Short answer: When a hazardous chemical first reaches its EPCRA reporting threshold at a facility, the owner or operator must, within three months, send either the chemical’s Safety Data Sheet or a list of hazardous chemicals grouped by hazard category to the SERC, the LEPC, and the local fire department (40 CFR 370.30–370.33). It is a one-time submission per chemical. A revised SDS is due within three months of discovering significant new information, and an SDS requested by the LEPC is due within 30 days.
What §311 requires
EPCRA has two hazardous chemical inventory requirements. Section 312 is the annual Tier II report. Section 311 is the SDS reporting requirement: a one-time notice that a hazardous chemical is present at or above threshold, sent so that local planners and responders know what is on site and what its hazards are (40 CFR 370.20). A facility subject to Part 370 must comply with both.
The same thresholds apply to both sections: 10,000 pounds for most hazardous chemicals, and 500 pounds or the Threshold Planning Quantity, whichever is lower, for Extremely Hazardous Substances, present at any one time (40 CFR 370.10). The full threshold table is in Tier II reporting.
When the three-month clock starts
The submission is due “within three (3) months after you first become subject to the reporting requirements of this part” (40 CFR 370.33(a)). The statute uses the same period: three months after the owner or operator is required to have the SDS for the chemical (42 U.S.C. 11021(d)(1)). For a facility that is already reporting, a new chemical becomes subject when it is first present at or above its threshold. EPA’s answer on updates says that an update must be submitted within three months whenever an unreported hazardous chemical is present above the reporting threshold.
Common triggers:
- A new product arrives and its quantity on hand reaches the threshold.
- A product already on site is stocked more heavily, for example a bulk delivery that pushes a solvent past 10,000 pounds for the first time.
- An existing product turns out to contain an EHS that, totaled across mixtures, reaches 500 pounds or its TPQ.
The regulation says “three months,” not 90 days. If you track it as 90 days, note that three calendar months can be as short as 89 days (February 1 to May 1), so use whichever date comes first. Start the clock on the date the threshold was first reached, not the date someone noticed. That makes daily or per-transaction inventory totals worth having: a quarterly count can discover a crossing that is already weeks old.
SDS or list: the two ways to comply
You may meet §311 by either of two methods (40 CFR 370.30(a)):
- Submit the SDS for each hazardous chemical at or above its threshold.
- Submit a list of those hazardous chemicals, grouped by the specific health and physical hazards listed in Section 2 of their SDSs, with the chemical or common name as shown on the SDS. The statute adds that the list must include any hazardous component of each chemical as provided on the SDS (42 U.S.C. 11021(a)(2)(A)(iii)).
If you submit a list, the LEPC can ask for the SDS of any chemical on it. You then have 30 days from the request to send it (40 CFR 370.30(b) and 370.33(c)). For mixtures, you may submit the SDS for the mixture or for each hazardous component, but the choice must match how you report that mixture on Tier II, unless that is not possible (40 CFR 370.14(b)). See mixtures in Tier II.
Who receives it
The SDS or list goes to the same three recipients as Tier II: the LEPC, the SERC, and the fire department with jurisdiction over the facility (40 CFR 370.32(a)). EPCRA §311 and §312 are implemented mainly by the SERCs, LEPCs, and fire departments, and EPA’s guidance points facilities to their state for submission procedures. Ask the SERC whether §311 notices go through the state Tier II system or separately.
Updates: significant new information and new chemicals
Section 311 is a one-time requirement per chemical, but 40 CFR 370.31 lists three situations that require more:
| Situation | What to send | Deadline |
|---|---|---|
| Significant new information discovered about a chemical whose SDS you submitted | Revised SDS | 3 months after discovery |
| A new hazardous chemical becomes subject | SDS, or the list described in 370.30(a) | 3 months |
| LEPC requests an SDS not yet submitted | SDS | 30 days after request |
The regulation does not define “significant new information.” EPA has given two pieces of guidance on it. In an older answer, EPA said the duty to resubmit a revised SDS applies to facilities that originally submitted SDSs rather than a list, and that a revised SDS in the new format with no change in hazard classification should be checked with the state. In its 2026 guidance on the new hazard categories, EPA says that significant new information includes the reclassification or addition of any hazard category, and that list filers must then provide updated lists for those chemicals, using the new EPCRA hazard categories, to the SERC, LEPC, and fire department.
The 2026 hazard category rule and §311 lists
EPA’s final rule of June 22, 2026 (91 FR 37022) replaced the EPCRA hazard categories with the OSHA hazard classes and categories as reported in Section 2 of the SDS. The compliance date is January 1, 2028. EPA’s guidance states that use of the updated hazard categories is required for §311 list submissions by January 1, 2028. If you submit a list, expect to regroup it under the new categories. Suppliers are reissuing SDSs under OSHA’s 2024 Hazard Communication amendments, and each changed classification is a potential update under §370.31(a).
How §311 relates to Tier II
| EPCRA §311 | EPCRA §312 (Tier II) | |
|---|---|---|
| What | SDS or list of hazardous chemicals | Inventory: amounts, locations, storage, hazards |
| When | Within 3 months of first reaching threshold; updates as above | Every year by March 1 for the prior calendar year |
| Thresholds | Same for both: 40 CFR 370.10 | |
| Recipients | Same for both: SERC, LEPC, fire department | |
| Regulation | 40 CFR 370.30–370.33 | 40 CFR 370.40–370.45 |
A chemical that crosses its threshold in, say, May 2027 needs a §311 notice by August 2027 and then appears on the calendar year 2027 Tier II report due March 1, 2028. Filing the next Tier II does not satisfy the earlier §311 deadline.
Worked example
On April 14, a plant receives two totes of a cleaning product whose SDS lists an EHS component. Before the delivery, the site held 380 lb of that EHS across other products. The totes add 160 lb at the upper bound of the SDS range, bringing the site to 540 lb. The EHS has a TPQ of 1,000 lb, so its threshold under 40 CFR 370.10 is 500 lb. The site first became subject for this chemical on April 14. The §311 SDS or list update is due by July 14. The chemical goes on the calendar-year Tier II report due the following March 1. At 540 lb it is below the 1,000-lb TPQ, so no §302 notice is triggered.
Common questions
What is the EPCRA 311 deadline?
Within three months after the facility first becomes subject, which is when a hazardous chemical is first present at or above its reporting threshold (40 CFR 370.33(a)). A revised SDS is due within three months of discovering significant new information, and an SDS requested by the LEPC is due within 30 days.
Is EPCRA 311 a one-time or annual requirement?
One-time for each chemical, with updates when significant new information is discovered, when a new hazardous chemical becomes subject, or when the LEPC requests an SDS. The annual requirement is the Tier II report under section 312.
Do I send the SDS or a list?
Either. You may submit the SDS for each chemical at or above threshold, or a list of those chemicals grouped by the health and physical hazards in Section 2 of their SDSs (40 CFR 370.30(a)). If you send a list, the LEPC may request any SDS, due within 30 days.
Who receives the EPCRA 311 submission?
The Local Emergency Planning Committee, the State Emergency Response Commission, and the fire department with jurisdiction over the facility (40 CFR 370.32).
I have seen a 30-day deadline for section 311. Which is right?
The regulation (40 CFR 370.33(a)) and the statute (42 U.S.C. 11021(d)) both give three months for the initial submission and for revised SDSs. The 30-day period in the regulation applies to an SDS the LEPC requests. One EPA general guidance page summarizes the initial deadline as 30 days, which does not match the regulation text. Check whether your state sets a shorter deadline.
Where Chemsana fits
When a receipt pushes a chemical’s CAS total to its threshold for the first time, Chemsana raises an EPCRA 311 alert with the 90-day deadline and sends reminders until it is marked done. See filing and alerts.
Sources
- 40 CFR Part 370 (§§370.10, 370.14, 370.20, 370.30–370.33), eCFR, accessed October 2026.
- 42 U.S.C. 11021, Material safety data sheets, U.S. Code via govinfo.gov, accessed October 2026.
- 91 FR 37022 (June 22, 2026), EPCRA hazard categories final rule, Federal Register.
- Revisions to Hazard Categories and Reporting Guidance, EPA, accessed October 2026.
- Updates for 311 MSDS reporting, EPA frequent question, accessed October 2026.
- Resubmitting revised SDSs based on OSHA’s new Hazard Communication Standards, EPA frequent question, accessed October 2026.
- EPCRA Hazardous Chemical Inventory Reporting: General Reporting Guidance, EPA, accessed October 2026.
This guide summarizes federal requirements for general information. States can set lower thresholds or extra requirements, and it is not legal advice. Confirm obligations with your SERC, LEPC, or a qualified EHS professional.