EPCRA Tier II Reporting for Construction: Do You Need to File?

If your jobsite holds 10,000 lb or more of a hazardous chemical, or an Extremely Hazardous Substance at or above 500 lb or its Threshold Planning Quantity (whichever is lower), at any one time during the year, EPCRA section 312 requires a hazardous chemical inventory report by March 1 (40 CFR 370.10, 370.45). It is an EPA rule (40 CFR Part 370), not an OSHA HazCom rule, so a clean SDS library and good labels do not satisfy it. The federal minimum is Tier I; Tier II is due within 30 days when the SERC, the LEPC or the fire department asks for it, and some states require Tier II every year under state law. The usual construction trigger is diesel added up across the site, and the penalty runs up to $71,545 per day.

Tier II thresholds in one table

Tier II is a threshold report: you report the chemicals that crossed a quantity at some point in the year.

The threshold is measured against the maximum amount on site at any one time during the year. Not a year-end snapshot, not an average. If a chemical crossed the line for one day, it is reportable for that year.

2026 status: The thresholds and the March 1 date are unchanged. A November 2025 EPA rule on the inventory forms (90 FR 51187) was withdrawn on January 9, 2026 (91 FR 918). EPA then published a final rule on June 22, 2026 (91 FR 37022, effective August 21, 2026) that aligns the Tier I and Tier II hazard categories with the 2012 and 2024 OSHA HazCom Standard. The compliance date for the new hazard categories is January 1, 2028: EPA expects them in the 2027 reports due March 1, 2028.

EPCRA is an EPA rule, not OSHA HazCom

This is where most contractors get caught. Tier II is enforced by EPA and the states, not OSHA. The inventory overlaps, because both start from the chemicals you keep an SDS for, but the duties are different:

• OSHA HazCom (29 CFR 1910.1200, applied to construction by 29 CFR 1926.59) protects your workers: SDS access, labels, the written program, training.
• EPCRA Tier II (40 CFR Part 370) tells first responders and the community what is stored at your facility, so they can plan for a fire or a release.

You can run a flawless HazCom program and still owe a Tier II report. Separate agencies, separate deadlines, separate penalties.

Does my construction site need to file?

Two conditions, both required (40 CFR 370.10(a)): OSHA's HazCom Standard requires you to prepare or have an SDS for the chemical, and the chemical is present at the facility at or above its threshold at any one time.

EPCRA's facility (40 CFR 370.3) is "all buildings, equipment, structures, and other stationary items that are located on a single site or on contiguous or adjacent sites and that are owned or operated by the same person." Part 370 has no exemption for a site because it is temporary. And EPA has answered the contractor question head on: when a construction company brings chemicals onto a client's site, "The employer of the construction workers operates a facility during the construction phase and should, therefore, report on these hazardous chemicals if applicable thresholds are met." (EPA Q&A, Reporting responsibility for hazardous chemicals brought on-site by contractors, updated April 14, 2026). The client does not add your chemicals to its own count. A six-month bridge job with a bulk fuel tank can owe a report that a permanent office never will.

Equipment counts too when it works only on the site: EPA says "hazardous chemicals in a forklift used only within the facility would need to be considered, while chemicals in delivery trucks parked occasionally at the facility for unloading would not." (EPA Q&A on vehicles at a facility, updated April 14, 2026).

The 10,000-pound rule

At 10,000 lb or more of a single non-EHS hazardous chemical at any point in the calendar year, that chemical is reportable. The count is per chemical, added up across every container and storage area on the same facility. Splitting one chemical across three laydown yards on the same site doesn't split the total.

The EHS rule (the lower threshold)

For the Extremely Hazardous Substances listed in 40 CFR Part 355, Appendix A, the threshold is 500 lb or the substance's TPQ, whichever is lower. Several TPQs sit well below 500 lb, and then the TPQ governs:

When the TPQ is above 500 lb, the 500 lb cap wins. When it is below 500 lb, the TPQ wins. Look up every EHS you store instead of assuming 500.

Common myth, corrected: Muriatic acid is an EHS. It is not. Appendix A lists hydrogen chloride as a gas only. Muriatic acid, the water solution, is an ordinary hazardous chemical and counts toward the 10,000 lb threshold.

Common construction chemicals that count

Volumes are rough conversions. The real density is in SDS Section 9.

The aggregation trap (worked example)

EPCRA counts the total of a chemical present at the facility at any one time, summed across every container. This is the most common reason a contractor under-reports.

Say a highway job in August holds, at peak:

• one 1,000-gal bulk diesel tank, about 7,100 lb
• three 200-gal generator day tanks, about 4,260 lb together
• two stationary generators with 100-gal tanks, about 1,420 lb together

No single tank reaches 10,000 lb. The site does:

7,100 + 4,260 + 1,420 = 12,780 lb of diesel on hand

That site is over the 10,000 lb threshold and reports diesel for that calendar year, even if it dropped back below 10,000 lb in September. The report uses the maximum amount on hand (12,780 lb, entered as a range code), not the average.

Track peak quantities as they happen with the Chemical Inventory Template, instead of rebuilding them from memory in February.

Converting volume to weight (the step everyone skips)

Tier II is reported in pounds. Construction chemicals come in gallons, liters, drums and bags. EPA's instruction is to "multiply by an appropriate density factor" (40 CFR 370.43):

weight (lb) = volume (gal) × density (lb/gal)

The density is in SDS Section 9, often as specific gravity: multiply the specific gravity by 8.34 lb/gal, the weight of a gallon of water.

If the SDS gives no density, get the value from the supplier in writing. Don't guess: the number decides whether you cross the line. The EPCRA Tier II Threshold Screener does the conversion and the comparison in one step.

Tier I vs Tier II

• Tier I reports hazardous chemicals in aggregate, by hazard category. It is the federal minimum under section 312 (40 CFR 370.41, 370.45(a)).
• Tier II reports chemical by chemical: name, CAS, amounts, days on site, storage and location (370.42). Federally, it is due within 30 days of a request from the SERC, the LEPC or the fire department (370.45(b)).

EPA's own rule adds that some states require Tier II every year under state law, and that some require electronic filing and certification (370.40(b), 370.42). Your SERC tells you which one it wants and through which portal (370.40(c)).

What goes in the Tier II report

For each chemical at or above its threshold (40 CFR 370.42(s)):

1. Identity. The chemical or common name and the CAS number as the SDS gives them; for a mixture, the product name and CAS
2. Physical state and EHS status. Solid, liquid or gas; whether it is an EHS, and which EHS a mixture contains
3. Hazard categories. The ones that apply, from Section 2 of the SDS
4. Maximum amount on any single day, as a range code (370.43)
5. Average daily amount, as a range code
6. Number of days on site during the year
7. Storage type and conditions, for example above-ground tank, steel drum, cylinder; ambient or pressurized
8. Where it is stored at the facility

Plus the facility block: address, latitude and longitude, NAICS code, owner or operator, emergency contacts with a 24-hour phone number, and the signed certification (370.42(a) to (q)).

Deadlines and how to file

Don't forget section 311. Within three months of first crossing a threshold, the facility also sends the SDS for each chemical, or a list grouped by hazard, to the LEPC, the SERC and the fire department. It is a one-time filing, updated when a new chemical crosses a threshold or when significant new information comes in (40 CFR 370.30 to 370.33).

Exemptions a contractor can actually use

Part 370 does not cover (40 CFR 370.13):

• FDA-regulated food, food additives, color additives, drugs and cosmetics
• A substance present as a solid in a manufactured item, as long as normal use causes no exposure (cured concrete in place, finished steel)
• A substance used for personal, family or household purposes, or present in the same form and concentration as a product packaged for the general public
• A substance used in a research laboratory, hospital or medical facility under a qualified person's supervision, or in routine agricultural operations

And by statute, EPCRA's reporting does not apply to transportation, including storage incident to transportation (42 U.S.C. 11047).

What is not exempt: bulk fuel storage, laydown yards, chemical staging areas, and any drummed or bagged product you keep an SDS for. When in doubt, it counts.

Penalties for getting it wrong

These are EPA civil penalties under EPCRA section 325, adjusted for inflation in 40 CFR 19.4. Each day a violation continues is a separate violation (42 U.S.C. 11045(c)(3)).

For scale: a serious OSHA violation tops out at $16,550 and a willful or repeat one at $165,514 (29 CFR 1903.15(d)). A contractor who misses a diesel Tier II and runs a loose HazCom program can hear from both agencies about the same chemical.

Common mistakes to avoid

• Treating Tier II as an OSHA task. It's EPA. A perfect SDS binder doesn't file your inventory.
• Checking one container at a time. Add up every source of a chemical across the facility, at its peak.
• Using the average in the threshold test. The trigger is the maximum on hand at any one time.
• Assuming the EHS threshold is 500 lb. It is the lower of 500 lb or the TPQ. Chlorine and HF report at 100 lb.
• Calling muriatic acid an EHS. Only hydrogen chloride gas is listed.
• Guessing the density. Take it from SDS Section 9 before converting gallons to pounds.
• Stopping at the federal floor. Your state may require Tier II every year, a specific portal, extra fields or a fee.
• Forgetting the per-day clock. Filing two weeks late is fourteen days of exposure.

What to do next

1. Screen every chemical against the right threshold with the EPCRA Tier II Threshold Screener.
2. Keep a live inventory that records peak quantities by location, starting from the Chemical Inventory Template. The chemical inventory guide explains how the same list serves HazCom, the 30-year record and Tier II.
3. Assemble the report data with the EPCRA Tier II Builder, then file in the format your SERC asks for.
4. Reconcile the SDS library with the inventory so nothing countable is missing: see find the holes in your SDS library.
5. Calendar March 1 next to your HazCom dates with the OSHA Deadline Calendar.

In HazComFast, each jobsite's quantities sit on the inventory next to the SDS, threshold alerts flag a product at 80% of its Tier II threshold and again when it crosses, and a gallon count with no confirmed density is shown as an estimate instead of a pass. The whole rule set, federal and state, is on the EPCRA Tier II hub.

Related reading: The Ultimate Chemical Inventory Template for OSHA & Tier II · OSHA Chemical Storage Requirements · How to Read a Safety Data Sheet.

Note: General guidance, not legal advice. EPCRA is administered with the states: your SERC may require Tier II annually, a specific portal, extra fields or a fee. Confirm with your SERC and LEPC before filing.

Sources & verification: 40 CFR 370.10, 370.13, 370.30 to 370.33, 370.40 to 370.45 and the definition of facility, 40 CFR Part 355 Appendix A (TPQs) and 40 CFR 19.4, read on the eCFR (title 40 current to 2026-09-23); 42 U.S.C. 11045(c) and 11047 on govinfo.gov; EPA's EPCRA answers on contractors, vehicles and extensions on epa.gov; 90 FR 51187, 91 FR 918 and 91 FR 37022 on federalregister.gov; all read on 2026-09-26. OSHA penalties per 29 CFR 1903.15(d) (amounts in effect since January 15, 2025). This article absorbs the former "EPCRA Tier II Chemical Reporting for Construction" guide, merged on 2026-09-26. Not legal advice.