How to Choose a Compliant Fuel Biocide Under EU BPR
Choosing a fuel biocide has never been a trivial decision, but the stakes have risen. Under the EU Biocidal Products Regulation (EU) 528/2012, actives classified as carcinogenic are excluded from approval - and one widely used marine diesel-biocide active carries exactly that classification. For operators who have relied on a single treatment for years, the question is no longer just "does it work?" but "will it still be available and legal next procurement cycle, and the one after that?"
This article sets out what "compliant" actually means under the current regulatory framework, the six criteria that a future-proofed biocide selection must satisfy, and how Fuelcare's FuelClear™ M15 is built to meet them. It is part of our complete guide to fuel biocides and EU regulation.
What "compliant" means under the EU Biocidal Products Regulation
The BPR (Regulation (EU) 528/2012) is the legal framework governing which active substances may be placed on the market and used in biocidal products across the European Union. Fuel biocides fall under Product Type 6 (PT6): preservatives for products during storage. Before a biocide product can legally be sold or used in the EU for this application, its active substance must be approved under the BPR, and the product itself must be authorised.
The BPR contains hard exclusion criteria. Under Article 5, active substances classified as carcinogenic, mutagenic or toxic for reproduction (CMR) category 1A or 1B shall not be approved. This is not a risk-based assessment where high efficacy could offset a classification - it is an exclusion. A product whose active substance carries a harmonised carcinogen Cat 1A/1B classification will not survive the approval process intact, and products already on the market built on such actives face withdrawal once the review programme concludes.
A widely used marine diesel-biocide active is classified carcinogenic Cat 1B. That classification, combined with the Article 5 exclusion, means compliance risk is real - not theoretical. Operators continuing to procure on habit, without checking their treatment against current ECHA decisions, are exposed.
The six criteria for a future-proofed biocide selection
Selecting a compliant, future-proofed fuel biocide requires satisfying six criteria. They build on each other: a product that fails the first criterion cannot be made compliant by passing the rest.
1. Non-CMR active substance
The active substance must not be classified carcinogenic, mutagenic or toxic for reproduction at category 1A or 1B under Regulation (EC) 1272/2008 (CLP). This is the Article 5 threshold.
FuelClear™ M15 is built on C(M)IT/MIT - 5-chloro-2-methyl-3(2H)-isothiazolone and 2-methyl-3(2H)-isothiazolone in a 3:1 ratio. Independent toxicological assessments - including a two-year rat drinking-water study and a thirty-month dermal carcinogenicity study in mice - found no treatment-related neoplasms at any dose, concluding the active is non-carcinogenic. The active is not classified carcinogenic, and therefore does not trigger the Article 5 exclusion.
An honest handling note belongs here: non-carcinogenic does not mean hazard-free. C(M)IT/MIT is a professional-use biocide - it is irritating to skin, can cause serious eye damage and is a known skin sensitiser. It requires correct handling and must be dosed per the supplier's technical guidance. The advantage over a CMR-classified active is regulatory, not a claim that handling requirements disappear.
2. BPR Product Type 6 approval
The active substance must be approved specifically for PT6 use. C(M)IT/MIT (3:1) was approved for Product Type 6 (fuel preservation) under Commission Implementing Regulation (EU) 2016/131. This means the active has passed the peer review and approval process administered by ECHA's Biocidal Products Committee, and the product built on it can be authorised for legal use in the EU as a fuel preservative.
Always verify BPR approval status directly against ECHA's published list of approved active substances - not solely on supplier claims - before procurement.
3. Efficacy in the water phase, not just the fuel phase
Microbial contamination - the "diesel bug" - lives at the interface between water and fuel, not in the fuel itself. An active that partitions only into the fuel phase or is deactivated by water will not reach the colony where it lives. For a biocide to work in a real contaminated tank, it must be present in both the fuel and the water phase.
C(M)IT/MIT is not deactivated by water, and its partitioning characteristics mean it is active in both phases - eradicating contamination at the fuel-water interface as well as protecting the bulk fuel. This is a technical requirement, not a marketing claim, and it should be verified with the supplier before selection.
4. No adverse effect on EN590 fuel specification
A treatment that works but degrades the fuel's key properties creates a different problem. Cetane number, cold-filter plugging point (CFPP), lubricity, oxidation stability and copper corrosion must all remain within EN590 limits after treatment.
FuelClear™ M15 has been independently tested in EN590 diesel at concentrations far above the recommended dose rate. The results show no impairment of cetane number, cloud point, CFPP, lubricity, copper corrosion or oxidation stability - all properties remained well within EN590 specification. This testing is available on request; operators should ask any biocide supplier for equivalent no-harm data before specification.
5. Proven performance in FAME/biodiesel blends
FAME (fatty acid methyl ester) content in modern European diesel blends is increasing, and biodiesel is more susceptible to microbial attack than mineral diesel - it provides a richer food source for organisms, and it tends to hold more free water. A biocide evaluated only in neat mineral diesel may not perform to the same standard in B7 or higher-blend fuel.
FuelClear™ M15 has been tested in B100 biodiesel and demonstrated equivalent performance, achieving a 99.9% kill at recommended treat rate within seven hours (ASTM E1259-05). Operators specifying treatments for modern blended fuels should ask for documented biodiesel efficacy data, not just efficacy claims.
6. Fast, reliable EU supply
Curative biocide treatment is time-critical. An active contamination problem identified before a vessel sails, or at the start of a seasonal drawdown, cannot wait weeks for an international shipment to clear customs. A product that is technically compliant but routinely unavailable at short notice transfers risk back to the operator.
Supply chain resilience - specifically, the availability of EU stock with documented short lead times - belongs in the evaluation criteria alongside the technical and regulatory tests. Fuelcare holds EU stock at its distribution hub in Venlo, Netherlands, for fast delivery across Europe.
How to apply these criteria at procurement
In practice, a compliant biocide selection requires four pieces of confirmed documentation from the supplier:
- ECHA approval record - the active substance name, the approved product types, and the Commission implementing regulation number confirming PT6 approval.
- CLP hazard classification - confirming the active is not classified CMR Cat 1A/1B under Regulation (EC) 1272/2008.
- EN590 no-harm test data - independent testing results at or above the recommended dose rate.
- Biodiesel efficacy data - efficacy testing in relevant FAME blends.
If a supplier cannot provide these four items, the claim of compliance cannot be verified. Procurement without verification does not protect the operator - it simply defers the exposure.
Future-proofing: looking past the current approval cycle
BPR approvals are time-limited. The review programme is ongoing, and the regulatory direction of travel - reinforced by the EU's chemicals strategy and the sustained pressure on CMR actives - is towards tighter restrictions, not looser ones. An active approved today under conditions that are subsequently revised may face a renewal challenge.
Selecting an active that is not in the restricted category from the outset is the most durable form of future-proofing. It removes the uncertainty of whether a future review will trigger a restriction, and it simplifies procurement governance - no need to track regulatory windows for a classification that does not apply.
What to do next
Evaluate your current treatment against the six criteria above. If you cannot confirm non-CMR active, PT6 approval, water-phase efficacy, EN590 no-harm data and biodiesel performance from your current supplier, the review is overdue.
FuelClear™ M15 is Fuelcare's BPR PT6-approved biocide, built on a non-carcinogenic active (C(M)IT/MIT), with independently verified EN590 and biodiesel performance data. EU stock is held at our Venlo (NL) distribution hub for fast delivery across Europe.
To confirm whether your current treatment is compliant and future-proofed, speak to the Fuelcare team - call +44 (0)1743 360784 or email sales@fuelcare.com.
Frequently asked questions
What is Product Type 6 under the EU Biocidal Products Regulation?
Product Type 6 covers preservatives for products during storage - which includes fuel biocides. An active substance must be specifically approved for PT6 before a biocide product can legally be placed on the EU market for fuel preservation use. Approval status is published and maintained on the ECHA website.
Can a carcinogenic active still be used in a fuel biocide under the BPR?
No - not if it is classified carcinogenic category 1A or 1B. Article 5 of the BPR sets a hard exclusion for CMR Cat 1A/1B actives. They shall not be approved as biocidal active substances. Products built on such actives will be withdrawn from the market once the review programme reaches a conclusion on that active.
Is C(M)IT/MIT (the active in FuelClear™ M15) classified as a carcinogen?
No. Independent studies including a two-year rat drinking-water study and a thirty-month dermal study in mice found no treatment-related neoplasms at any dose. C(M)IT/MIT is documented as non-carcinogenic. It is not classified CMR Cat 1A/1B and therefore does not trigger the BPR Article 5 exclusion.
What documentation should I ask a biocide supplier to provide before procurement?
At minimum: the ECHA approval record confirming active-substance PT6 approval; the CLP hazard classification for the active substance; EN590 no-harm test data; and efficacy testing in biodiesel blends. Without these four items, compliance cannot be verified independently of the supplier's claims.