Free tools / EPCRA Tier II Checker

Does this chemical trigger Tier II reporting?

EPCRA Section 312 makes you file a Tier II Inventory Form with your State Emergency Response Commission, your Local Emergency Planning Committee, and your local fire department any year you stored an "Extremely Hazardous Substance" above its Threshold Planning Quantity (TPQ), or any hazardous chemical above 10,000 pounds at any one time. The TPQs vary by chemical — anhydrous ammonia is 500 lb, chlorine is 100 lb, hydrofluoric acid is 100 lb — and the list of ~360 EHSs takes a while to navigate. This tool tells you whether the chemical you're holding triggers the form.

Check a chemical EPA full EHS list ↗

Why this matters

The Tier II form has a March 1 deadline. Missing it is a per-day civil penalty.

Tier II Inventory Forms cover the preceding calendar year and are due to your SERC, LEPC, and local fire department by March 1 every year. The civil penalty for failing to report runs up to $63,361 per violation per day (the EPA's 2024 inflation-adjusted maximum). A multi-site employer with five sites that should have reported but didn't accumulates penalties fast.

Two thresholds drive the form. The "Extremely Hazardous Substance" (EHS) list at 40 CFR Part 355 Appendix A carries ~360 chemicals + a per-chemical Threshold Planning Quantity (TPQ) in pounds. If you stored any EHS above its TPQ at any one time during the year — even briefly — you owe a Tier II. The TPQs are aggressive: chlorine at 100 lb, anhydrous ammonia at 500 lb, hydrofluoric acid at 100 lb. A 55-gallon drum of pretty much anything on the list is over.

The second threshold catches everything else. If a chemical is not on the EHS list but is "hazardous" under OSHA Hazard Communication (requires a Safety Data Sheet), you owe Tier II if you stored more than 10,000 pounds of it at any one time. That's roughly a small warehouse of paint, a few totes of cleaning chemicals, or a small tank of fuel oil (which has its own 10,000-gallon special threshold at retail gas stations).

This tool isn't a regulatory replacement — the EPA's Appendix A is authoritative + the SERC's filing portal is the final word — but it shoulders the 90% case: the EHS you're holding is on the list, the TPQ is straightforward, and your only question is "do I owe the form this year?".

What the checker covers

50 EHS entries by name + CAS — covers ~90% of industrial use cases.

The chemical database in this tool covers the 50 most-commonly-stored EHSs across manufacturing, agriculture, warehousing, and chemical-plant operations. Each entry carries the chemical's TPQ, its CAS number, and short common-name aliases. Searching for "NH3" finds anhydrous ammonia; searching for the CAS finds it too; searching for "ammonia" matches with disambiguation between anhydrous + aqueous (which has a separate TPQ).

Chemicals not in the curated list fall through to a "consult EPA Appendix A" hint with the canonical link. Non-EHS hazardous chemicals (anything else requiring an SDS) are checked against the universal 10,000-pound threshold automatically — pick "Not on the EHS list" + enter your quantity.

Common gotchas

The Tier II rules that bite people.

"At any one time" means peak inventory. A 600-lb peak in May still triggers reporting even if the year-end balance is zero. Pull the high-water mark from inventory records, not the year-end snapshot.
Aqueous solutions have their own TPQ. Anhydrous ammonia (gas) at 500 lb is one chemical; aqueous ammonia (NH4OH solution) at 1,000 lb is a separate entry on the EHS list. Pick the right one.
Mixtures count toward the TPQ. A solution that's 5% chlorine dioxide counts at its chlorine-dioxide weight, not the total solution weight. The de-minimis exception applies below 1% (0.1% for carcinogens) per the OSHA HazCom rule that Tier II references.
Diesel + gasoline have a special rule. Retail gas stations get a 10,000-gallon threshold combined for motor fuels stored entirely below grade. Non-retail (fleet refueling, industrial use) still triggers at 10,000 pounds.
Tier II + Form R are different obligations. Tier II is annual inventory; Form R (Toxic Release Inventory under EPCRA Section 313) is annual emissions. Different chemical list, different thresholds, different form. Both due March 1 + July 1 respectively.

Check a chemical against the threshold.

Pick the chemical (by name, CAS number, or common alias), enter your peak inventory in pounds, and the checker tells you whether you owe a Tier II this year + which threshold tripped (EHS TPQ vs the universal 10,000-pound rule).

Check a chemical How SE auto-tracks Tier II →

SE's chemical-safety platform monitors your inventory daily against the EPCRA Section 312 thresholds (EHS TPQs + the 10,000-pound rule) + the Section 313 Form R thresholds + state-specific lists (California Proposition 65, Massachusetts TURA), and auto-generates the Tier II + Form R PDFs at year-end from the same inventory rows that hit the threshold. The free checker above is the one-chemical version; the platform makes it continuous + multi-site.