Does Your Facility Need a CalARP Plan? Regulated Substances & Threshold Quantities
If your facility stores or uses certain hazardous chemicals above a state-set quantity, California requires you to prepare a CalARP plan (also called an RMP, or Risk Management Plan).
If your facility stores or uses certain hazardous chemicals above a state-set quantity, California requires you to prepare a CalARP plan (also called an RMP, or Risk Management Plan). The two terms get used interchangeably. If the triggering substance appears on the federal lists (Table 1 or Table 2), federal RMP requirements may also apply. If coverage is based only on a Table 3 substance or a California-specific lower threshold, the facility may be subject to CalARP without being federally covered for that substance. Most clients first hear about it from their local administering agency. That agency may be a CUPA (Certified Unified Program Agency, often a county environmental health department or fire department), or another participating agency, depending on the jurisdiction.
The trigger isn’t whether a chemical is “dangerous.” It’s whether a specific regulated substance is present at or above its threshold quantity in any single process at the facility. If the answer is yes, you need a plan. If the answer is no, you don’t, but the question is worth documenting in writing.
For a broader overview of the program, see our CalARP and Risk Management Plan compliance in California guide. This piece focuses on the applicability question itself: which chemicals count, how the threshold is measured, and where facilities most often get it wrong.
The Four-Part Applicability Test
CalARP applicability comes down to four questions. All four have to be yes.
Is the chemical on a regulated-substances list?
California’s list of regulated substances and threshold quantities lives at Title 19 CCR §5130.6 (renumbered from §2770.5 in 2024). It contains three tables.
Is it present at the facility above the threshold quantity?
Threshold quantities are listed in pounds. CalARP-specific thresholds are often lower than the federal RMP thresholds for the same chemical.
Is it in a single “process”?
The threshold applies to the maximum amount in any one process, not the total at the site. We’ll come back to this.
Does any concentration qualifier apply?
Some chemicals only count above a certain concentration, or in certain physical forms. This catches many California facilities off guard, in both directions.
If you answer yes to all four, the facility is covered, the program level (1, 2, or 3) is determined by the chemical, accident history, and offsite consequence distance, and a plan is required.
The Three Lists of Regulated Substances
Title 19 CCR §5130.6 organizes regulated substances into three tables. A facility can trigger CalARP through any one of them.
| Table | What it lists | Federal or California | Example chemicals |
|---|---|---|---|
| Table 1 | Regulated toxic substances and threshold quantities | Federal (from 40 CFR Part 68) | Chlorine, anhydrous ammonia, hydrofluoric acid, sulfur dioxide, hydrogen chloride |
| Table 2 | Regulated flammable substances and threshold quantities | Federal (from 40 CFR Part 68) | Propane, butane, isobutane, hydrogen, methane |
| Table 3 | State-regulated substances and threshold quantities | California-specific | Anhydrous and aqueous ammonia (with lower thresholds than federal), additional toxics and reactives that California regulates beyond the federal list |
A facility can be required to file a plan under federal RMP without being subject to CalARP. However, the reverse is not always true: if CalARP applies because of a Table 1 or Table 2 substance, federal RMP also applies. If a facility triggers CalARP only through a Table 3 substance or a California-specific lower threshold, it may not have a corresponding federal RMP obligation for that substance. In practice, the California list is where most facilities first cross a line, because California sets lower thresholds for several common chemicals than the federal rule does.
The verticals that show up most often in our work:
- Refrigerated warehouses, cold storage, food processors with anhydrous or aqueous ammonia refrigeration systems.
- Water and wastewater treatment plants using chlorine, sulfur dioxide, or anhydrous ammonia.
- Metal finishers, platers, electronics manufacturers, ceramics producers using nitric acid, hydrofluoric acid, hydrogen chloride, or cyanide compounds.
- Chemical distributors and specialty manufacturers with mixed inventories that creep across thresholds as product lines change.
The “Single Process” Rule
This is where applicability questions most often go sideways.
The threshold quantity applies to the maximum amount of a regulated substance that could be present in any one “process” at the facility, not the total inventory across the site. A process includes any tank, vessel, piping, or interconnected equipment where the chemical is stored, used, or transferred. Two storage tanks plumbed together are one process. Two separate tanks with no interconnection, and physically far enough apart that a release from one wouldn’t involve the other, are usually two processes.
When we walk a facility, the first thing we check on the applicability question is the maximum quantity in any one process unit. A site that holds 1,200 pounds of anhydrous ammonia across two unconnected refrigeration systems looks very different on the threshold test than a site that holds the same 1,200 pounds in one connected system. The total inventory number on the HMBP (Hazardous Materials Business Plan) or CERS (the state’s online environmental reporting portal) submittal isn’t the right number for the CalARP test, even though most facilities reach for it first.
This is also why facility changes can quietly trigger CalARP without anyone noticing. A new tank, a process tie-in, a relocation that puts two previously separate vessels close enough to share a release scenario, any of these can push a single process over the threshold without changing the total chemical inventory at the site.
Common Applicability Gotchas
A few patterns we see repeatedly during applicability reviews:
- Aqueous ammonia at lower concentrations may not count. California regulates aqueous ammonia, but a concentration qualifier in Table 3 narrows what triggers a plan. The concentration on your SDS (Safety Data Sheet) matters as much as the volume in the tank.
- Nitric and sulfuric acid only count under certain conditions. Both appear on the federal regulated list, but the threshold often doesn’t apply at the concentrations most California metal finishers and electronics manufacturers actually use. Same chemical, same tank, different applicability outcome depending on what’s on the SDS.
- Federal RMP without CalARP is possible. A facility may exceed a federal threshold for a flammable substance (propane is the most common) and trigger federal RMP filing without crossing any state-specific threshold.
- The inventory you report on CERS isn’t the inventory the CalARP test uses. CERS reports facility-wide quantities. CalARP measures the maximum in a single process. These are two different numbers.
- “We thought we weren’t covered.” This is what we hear most often when a CUPA inspection or violation letter arrives. A previous determination was done years ago, inventory has drifted up since, and no one re-ran the threshold check. The applicability question is not a one-time question.
When the Answer Is “We Need to Check”
If a chemical on your inventory looks close to a threshold, or if your operation has changed since the last regulatory review, the practical next step is a written applicability determination. CDMS does this two ways:
Standalone applicability review.
We evaluate your chemicals, quantities, processes, and concentration qualifiers against Title 19 CCR §5130.6 and the federal regulated lists. If you’re not covered, we issue an applicability letter that documents the determination and the rationale, which is useful regulatory proof the next time the administering agency asks.
Ongoing determination within Comprehensive Compliance Management.
For clients on our Comprehensive Compliance Management program, CalARP applicability is checked continuously against the chemical inventory we maintain for your site. When a quantity change pushes a process toward a threshold, you hear about it before the CUPA does.
If the determination comes back positive, the next questions become program level and what’s actually in the plan. See What’s Inside a CalARP/RMP Submittal for the contents of a complete plan and what your team supplies versus what we assemble.
Trusted throughout California
BSY started working with CDMS last year after our in-house EHS person departed the company. CDMS reviewed our existing operational permits as well as any additional Federal, State and Local regulations that could apply and helped us to create a comprehensive compliance calendar to track regulatory deadlines and submittal due dates. The CDMS team does an excellent job of tracking everything and can be relied upon to complete the forms accurately and assist with submittals, allowing me to focus on our business.
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Tell us about your facility and your deadline. You’ll get a clear read on what applies and a scoped plan to handle it.