when no federal notification was needed

A useful incident file permits another person to reconstruct the reporting decision without guessing. Keep:

• Facility/site, equipment, exact location, time found, likely start/end times, and weather or ventilation details relevant to the pathway.
• Product identifier, manufacturer, SDS version, CAS/regulated constituent names, and the dated legal source used for each RQ.
• For ordinary spills: initial amount present, gross amount spilled, amount intercepted before environmental entry, amount entering each environmental medium, amount recovered after environmental entry, calculation method, concentration/density assumptions, and uncertainty range. Never use post-release recovery to erase the prior entry amount.
• For abandoned or discarded receptacles: date and circumstances of abandonment/discarding; exact location; container count, type, condition, and status; identity and estimated total mass of each regulated substance inside all relevant receptacles; how those quantities were established; and evidence distinguishing actual abandonment/discarding from ordinary storage, handling, or transport. Record CERCLA exemptions, EPCRA facility coverage, potential off-site exposure, and uncertainties independently even if the containers never leaked.
• A time-stamped record of earlier releases of the same substance within the relevant 24-hour window and the facility-boundary rationale.
• Whether off-site exposure was reasonably possible, including site maps, drains, air pathways, monitoring observations, and responder assessment.
• Exact exemption relied upon, with a written factual basis; do not record merely “exempt.”
• NRC, SERC/TERC, LEPC/TEPC, 911, and state/local contacts considered; which were notified; call date/time and time zone; operator, reference or incident number; and a copy of the information provided.
• Written EPCRA follow-up, delivery evidence, corrections and updates, internal incident investigation, disposal documentation, and needed regulator/insurer communications.

Maintain current chemical identifiers and SDS links in the chemical inventory, and screen the inventory thresholds with the Tier II threshold screener. Inventory reports under EPCRA §312 (often called Tier II reports) document chemicals on hand, not whether a particular accidental release crossed an EPCRA §304 RQ. Do not substitute one program's records for another's.

The 2018 America's Water Infrastructure Act amended EPCRA's information-sharing arrangements involving state/tribal emergency response commissions and drinking-water authorities. This is principally an agency communication requirement; it does not replace a facility's §304 notices. EPA EPCRA overview.

Regulatory sources

1. CERCLA §103, 42 U.S.C. §9603, and 40 CFR 302.6, notification, aggregation, mixtures, and exemptions: https://www.ecfr.gov/current/title-40/chapter-I/subchapter-J/part-302/section-302.6
2. 40 CFR 302.3–302.5, definitions, hazardous-substance list and Final RQs, listed/unlisted hazardous waste: https://www.ecfr.gov/current/title-40/chapter-I/subchapter-J/part-302/section-302.4 ; https://www.ecfr.gov/current/title-40/chapter-I/subchapter-J/part-302/section-302.5 ; https://www.ecfr.gov/current/title-40/chapter-I/subchapter-J/part-302/section-302.3
3. EPCRA §304, 42 U.S.C. §11004; 40 CFR 355.30–355.43, exemptions, RQs, notice contents, recipients and timing: https://www.ecfr.gov/current/title-40/chapter-I/subchapter-J/part-355/subpart-C
4. 40 CFR Part 355, Appendix A, EHS names, RQs and separate TPQs: https://www.ecfr.gov/current/title-40/chapter-I/subchapter-J/part-355/appendix-Appendix%20A%20to%20Part%20355
5. EPA final rule, 84 FR 27536 (June 13, 2019), confirming trimethylchlorosilane is an EHS, not CERCLA hazardous substance: https://www.govinfo.gov/content/pkg/FR-2019-06-13/pdf/2019-12411.pdf
6. 40 CFR 302.8, continuous-release reporting: https://www.ecfr.gov/current/title-40/chapter-I/subchapter-J/part-302/section-302.8
7. 40 CFR 355.60–355.61, relationship to CERCLA; EPCRA facility and hazardous-chemical definitions: https://www.ecfr.gov/current/title-40/chapter-I/subchapter-J/part-355/subpart-D
8. EPA, “EPCRA Emergency Release Notifications”: https://www.epa.gov/epcra/epcra-emergency-release-notifications
9. EPA, “Facilities Covered Under EPCRA 304”: https://www.epa.gov/epcra/facilities-covered-under-epcra-304
10. EPA, “How Is an Off-Site Release Subject to EPCRA 304?”: https://www.epa.gov/epcra/how-site-release-subject-epcra-304
11. EPA, “CERCLA and EPCRA Continuous Release Reporting,” including the federal recipient matrix: https://www.epa.gov/epcra/cercla-and-epcra-continuous-release-reporting
12. EPA, “Hazardous Substance Designations and Release Notifications”: https://www.epa.gov/epcra/hazardous-substance-designations-and-release-notifications
13. EPA, state/tribal and local emergency contacts: https://www.epa.gov/epcra/state-contact-information-epcra-section-304-emergency-release-notification
14. EPA, multiple releases in a 24-hour period; separate releases of same substance: https://www.epa.gov/epcra/multiple-releases-during-24-hour-period ; https://www.epa.gov/epcra/separate-releases-same-hazardous-substance
15. EPA, indoor floor release: https://www.epa.gov/epcra/spills-concrete-floors-inside-building
16. EPA, EPCRA §304 mixtures; concentration ranges: https://www.epa.gov/epcra/epcra-304-release-notification-mixtures ; https://www.epa.gov/epcra/reporting-ehs-mixture-based-concentration-range
17. EPA, written follow-up; meaning of “as soon as practicable”: https://www.epa.gov/epcra/are-written-follow-notifications-needed-after-initial-telephone-notifications ; https://www.epa.gov/epcra/meaning-phrase-soon-practicable-emergency-release-notification
18. EPA, petroleum exclusion; relationship to EPCRA: https://www.epa.gov/epcra/cercla-petroleum-exclusion ; https://www.epa.gov/epcra/does-cercla-petroleum-exclusion-apply-epcra-release-notifications
19. EPA, EPCRA overview and America's Water Infrastructure Act amendment: https://www.epa.gov/epcra/what-epcra
20. OSHA, 29 CFR 1910.120(q) (general industry) and 29 CFR 1926.65(q) (construction), HAZWOPER emergency response, and their respective EAP provisions: https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.120 ; https://www.osha.gov/laws-regs/regulations/standardnumber/1926/1926.65 ; https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.38 ; https://www.osha.gov/laws-regs/regulations/standardnumber/1926/1926.35
21. California Governor's Office of Emergency Services, spill/release reporting: https://www.caloes.ca.gov/office-of-the-director/operations/response-operations/fire-rescue/hazardous-materials/spill-release-reporting/
22. Texas Commission on Environmental Quality, RQs and spill law: https://www.tceq.texas.gov/response/spills/spill_rq.html ; https://www.tceq.texas.gov/response/spills/spill_rules.html
23. PHMSA/DOT, 49 CFR 171.15, immediate notice of specified transportation incidents: https://www.ecfr.gov/current/title-49/subtitle-B/chapter-I/subchapter-C/part-171/subpart-B/section-171.15
24. PHMSA/DOT, 49 CFR 171.16, DOT hazardous-material incident report and exceptions: https://www.ecfr.gov/current/title-49/subtitle-B/chapter-I/subchapter-C/part-171/subpart-B/section-171.16
25. EPA, CERCLA categories without established RQs (Table 302.4 ** designation, specific-compound exceptions): https://www.epa.gov/epcra/how-do-cercla-requirements-apply-hazardous-substances-which-no-reportable-quantity-has-been
26. EPA, non-addition of known hazardous constituents' RQ fractions (nonradionuclides): https://www.epa.gov/epcra/are-quantities-different-hazardous-constituents-additive
27. EPA, EPCRA Fact Sheet, including §304 emergency notice content and §322 trade-secret limits: https://www.epa.gov/system/files/documents/2023-12/epcra-guide_final.pdf
28. EPA, “Release of a hazardous substance in an encapsulated form,” closed/abandoned receptacles under CERCLA §101(22): https://www.epa.gov/epcra/release-hazardous-substance-encapsulated-form
29. EPA, “Reportable quantity calculations for chemicals in abandoned containers,” EPCRA §304: https://www.epa.gov/epcra/reportable-quantity-calculations-chemicals-abandoned-containers
30. EPA, “Releases of wastes not individually listed as CERCLA hazardous substances,” including when a material becomes waste after release: https://www.epa.gov/epcra/releases-wastes-not-individually-listed-cercla-hazardous-substances