Tier II Chemical List: 500-Pound and 10,000-Pound Thresholds

Tier II chemical reporting thresholds are set at two levels under the Emergency Planning and Community Right-to-Know Act: 500 pounds (or the substance’s lower Threshold Planning Quantity) for any Extremely Hazardous Substance, and 10,000 pounds for every other hazardous chemical that requires a Safety Data Sheet under OSHA’s Hazard Communication Standard.¹ If any chemical at your facility crossed one of those thresholds at any single moment during the previous calendar year, you owe a Tier II report by March 1.²

The peak quantity is what matters. Not the annual average, not what’s on hand today. If a tank was full for one afternoon in August and that fill pushed you over the threshold, the chemical is reportable for the whole year.

The 500-Pound Threshold for Extremely Hazardous Substances

Extremely Hazardous Substances (EHS) are a fixed list the EPA compiled because of their potential to cause serious, irreversible health effects from accidental releases.³ The list, each substance’s Threshold Planning Quantity, and its CAS registry number all appear in Appendix A to 40 CFR Part 355.⁴

The Tier II trigger for any EHS is 500 pounds or that substance’s TPQ, whichever is lower.¹ Some TPQs sit as low as 10 pounds, and in those cases the 500-pound number is irrelevant. Ten pounds on site at one time triggers the report.

When an EHS is part of a mixture or solution, you count only the weight of the EHS component itself, not the total mixture weight.⁵ Sulfuric acid has a TPQ of 1,000 pounds, so the reporting threshold is 500 pounds. A facility with a bank of non-consumer lead-acid batteries has to sum the sulfuric acid across every battery to see whether the 500-pound line is crossed.⁶

The 10,000-Pound Threshold for Everything Else

Any chemical that requires a Safety Data Sheet under OSHA’s Hazard Communication Standard and is not on the EHS list falls into the general category. The trigger is 10,000 pounds present at the facility at any one time during the calendar year.¹ That covers solvents, acids, compressed gases, cleaning agents, and much more.

There is no master list here the way there is for EHS. Whether a chemical qualifies depends on its hazard classification and whether OSHA’s rule requires an SDS.⁷ If you have an SDS on file and the peak amount at any one time was 10,000 pounds or more, it gets reported.

Non-retail facilities that store gasoline, diesel, or heating fuel use this same 10,000-pound threshold. That works out to roughly 1,639 gallons of gasoline or 1,351 gallons of diesel, so a moderate above-ground fuel tank at a warehouse or fleet yard can easily trip it.

Retail Gas Station Thresholds

Retail gas stations get much higher thresholds because fuel storage is the nature of the business. Gasoline is reportable at 75,000 gallons (all grades combined) and diesel at 100,000 gallons (all grades combined).¹ A retail gas station for this purpose is a facility that sells gasoline or diesel principally to the public for motor vehicle use on land.

Both of the following must be true throughout the preceding calendar year for the elevated numbers to apply:

The fuel was stored in tanks that were entirely underground.
Every underground storage tank at the facility was in compliance with all applicable UST requirements under 40 CFR Part 280 (or an EPA-approved state UST program) at all times.⁸

If a single tank was out of compliance, the whole facility loses the elevated threshold and drops back to the standard 10,000 pounds for the fuel itself.⁸ It is all or nothing.

Chemicals That Don’t Count Toward the Threshold

Several categories of chemicals are excluded from Tier II reporting entirely, which means they never count toward the 500-pound or 10,000-pound triggers:

Food, food additives, color additives, drugs, and cosmetics regulated by the FDA.
Substances present as a solid in a manufactured article, when no exposure occurs under normal use.
A chemical packaged in the same form and concentration as a product sold to the general public, even if your facility uses it for a different purpose.
Chemicals used in a research laboratory, hospital, or other medical facility under the direct supervision of a technically qualified individual.
Chemicals used in routine agricultural operations, and fertilizers held for sale by a retailer to the end customer.⁹

The consumer-format exemption is the one that trips facilities up. A 55-gallon drum of a cleaning product is reportable even if the same product sits on hardware-store shelves in quart bottles. The exemption turns on packaging and concentration matching the consumer version, not on the chemical identity.

Where to File Once You’ve Crossed a Threshold

A Tier II report has to reach three separate recipients: your State Emergency Response Commission (SERC), your Local Emergency Planning Committee (LEPC), and the fire department with jurisdiction over your facility.¹⁰ Missing any one of the three leaves the filing incomplete.

The EPA provides free software called Tier2 Submit, part of its CAMEO suite, for preparing the electronic form. Only the current year’s version can be used for the current reporting year.¹¹ For reporting year 2025, due March 1, 2026, the version is Tier2 Submit 2025.

Check with your SERC before you file. Many states use an online portal called E-Plan that accepts electronic Tier II filings directly. Some states mandate that portal; some accept Tier2 Submit files; some have their own forms. An improperly formatted submission can be treated the same as no submission at all. States also charge filing fees that range from nothing to roughly $25 for basic filings, with higher tiers in some states based on chemical count or volume stored.

What Happens If You Miss the Threshold Trigger

The statute sets a civil penalty of up to $25,000 per violation for failing to report under Section 312, and each day the violation continues counts as a separate violation.¹² After inflation adjustments, the current maximum is $71,545 per violation per day.¹³

The daily accrual is the real exposure. A facility that misses March 1 and files in June is theoretically exposed to a penalty calculation running across every intervening day. Enforcement often begins with a notice of noncompliance, which is a chance to fix the problem before penalties are assessed, but it is not a guarantee that penalties won’t follow.

States Can Set Lower Thresholds

Federal thresholds are a floor, not a ceiling. States can set lower reporting thresholds, add chemicals to their own EHS lists, and impose reporting obligations that go beyond 40 CFR Part 370. Your SERC or state environmental agency is the authoritative source for those state-specific rules, and confirming them before your first filing is essential. A facility that meets every federal threshold analysis can still be out of compliance under state law.

1
eCFR. 40 CFR 370.10 – Who Must Comply With the Hazardous Chemical Reporting Requirements of This Part
2
eCFR. Part 370 Hazardous Chemical Reporting: Community Right-to-Know
3
U.S. Environmental Protection Agency. What Are Extremely Hazardous Substances (EHSs)?
4
eCFR. Appendix A to Part 355 – The List of Extremely Hazardous Substances and Their Threshold Planning Quantities
5
Federal Register. Emergency Planning and Notification; Emergency Planning and List of Extremely Hazardous Substances and Threshold Planning Quantities
6
US EPA. How Does a Facility Report Batteries for Tier II
7
Occupational Safety and Health Administration. 29 CFR 1910.1200 – Hazard Communication
8
US EPA. Eligibility for Gasoline and Diesel Thresholds at Retail Gas Stations
9
eCFR. Part 370 Hazardous Chemical Reporting: Community Right-to-Know – Section 370.13
10
GovInfo. 42 USC 11022 – Emergency and Hazardous Chemical Inventory Forms
11
US EPA. Tier2 Submit Software
12
Office of the Law Revision Counsel. 42 USC 11045 – Enforcement
13
eCFR. 40 CFR 19.4 – Statutory Civil Monetary Penalties, as Adjusted for Inflation