How to screen a new chemical before purchase against EPCRA, RMP, and PSM thresholds

Why screen before the purchase order

Most of the federal triggers covered here start a clock the day a quantity is reached, not the day someone notices. A first crossing of a Tier II threshold starts a three-month §311 deadline (40 CFR 370.33). A first crossing of an EHS threshold planning quantity starts a 60-day §302 deadline (40 CFR 355.20). The first time a regulated substance is above its threshold in a process is the deadline for an initial RMP (40 CFR 68.150(b)), and the same event in an already covered process requires an RMP update (68.190(b)(3)). PSM requires written management of change procedures for changes to process chemicals in a covered process, addressed before the change (29 CFR 1910.119(l)). Screening at the request stage is the only point where all of these can be planned for, or avoided by changing the order.

The checklist at a glance

1. Get the current SDS before anything else

Ask the supplier for the SDS of the exact product and grade being quoted. Chemical manufacturers and importers must obtain or develop an SDS for each hazardous chemical they produce or import, and employers must have one in the workplace for each hazardous chemical they use (29 CFR 1910.1200(g)(1)). Three sections drive the screen:

• Section 2, hazard identification: the hazard classes and categories, which become the EPCRA hazard categories on Tier II.
• Section 3, composition: the CAS number and concentration, or concentration range, of each classified ingredient.
• Section 9, physical and chemical properties: density or relative density, and flash point.

If Section 3 withholds an identity or uses a wide range, ask the supplier whether the product contains anything on the lists in step 2 and at what maximum concentration, and keep the answer in writing.

2. Check every CAS number against the federal lists

• EPCRA Extremely Hazardous Substances, 40 CFR Part 355, Appendices A and B: TPQ and EHS RQ.
• CERCLA hazardous substances, Table 302.4: reportable quantity for spills.
• TRI toxic chemicals, 40 CFR 372.65, and the lower-threshold chemicals in 372.28.
• RMP regulated substances, 40 CFR 68.130, Tables 1 to 4: threshold quantity per process.
• OSHA PSM, 29 CFR 1910.119 Appendix A, plus the flammable criterion in 1910.119(a)(1)(ii): a Category 1 flammable gas, or a flammable liquid with flash point below 100 °F, at 10,000 lb or more on site in one location.
• RCRA, 40 CFR 261.33(e) and (f): commercial chemical products that become acute (P) or toxic (U) hazardous waste when discarded unused.

EPA’s Consolidated List of Lists gathers the EPCRA, CERCLA, and CAA §112(r) lists in one place. EPA describes it as a reference tool, not a definitive source of compliance information, so confirm any hit against the regulation itself. Every product with an SDS-listed hazard is also an OSHA hazardous chemical for Tier II purposes, whether or not it appears on any list.

3. Compute the projected site total by component

The number that matters is the site total once the order arrives. For each CAS number:

• Start from the current maximum on hand for that CAS, across all products and locations.
• Add the largest amount of the new product that will be on site at once. For a product delivered in one shipment, that is the full order; for one replenished on a schedule, it is the peak.
• Convert gallons to pounds with the product’s density (see gallons to pounds).
• Multiply by the weight percent, using the upper bound of any range. EPA’s guidance for EPCRA §§302, 304, and 311/312 is to use the upper bound when the SDS gives only a range (see mixtures in Tier II).
• Skip a component only where the regulation allows it: at or below 1% (0.1% for carcinogens) for Tier II, at or below 1% for an EHS under §302, below 1% under RMP.

4. Compare against each threshold

Tier II and §302 compare the facility-wide total with 10,000 lb, with 500 lb or the TPQ for an EHS, and with the TPQ (Tier II reporting; EPCRA 302 EHS and TPQs). RMP and PSM compare the quantity in a process, so ask where the chemical will be stored and used and whether that vessel is connected to, or near, others holding the same substance. The thresholds comparison sets out how each program measures. Note the margin as well as the result: a total at 470 lb against a 500-lb threshold will be crossed by the next order.

5. Check storage and fire code limits

Where a jurisdiction has adopted the International Fire Code, it limits hazardous materials by maximum allowable quantity (MAQ) per control area, in IFC Tables 5003.1.1(1) and 5003.1.1(2). Identify the new product’s fire code hazard classification and add its quantity to what is already in the control area where it will be stored or used, then compare the total with the MAQ for that classification. Your fire marshal or building official is the authority on which code edition applies. Storage compatibility with nearby materials, such as keeping oxidizers away from flammables, belongs in the same review.

6. Check site permits

Air permits can limit emissions of specific pollutants or the amount of certain materials used. Wastewater or pretreatment permits can restrict what may go to drain. Some site permits list approved raw materials. Read each active permit for conditions the new product would touch, such as a VOC limit for a coating or a discharge limit for a metal, and note the permit and condition number in the approval record.

7. Check TRI and RCRA implications

TRI. If any component is a TRI chemical and the site is a covered facility, estimate annual use, not inventory. A covered facility reports when it manufactures or processes more than 25,000 lb, or otherwise uses more than 10,000 lb, of the chemical in a calendar year (40 CFR 372.25), with lower thresholds for the chemicals in 372.28. Concentrations below 1% (0.1% for carcinogens) can be excluded (372.38(a)). Add the new product’s projected use to existing use of the same chemical.

RCRA. Decide now how leftovers, residues, and spent material will be managed. An unused product whose generic name is listed in 261.33(e) or (f) becomes a P- or U-listed hazardous waste when discarded, and a spent product may be hazardous by characteristic (ignitability, corrosivity, reactivity, or toxicity under 261.21–261.24). New waste counts toward the site’s monthly generator category. Under 40 CFR 260.10, a site generating more than 1 kg (2.2 lb) of acute hazardous waste in a calendar month is a large quantity generator, so discarding a single container holding more than 1 kg of a P-listed product can change a site’s status for that month.

8. Decide, set conditions, and record it

Three outcomes cover most requests:

• Approve when no threshold, limit, or permit condition is reached and none is close.
• Approve with conditions when the product is acceptable under limits: a maximum quantity on hand, a storage location, a container size, a sunset date, or a substitution review. Conditions only work if receiving and storage know them.
• Decline when the product would put the site into a program it is not prepared for, or exceed a fire code or permit limit, and a substitute exists.

For the record, keep: the request and requester; the SDS and its revision date; each CAS checked and the lists it appeared on; the projected totals with units, densities, and the concentration bound used; each threshold compared, with its citation; the decision, conditions, approver, and date. That file answers the auditor’s question of why a chemical was allowed in, and it is the starting point for the §311 notice if a threshold is later crossed.

Common questions

Where Chemsana fits

Chemsana runs chemical approval requests through this screen. It extracts composition, density, and flash point from the SDS, projects the site total by CAS number at the upper bound, checks EPCRA 302, CAA 112(r), OSHA PSM, CERCLA RQ, TRI, and RCRA lists, site permits, and IFC maximum allowable quantities by control area, and records the approve, approve with conditions, or decline decision with the citations and math. See intake decisions.

Sources

1. 29 CFR 1910.119, Process safety management (paragraphs (a) and (l), Appendix A), eCFR, accessed October 2026.
2. 29 CFR 1910.1200, Hazard communication, eCFR, and Appendix D, OSHA, accessed October 2026.
3. 40 CFR Part 355 and Part 370, eCFR, accessed October 2026.
4. 40 CFR Part 68 (§§68.115, 68.130, 68.150, 68.190), eCFR, accessed October 2026.
5. 40 CFR Part 302 (Table 302.4), eCFR, accessed October 2026.
6. 40 CFR Part 372 (§§372.25, 372.28, 372.38, 372.65), eCFR, accessed October 2026.
7. 40 CFR 260.10, generator definitions and 40 CFR 261.33, discarded commercial chemical products, eCFR, accessed October 2026.
8. Consolidated List of Lists, EPA, accessed October 2026.
9. Code Corner: 2024 IFC Tables 5003.1.1(1) and 5003.1.1(2), Maximum Allowable Quantities, International Code Council, 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.