New EPA Tolerance Exemption for Sodium Nitrate Fumigants

The lesson from EPA's June 2026 action on sodium nitrate isn't really about one chemical. It's about what responsible operators accomplish when they engage the tolerance petition process correctly — and what post-harvest operations and pesticide registrants need to understand before that fumigant canister ever fires.

On June 15, 2026, EPA published a final rule in the Federal Register (Document No. 2026-11941) establishing an exemption from the requirement of a tolerance for residues of sodium nitrate (CAS Reg. No. 7631-99-4) when used as an inert ingredient — functioning specifically as a dilutant and oxidizer — in pesticide formulations applied to raw agricultural commodities post-harvest. That exemption is now codified at 40 CFR 180.910 and was effective immediately upon publication.

If you operate a produce warehouse, manage post-harvest fumigation programs, or represent a pesticide registrant navigating inert ingredient classifications, this regulation is directly relevant to your compliance picture. Here's what changed, what it requires, and where the real compliance risks sit.

What Is a Tolerance Exemption, and Why Does It Matter?

Under Section 408 of the Federal Food, Drug, and Cosmetic Act (FFDCA), any pesticide chemical residue present in food must have a legal basis — either a numerical tolerance (a maximum residue level set by EPA) or an exemption from the tolerance requirement. Without one or the other, the food is considered adulterated under federal law. That's not a technicality — it's an enforcement exposure with real commercial consequences.

EPA grants tolerance exemptions when it determines there is reasonable certainty of no harm from aggregate exposure to the residue. Practically, this means EPA has evaluated the substance's toxicological profile, the exposure levels expected from normal use, and the populations at risk — including infants and children — and concluded that a specific numerical limit is unnecessary because the risk is negligible under defined conditions.

What makes this regulatory tool important for the post-harvest sector is what it enables: product developers and registrants can establish a legal basis for novel formulations without commissioning the full residue chemistry studies that a traditional numerical tolerance requires. The tradeoff is that the exemption carries conditions, and those conditions are binding.

Sodium nitrate, under the specific fumigant application AgroFresh petitioned for, now meets that standard. But the scope of the exemption is narrow, and the compliance conditions are worth reading precisely.

The Technology This Exemption Covers

This exemption is not a broad clearance for sodium nitrate in agricultural settings. The operative conditions are specific, and all of them must be present simultaneously:

• Sodium nitrate functions as an inert ingredient — not the pesticidally active compound — in the formulation
• Its role is as a dilutant and oxidizer
• Application is post-harvest only, applied to raw agricultural commodities
• Delivery is through a fumigant canister
• The canister is remotely detonated
• Release occurs inside a sealed warehouse

Each of those conditions is a compliance boundary, not a preference. Use sodium nitrate as an active ingredient, apply it in an unsealed environment, manually trigger the canister, or use it pre-harvest — and this exemption does not apply. You're back to needing either an independently established tolerance or a new regulatory pathway.

AgroFresh Inc. submitted the underlying petition to EPA under FFDCA Section 408(d), seeking this exemption for a fumigant technology in development for post-harvest produce protection. AgroFresh is a significant operator in the post-harvest space, well known for its SmartFresh (1-methylcyclopropene) platform, and their petition reflects the kind of forward regulatory engagement that creates a clear market pathway without post-launch legal exposure. EPA evaluated the petition, determined the conditions created a well-characterized and controlled exposure scenario, and granted the exemption.

Citation hook: Under 40 CFR 180.910, effective June 15, 2026, sodium nitrate (CAS Reg. No. 7631-99-4) is exempt from pesticide residue tolerance requirements when used exclusively as an inert dilutant and oxidizer in a remotely detonated fumigant canister released inside a sealed post-harvest warehouse.

The Regulatory Framework: How 40 CFR 180.910 Works

40 CFR Part 180 is the regulatory home for pesticide tolerances and exemptions under FFDCA. Within that part, § 180.910 specifically lists inert ingredients that are exempt from the tolerance requirement when applied to raw agricultural commodities after harvest. Adding sodium nitrate to that list — under the defined conditions — is the core of what EPA did here.

The petition process under FFDCA Section 408(d) requires the petitioner to demonstrate that the proposed exemption meets the safety standard in Section 408(b)(2): reasonable certainty of no harm to the U.S. population from aggregate exposure, including dietary exposure and all other relevant exposure pathways. EPA also considers the specifics of how the product is applied. In this case, the sealed warehouse and remote detonation conditions substantially limit human exposure during fumigation — a factor that clearly supported EPA's safety finding.

EPA processes dozens of tolerance and exemption actions under FFDCA Section 408 each year. The 40 CFR 180.910 list now includes hundreds of inert ingredients with established exemptions, each built through petitions like AgroFresh's — establishing safety findings that allow specific formulations to operate without a numerical residue limit. This is an underused pathway for smaller registrants, and AgroFresh's successful petition is a useful reference point for what it looks like when it's done right.

Before and After: What This Rule Actually Changed

The practical effect: AgroFresh's fumigant product — and any other pesticide formulation that meets all of these conditions exactly — now has a legal basis for post-harvest warehouse use without generating a tolerance violation under FFDCA.

Compliance Guidance for Post-Harvest Operations

If post-harvest fumigation is part of your operation, here's where to focus your compliance attention in light of this rule.

Verify the product meets the exemption conditions. An exemption at 40 CFR 180.910 applies only when sodium nitrate functions as an inert ingredient — not the active ingredient. Your vendor should be able to document that the product's EPA registration reflects this classification. If you're using a sodium-nitrate-containing fumigant and you're not certain of its inert classification, get that documentation before the next application cycle.

Confirm your warehouse meets the "sealed" standard. EPA's exemption requires release inside a sealed warehouse, and that's a functional standard, not a construction specification. A warehouse with gaps in the building envelope, open ventilation pathways, or connected occupied spaces during fumigation likely doesn't qualify. Assess the physical conditions of your facility honestly — and document that assessment.

Remote detonation is a hard requirement. If your protocol allows workers to manually trigger the canister or be present at the point of detonation, you have a compliance gap under this exemption and almost certainly under OSHA's fumigation worker safety standards as well. Remote detonation is both the legal condition for the exemption and the safety baseline for the application method.

Apply this exemption to post-harvest commodity, not processed product. The exemption covers raw agricultural commodities. If your operation processes commodities prior to or concurrent with fumigation — washing, packing, cutting, or any transformation that changes the commodity's regulatory classification — verify that the product at the time of fumigation still qualifies as a raw agricultural commodity under FDA's definitions.

Keep application records. Any pesticide use relying on a tolerance exemption rather than a numerical tolerance warrants documentation. Record the product name, EPA registration number, application date, facility location, the commodity treated, and the specific exemption conditions you relied on. If an FDA inspection or state pesticide residue audit arises, those records demonstrate the application fell squarely within the exemption's scope.

Citation hook: Post-harvest operators relying on the 40 CFR 180.910 exemption for sodium nitrate must satisfy all six application conditions simultaneously — inert ingredient classification, dilutant/oxidizer function, post-harvest timing, raw agricultural commodity, sealed warehouse, and remote detonation — because any deviation eliminates the exemption's legal protection.

For Pesticide Registrants: What This Petition Illustrates

In my view, the more valuable lesson here is about regulatory strategy, not just compliance fact.

AgroFresh identified a formulation approach — sodium nitrate as an oxidizer and dilutant in a remotely detonated fumigant canister — and recognized early that they needed a clear legal pathway before launch. They filed a Section 408(d) petition. EPA evaluated it against the Section 408(b)(2) safety standard. The exemption was granted. The product has a market pathway.

That's the process working correctly. The alternative — launching a product containing an ingredient without an established tolerance or exemption and hoping for enforcement discretion — is a risk profile that rarely serves operators well. FDA and state pesticide enforcement programs do conduct post-harvest residue monitoring, and a commodity found to contain a residue without a legal basis generates adulteration findings that are expensive to unwind.

The FFDCA Section 408(d) petition process is genuinely underused by smaller registrants, and I think that's partly because the tolerance framework feels like FDA's territory when it's actually EPA's jurisdiction for pesticide residues. If you're developing a pesticide formulation with novel inert ingredients and you don't have an established tolerance exemption for each of them, the petition process deserves a serious look before you're in market.

Other Regulatory Obligations That Remain

A tolerance exemption removes one compliance obligation. It doesn't remove others. For operations using this fumigant product, the following remain fully in force:

• FIFRA registration: The product must still be registered under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) before sale or distribution. The 40 CFR 180.910 exemption addresses the FFDCA food residue pathway, not the FIFRA registration requirement.
• Pesticide label compliance: Pesticide labels are legal documents. Application must comply exactly with the registered label's directions. The conditions in the exemption should be reflected in and consistent with the product's label.
• Worker safety standards: EPA's Agricultural Worker Protection Standard (40 CFR Part 170) and applicable OSHA fumigation safety requirements apply regardless of tolerance status. Remote detonation isn't just a legal condition for the exemption — it's the foundation of the worker safety protocol.
• State registration: Most states have independent pesticide registration requirements. Federal exemption from a tolerance requirement does not automatically satisfy state-level registration demands.
• Applicator recordkeeping: Commercial applicators are subject to state recordkeeping requirements and, depending on certification status, federal requirements under 40 CFR Part 171.

Effective Date and Recommended Next Steps

The rule was effective June 15, 2026 — the Federal Register publication date. There is no phase-in period. Products formulated to meet the exemption conditions can rely on 40 CFR 180.910 for sodium nitrate's inert ingredient status as of that date.

If you are currently using any post-harvest fumigation products containing sodium nitrate and have been doing so without a verified tolerance or established exemption, assess your compliance position now. The right path forward depends on what exemptions existed prior to this rule and whether your historical applications matched any available exemption conditions.

At Certify Consulting, we've guided post-harvest operations and pesticide registrants through tolerance and exemption compliance assessments across more than 200 client engagements — and in eight years of work in this space, the pattern I see most consistently is that uncertainty about a regulatory basis accumulates risk quietly until an inspection or audit forces the question under pressure. That's the situation to avoid. If your fumigation program's regulatory basis isn't clearly documented, this is a reasonable moment to sort it out — before the next application cycle, not after.

For registrants navigating the petition process, our regulatory consulting services include petition preparation support and inert ingredient classification analysis.

Broader Context: Why Inert Ingredient Oversight Is Tightening

Historically, inert ingredients in pesticide formulations received substantially less regulatory scrutiny than active ingredients. That's been changing for roughly a decade, driven by toxicology research that found certain "inert" ingredients were not without biological activity, and by stakeholder pressure on EPA to close what critics described as a gap between the classification and the risk.

Post-harvest applications face particular scrutiny in this environment because the time between application and consumption is compressed. A post-harvest fumigation of produce destined for retail shelves has far less dissipation time than a pre-harvest field application. EPA's interest in the sealed warehouse and remote detonation conditions for the sodium nitrate exemption reflects exactly that concern — those conditions create a controlled, characterized exposure scenario rather than an open-environment one, and that characterization was material to the safety finding.

The sodium nitrate exemption, granted with specific conditions attached, is consistent with the pattern I'd expect EPA to continue applying to future inert ingredient petitions in post-harvest contexts: yes to specific, well-characterized uses; significantly more scrutiny to broader or less-controlled applications. That's the model. Registrants developing post-harvest fumigant products would do well to design their applications with that scrutiny in mind from the start.

Frequently Asked Questions

What is a tolerance exemption under 40 CFR 180.910?

A tolerance exemption at 40 CFR 180.910 is EPA's determination that a specific inert ingredient in a pesticide formulation does not require a numerical maximum residue limit (tolerance) when applied to raw agricultural commodities post-harvest. EPA grants these exemptions when aggregate exposure to the ingredient meets the "reasonable certainty of no harm" safety standard under FFDCA Section 408(b)(2). Hundreds of inert ingredients are currently listed at 40 CFR 180.910 with established exemptions.

Who benefits from the June 15, 2026 sodium nitrate tolerance exemption?

The immediate beneficiary is AgroFresh Inc., which petitioned for the exemption to support a post-harvest fumigant product under development. More broadly, any pesticide registrant whose product formulation uses sodium nitrate (CAS Reg. No. 7631-99-4) as an inert dilutant/oxidizer in a remotely detonated fumigant canister for sealed warehouse post-harvest applications now has a clear regulatory pathway under 40 CFR 180.910.

What conditions must be met to rely on this sodium nitrate exemption?

All six conditions must be met simultaneously: (1) sodium nitrate is classified as an inert ingredient, not the active ingredient; (2) it functions as a dilutant and oxidizer; (3) application is post-harvest; (4) the commodity treated is a raw agricultural commodity; (5) the canister is remotely detonated; and (6) release occurs inside a sealed warehouse. Any deviation from these conditions removes the exemption's protection.

Does this exemption apply to all post-harvest uses of sodium nitrate?

No. The exemption is specifically limited to sodium nitrate used as an inert ingredient in a fumigant canister that is remotely detonated and released inside a sealed warehouse. Pre-harvest applications, open-environment applications, manual detonation, use on processed commodities, and use as an active ingredient are all outside the scope of this exemption.

What other regulations apply even with the tolerance exemption in place?

The tolerance exemption addresses only the FFDCA food residue requirement. FIFRA registration, pesticide label compliance, EPA's Agricultural Worker Protection Standard (40 CFR Part 170), OSHA fumigation safety requirements, state pesticide registration, and applicator recordkeeping requirements all remain in full force regardless of tolerance status.

Last updated: 2026-06-25