Anti-Rodent, Anti-Termite and Insecticidal Additives for Plastics: 3 Types, How They Work and What the Evidence Shows

Anti-rodent and anti-termite additives are substances compounded into a plastic so that rodents stop gnawing it or insects stop attacking it, and they come in 3 types: bitterants, capsaicinoids and pyrethroid insecticides. Two of the three deter without killing and one kills, and that difference decides both the claim you may make and the law you fall under. Repellents are row 20 of the 43 additive families covered on this site, and the smallest of them: 4 substances, no published dosage and no standard test method.

The articles at risk are the ones animals reach and can bite: cable and conduit jackets, buried drip irrigation tubing, mulch film and the polyethylene sheets laid under concrete slabs. Termites alone cause about USD 40 billion of global economic impact a year, with subterranean species responsible for about 80 % of it, in the 2022 review by Oi and co-authors published in Insects.

This reference lists what is published about these additives and states plainly where nothing is. Published: the 0.05 ppm bitterness threshold of denatonium benzoate, two peer-reviewed capsaicin composites with measured char and limiting oxygen index values, the field record of termiticide-impregnated barrier sheets, and the EU approval decisions behind permethrin and bifenthrin. Not published in the sources behind this page: any dosage, any service life and any standard gnaw-resistance test for plastics.

The table below compares the 3 types on their example actives, mode of action, target pest, host articles and position under the EU Biocidal Products Regulation.

Product-type is the EU Biocidal Products Regulation category that decides which approvals a treated article needs.

What Are Anti-Rodent and Anti-Termite Additives for Plastics?#

An anti-rodent additive is an aversive substance compounded into a plastic compound or masterbatch so that a rodent that starts to gnaw the article stops, while an anti-termite additive is an insecticide incorporated into a polyethylene film or sheet so that termites attacking it are killed. The aversive route acts on taste and pungency and leaves the animal alive. The insecticidal route acts on the insect nervous system and does not.

Repellents are one of the 43 families of plastic additives on this site, and one of the smallest, sitting in the functional-additive group alongside flame retardants, biodegradation additives and odour-control additives. Neither chemistry reaches the converter as a neat powder: these actives arrive as an additive masterbatch, a concentrate let down into the base resin during compounding or extrusion, which is why the commercial search term is anti-rodent masterbatch rather than anti-rodent chemical.

Repel, Deter or Kill: Three Claims With Three Legal Consequences#

The wording of the claim, not the chemistry, decides the legal route: a product that repels rodents falls under product-type 19, which Annex V of Regulation (EU) No 528/2012 defines as repellents and attractants, including against rodents, while a product that kills termites falls under the insecticide product-type 18. A third route applies where the stated purpose is protecting wood, which is product-type 8. Article 3(1)(l) of the same Regulation defines a treated article as any substance, mixture or article that has been treated with, or intentionally incorporates, one or more biocidal products, so a cable jacket carrying a bitterant is a treated article whatever the marketing says.

Which claim a compounder makes is therefore a regulatory decision taken before the formulation work starts, and both routes end in the same regime for treated articles. The neighbouring family of antimicrobial additives for plastics answers a different question, microbial growth rather than animal attack, under the same Regulation and the same Article 58 duties.

What These Additives Are Not: Sleeving, Armour and Pest-Control Sprays#

Rodent-resistant braided sleeving, steel tape armour and pest-control sprays solve the same problem by other means and are not plastic additives, so they are outside the scope of this page. Sleeving and armour are hardware fitted around a finished cable. Sprays, baits and soil treatments are pest control of buildings, vehicles and gardens, a separate industry with its own registrations. This reference covers only substances compounded into the polymer, and the comparison between the additive route and the hardware route sits at the foot of this page.

Why Rodents and Termites Attack Plastics#

Rodents gnaw plastics because their incisors grow continuously and a cable jacket or a drip tube is a convenient object to wear them down on, while termites attack buried and slab-edge plastics on their way to wood. Rodent damage is mechanical and incidental, so the counter-measure aims at the moment of biting. Termite damage is a by-product of foraging toward cellulose, so the counter-measure aims at the path itself.

What Rodents Gnaw, and Which Articles Are at Risk#

The articles that carry anti-rodent additives are the ones rodents reach and can bite: cable and conduit jackets in PVC, polyethylene and halogen-free EVA or LLDPE compounds, buried drip irrigation tubing, mulch film and outdoor housings. The five article groups recorded in our sources are listed below.

• Cable and conduit compounds, in PVC, PE and halogen-free EVA or LLDPE jacket recipes
• Drip irrigation tubing, buried in soil and within reach of burrowing rodents
• Mulch film and other agricultural films laid on or in the ground
• Outdoor housings and enclosures, where the article sits unattended for years
• Game cartridges, where denatonium benzoate serves a different purpose, deterring swallowing rather than gnawing

The cable case dominates commercial demand, because a gnawed jacket on an energised conductor is a fire and outage risk rather than a cosmetic defect.

What Termites Reach: Buried, Slab-Edge and Barrier Plastics#

Subterranean termites move through soil to reach wood, and a polyethylene sheet laid under a concrete slab sits directly in that path, which is why termiticide-impregnated barrier sheets exist as a product class. The sheet is not protecting itself the way a preservative protects a compound: it occupies the route, and the pyrethroid it carries acts on the insects that try to cross it. Subterranean species account for about 80 % of the roughly USD 40 billion of global termite damage recorded each year by Oi and co-authors in 2022, which is the economic reason the barrier class was developed at all.

3 Types of Anti-Rodent and Anti-Termite Additives#

The 3 types of anti-rodent and anti-termite additives are bitterants, which make the plastic taste intolerable, capsaicinoids, which make it burn, and pyrethroid insecticides, which kill the insect that attacks it. The order runs from mildest to lethal, which is also the order of regulatory burden and the order used in every table and list on this page.

1. Bitterants: Denatonium Benzoate (Bitrex)#

Bitterants are quaternary ammonium compounds that make a surface intolerably bitter, and the only one used in plastics is denatonium benzoate (CAS 3734-33-6), sold as Bitrex, Denatrol, BITTERANT-b and BITTER+PLUS. The substance carries EC number 223-095-2, the formula C28H34N2O3 and a molar mass of 446.6 g/mol, and it is a white odourless solid. Its function in a compound is aversive rather than toxic: an animal that bites the article tastes it and stops. The same substance is added to antifreeze and denatured alcohol outside the plastics industry, and to game cartridges to deter swallowing, a separate purpose from deterring gnawing.

The published number attached to denatonium benzoate is a bitterness threshold of 0.05 ppm for the benzoate and 0.01 ppm for the saccharinate, with 10 ppm described as unbearably bitter to most people. Those are human sensory thresholds, and humans detect denatonium at much lower concentrations than rodents do, so a threshold measured on people is not evidence of rodent deterrence. No rodent gnaw-test data for denatonium in a plastic compound appears in the sources behind this page, and no loading, let-down ratio or service life is published either. Denatonium benzoate is registered under REACH with 8 active full dossiers, and an EU title search on 22 September 2026 found no BPR approval decision for it as a PT19 active.

2. Capsaicinoids: Capsaicin and Its Derivatives#

Capsaicinoids are the pungent vanilloid amides of chilli peppers, led by capsaicin (CAS 404-86-4), which acts on the TRPV1 receptor so that a rodent that bites the article stops. Capsaicin carries EC number 206-969-8, the formula C18H27NO3 and a molar mass of 305.4 g/mol. The recorded plastics applications are rodent-repellent cable jackets, drip irrigation tubing and mulch film, and the capsaicinoid family also reaches the market as capsicum oleoresin, a mixture rather than a single substance.

Research on capsaicin in polymers has moved toward reactive and encapsulated derivatives rather than the free molecule, because free capsaicin irritates the people running the extruder and leaves the compound over time. Grafting it onto a phosphorus-containing backbone, or enclosing it in a cyclodextrin cage, keeps it in the matrix. On the EU side, Commission Implementing Decision (EU) 2022/1497 ruled that a product based on capsicum oleoresin (expeller pressed) and marketed as an animal repellent is a biocidal product, and that the oleoresin is a substance under REACH and the BPR. Capsaicin itself has no active REACH dossier (ECHA CHEM, 22 September 2026), and the same EU title search found no BPR approval decision for it as a PT19 active.

Combined Rodent-Repellent and Flame-Retardant Systems (Research Stage)#

Two published systems combine rodent deterrence with flame retardancy: a DOPO-capsaicin derivative at 4 wt% in EVA raised the char residue from 2.80 to 6.84 wt% and improved the limiting oxygen index (Wang and co-authors, Polymer Testing, 2021), and a cyclodextrin-encapsulated dihydrocapsaicin used with ammonium polyphosphate and dipentaerythritol in polypropylene reached an LOI of 30.9 % with non-lethal rat deterrence (Lan and co-authors, 2025). Both are laboratory systems reported in peer-reviewed journals rather than commercial grades, and the 4 wt% figure is the loading used in that study, not a recommended dosage.

These systems interest a cable compounder because they address two specifications with one ingredient, and the flame-retardant half of these systems is covered on flame retardants for plastics. The oxygen concentration at which a specimen just sustains combustion is measured as the limiting oxygen index (LOI), which is the value both studies report. The host polymer in the 2021 study, ethylene vinyl acetate, is the base of most halogen-free cable jackets and is covered on additives for EVA.

3. Pyrethroid Insecticides: Permethrin, Bifenthrin, Deltamethrin and Lambda-Cyhalothrin#

Pyrethroid insecticides are sodium-channel modulators incorporated into polyethylene film, sheet and filament, and four appear in the termite-barrier and netting literature: permethrin, bifenthrin, deltamethrin and lambda-cyhalothrin. Permethrin (CAS 52645-53-1, EC 258-067-9, C21H20Cl2O3, 391.3 g/mol) melts at 34 to 39 °C as the commercial isomer mixture and is the active in Termi-Film, the first termiticide-impregnated plastic sheet, and in the Olyset Net and Olyset Plus polyethylene nets. Bifenthrin (CAS 82657-04-3, EC 617-373-6, C23H22ClF3O2, 422.9 g/mol) is an off-white to pale tan waxy solid melting at 69 °C and is the active in the HomeGuard polyethylene barrier sheet.

Their EU status is the one part of this family carrying named instruments. Permethrin is approved for product-types 8 and 18 by Commission Implementing Regulation (EU) 1090/2014, with the approval expiry postponed by Decision (EU) 2026/336. Bifenthrin was included in Annex I of Directive 98/8/EC for product-type 8 by Directive 2011/10/EU, and it was not included for product-type 18 by Decision 2012/728/EU; its current PT8 approval and expiry status is not established in our sources and is not stated here. Bifenthrin also holds an EU plant-protection approval under Implementing Regulation (EU) 582/2012 and a harmonised CLP classification under index number 607-699-00-7. Deltamethrin and lambda-cyhalothrin are approved for product-type 18, with expiry postponements recorded in our dossier as (EU) 2025/2301 and (EU) 2025/2283.

Do Repellent Additives Work? What Is Published and What Is Only Claimed#

The evidence is uneven: termiticide-impregnated polyethylene barriers have a published field record, the two capsaicin flame-retardant composites report measured laboratory values, and for bitterants in plastics we found no published gnaw-test data at all. Every masterbatch page holding the commercial search results for anti-rodent masterbatch asserts durable rodent protection, and not one of them names an active substance, a loading, a test method or a duration. The table below separates the claim a buyer meets in the market from the measurement that exists behind it.

The piece missing behind every row is a common yardstick. No ISO, ASTM or EN standard for the rodent-gnaw resistance or repellency of plastics appears in the sources behind this page, so two vendor claims cannot be compared on the same basis even when both are made in good faith. The insecticidal side is better served, because the termite-barrier and net trials report durations and percentages, which is why the only quantified efficacy statements on this page belong to pyrethroids. Corrections and additional published data are welcome through the methodology page linked under the byline.

How Much Repellent Additive Does a Compound Need?#

No dosage range for anti-rodent or anti-termite additives in plastics is published in the sources behind this page, and any supplier figure should therefore be read as a formulation of that supplier rather than an industry norm. Our substance record for denatonium benzoate carries the entry "no data" under polymers and dosage, and no loading in plastics is recorded for permethrin or bifenthrin. No repellent row exists in our formulation dosage tables either.

Two reference points do exist, and the scope of each one stops it being a recommendation. The first is a composition band of 0.001 to 1 wt% for biocides in finished plastic products, tabulated by Chea and co-authors in 2025 from the Hahladakis review of 2018; that band describes what has been measured across the biocide category in products, not what a repellent compound requires. The second is the 4 wt% DOPO-capsaicin loading in the 2021 EVA study, a research formulation built to deliver flame retardancy as well as deterrence. Published levels for the families that do have them are collected on additive dosage levels in plastics. The practical consequence for a buyer is procedural rather than numerical: ask the supplier which active is in the masterbatch, at what concentration, and at what let-down ratio, then ask for gnaw-test or field data in writing with the test conditions and duration attached.

Which Polymers and Articles Carry Repellent Additives?#

Repellent and insecticidal additives appear in four article types: cable and conduit jackets, buried drip irrigation tubing and mulch film, under-slab termite barrier sheets, and insecticide-incorporated netting. Every article in this family except the PVC jackets is polyethylene, so the rest of the package is on additives for polyethylene. Drip tubing and mulch film carry their own package of light stabilizers and antioxidants; see additives for agricultural film.

Wire, Cable and Conduit Compounds#

Cable and conduit jackets are the main home of anti-rodent additives, and they are also the most crowded formulations on this site: a halogen-free jacket already carries 160 to 185 phr of mineral flame retardant, about 60 wt% of the compound, so a repellent has to fit into what is left. That constraint is the reason the combined repellent and flame-retardant research described above exists at all. The full jacket formulation is on additives for wire and cable compounds.

The mineral loading that fills the jacket first is on flame retardants for wire and cable, and it sets both the space and the processing window. Aluminium trihydroxide begins to dehydrate near 200 °C, which caps the melt temperature of a halogen-free compound and therefore caps the thermal stability an added repellent has to survive.

The PVC route is no emptier. A PVC jacket already carries heat stabilizers, plasticizers, lubricants and fillers, and the plasticizer fraction in particular is the phase an organic additive partitions into and migrates with; see additives for PVC. PVC cable insulation also has to hold a minimum limiting oxygen index of 26 vol%, so any additive that dilutes the flame performance has to be compensated elsewhere in the recipe.

Under-Slab Termite Barrier Films and Sheets#

A termiticide-impregnated barrier is a polyethylene sheet or film carrying a pyrethroid, laid under a slab or at its edge, and the product class starts with Termi-Film, the first such sheet. The products recorded in the 2022 review by Oi and co-authors are Termi-Film with permethrin, HomeGuard with bifenthrin, Trithor with deltamethrin, Impasse with lambda-cyhalothrin, and Kordon Blanket with deltamethrin.

Impasse was installed from 1999 and remained effective for more than 5 to 6 years in field tests before it was discontinued, and none of the impregnated barriers failed in the US tests reported by Wagner in that review. A separate class of physical, non-chemical barriers exists alongside the impregnated ones, and the US Environmental Protection Agency may treat those as devices rather than as pesticide products, because they carry no active substance at all. The other construction uses of additives are on additives for building and construction.

Insecticide-Incorporated Polyethylene Nets (LLINs)#

The largest-volume use of an insecticide incorporated into a polymer is not an industrial one: long-lasting insecticidal nets carry permethrin or another pyrethroid inside polyethylene filament. Olyset Net and Olyset Plus are polyethylene nets, while other long-lasting insecticidal nets use polyester filament. Dual-active nets, combining a pyrethroid with chlorfenapyr, pyriproxyfen or piperonyl butoxide, answer mosquito resistance.

The public-health performance of nets is outside this reference, which covers only the additive-in-polymer aspect of the product. One trial figure matters to anyone formulating an insecticidal polymer for long service, because it measures depletion and resistance together: Olyset Plus efficacy against resistant mosquitoes fell from 73 % at 6 months to 40 % at 24 months in the Mozambique New Nets Project reported in 2026. A pyrethroid held in a polyolefin matrix has to reach the surface to act, and that supply is finite.

How Are Repellent and Insecticidal Additives Regulated?#

Repellent and insecticidal additives are regulated as biocidal actives rather than as ordinary plastic additives, which means the decisive question is not a migration limit but whether the active is approved for the product-type that matches the claim. None of the four actives in this family has an entry in EU Regulation 10/2011, in the FDA food-contact regulations, on the California Proposition 65 list, in the POPs Regulation or in the TSCA records behind this page, and the absence of an entry is not a statement that a use is permitted. Every instrument that touches plastic additives is summarised in plastic additive regulations.

"No entry found" means our sources record no listing; it is not a statement that a use is permitted.

EU: Product-Types PT19, PT18 and PT8, and the Treated-Article Rules#

In the EU a rodent-repellent plastic article is a treated article: Article 3(1)(l) of Regulation (EU) No 528/2012 defines it as any substance, mixture or article that has been treated with or intentionally incorporates one or more biocidal products. Four duties follow from that classification, and they are listed below.

• Place the article on the market only where every active substance in the incorporated biocidal product is approved for the relevant product-type and use, and the approval conditions are met (Article 58(2))
• Label the article with a statement that it incorporates biocidal products, the substantiated biocidal property, the names of all active substances, the "(nano)" suffix for any nanomaterial, and the instructions and precautions for use (Article 58(3))
• Supply a consumer who asks for information on the biocidal treatment free of charge within 45 days (Article 58(5))
• Meet the transitional rule of Article 94, under which articles on the market on 1 September 2013 required an active-substance application by 1 September 2016

Article 58(2) is where this family becomes uncomfortable. A title search of EU instruments on 22 September 2026 found no BPR approval decision for denatonium benzoate or capsaicin as PT19 actives. Anyone placing a rodent-repellent compound on the EU market should confirm the status of the specific active with the supplier and, where needed, with a regulatory adviser. Registration under REACH is a separate question and does not answer the biocidal one: denatonium benzoate holds 8 active full REACH dossiers and still has no recorded PT19 decision, and what a registration does and does not mean is explained on REACH and plastic additives.

US: FIFRA Registration and the Treated-Article Exemption#

In the United States the decisive rule is 40 CFR 152.25(a), which exempts an article treated with or containing a pesticide to protect the article itself, provided the pesticide is registered for that use. The exemption turns on what the treated article is claimed to protect. A statement that the additive protects the cable jacket from being gnawed points at the exemption, because the object of protection is the article. A statement that the cable repels rodents from the room, the roof void or the vehicle around it describes pest control of a space, which is a pesticidal claim about something other than the article and takes the product outside the exemption.

That reading of the text, rather than legal advice, is what a formulator can act on at the specification stage: settle the claim first, then check that the active carries a US registration covering it. The same logic explains why the EPA may treat a purely physical, non-chemical termite barrier as a device, since no pesticide is present to register.

How Do You Select an Anti-Rodent or Anti-Termite Additive? 6 Steps#

Select an anti-rodent or anti-termite additive in 6 steps: decide between deterring and killing, identify the active, check its product-type approval, demand the efficacy evidence, check compatibility and processing, then agree the dose in writing. The steps run in that order because each one can stop the project, and the regulatory questions cost less to answer than a failed trial.

1. Decide whether the article must deter or kill, because that decision sets the product-type and with it the whole approval route.
2. Ask the supplier which active substance is in the masterbatch, with its CAS number, and treat a refusal as an answer in itself.
3. Check that active's approval status for the matching product-type in every market you sell into, remembering that bifenthrin is not included for PT18 and that no PT19 decision is recorded for either deterrent active.
4. Ask for the evidence: gnaw-test or field data, with the species, the conditions, the specimen and the duration stated.
5. Check the additive against the rest of the package and against the processing temperature of the compound, since a halogen-free jacket or a PVC recipe leaves little room and little thermal headroom.
6. Fix the dose with the supplier in writing, since no published norm exists, and confirm it on your own compound before production.

The general framework behind these steps is on how to select plastic additives.

Who Makes Anti-Rodent and Anti-Termite Masterbatch?#

Two suppliers are named in our sources: Aversion Technologies, which sells anti-rodent, anti-termite and combined masterbatches based on capsaicins and bitterants, and C-Tech Corporation, whose RodRepel, TermiRepel and CombiRepel lines do not disclose their active substances. No market size for repellent additives exists in the sources behind this reference, and this page does not repeat one. Other masterbatch producers appear on the commercial search results, and they are not listed here until their actives, loadings and test evidence can be verified. Company profiles across all families are in the directory of plastic additive manufacturers and suppliers.

Suppliers are listed because our sources name them. Send corrections or additions through the methodology page. The six questions in the selection section above work as an RFQ text for any producer on this list.

Complete List of Repellent Substances (4 Pages)#

The repellent family has 4 substance pages: denatonium benzoate, capsaicin, permethrin and bifenthrin, each with its CAS number, mode of action and regulatory record, in the type order used throughout this page.

All 435 substance records, with CAS numbers, functions, dosage where it is published and regulatory status, are in the plastic additives database.

Are Rodent-Repellent and Termiticide Additives Safe?#

The two deterrents and the two insecticides sit at different ends of the hazard scale: denatonium benzoate is classified for acute oral and inhalation toxicity and eye damage, while bifenthrin carries fatal-if-swallowed, suspected-carcinogen and organ-damage statements alongside very high aquatic toxicity. The distinction matters most to the people who compound and extrude the material, since the concentration in a masterbatch is far higher than in a finished article. The site-wide list of substances of concern is on toxic plastic additives.

What the Hazard Classifications Say#

Bifenthrin has a harmonised CLP classification under index number 607-699-00-7, and its hazard statements matter most to the people who handle the masterbatch, not to the end user of the finished cable. Bifenthrin carries H300, H317, H331, H351, H372, H400 and H410. Permethrin carries H302, H317, H332, H400 and H410. Denatonium benzoate carries H302, H332, H318 in 33 % of notifications, and H412. Both pyrethroids are therefore very toxic to aquatic life with long-lasting effects, and bifenthrin adds a suspected-carcinogen statement and a repeated-exposure organ-damage statement that neither deterrent has. How to read the statements is on safety data sheets and GHS labels.

What Happens to a Treated Plastic in Recycling and in the Environment#

A repellent additive is intentionally added and not chemically bound, so it travels with the polymer when a cable jacket or an agricultural film is recycled, and no study specific to repellent additives in recyclate appears in our sources. The H410 classification of permethrin and bifenthrin attaches to articles that spend their service life buried in soil or spread across a field, so the recycling question is not academic. No migration rate, leaching rate or recyclate concentration is published for these actives in plastics, and none is stated here. What additives in general do to recyclability is on design for recycling.

Additive or Hardware: How Cables Are Actually Protected From Rodents#

In practice the rodent problem on a cable is solved in two different industries: compounders add a repellent to the jacket, and cable makers add braided sleeving, tape armour or a harder jacket material. The hardware route holds the commercial search results for rodent-proof cable, the additive route holds the results for anti-rodent masterbatch, and the two rarely appear on the same page. No source in our records compares the cost or the field performance of the two approaches directly.

What Wire Can Rats Not Chew Through?#

No plastic jacket is rodent-proof on its own: the mechanical route uses metal armour or braided sleeving, the additive route uses a bitterant or a capsaicinoid, and no comparative test of the two appears in our sources. Steel tape armour and metal-containing sleeving resist the incisor mechanically, a different failure mode from deterring the bite, and a jacket compound does not deliver that resistance through chemistry alone.

Is a Plastics Repellent Additive the Same as a Rodent Repellent Spray?#

No: a repellent additive is compounded into the plastic and acts only on an animal that bites the article, while a repellent spray treats a room, a vehicle or a garden and is outside the scope of this reference. The additive is fixed for the life of the article at the compounding stage, whereas a spray is reapplied and is regulated as a pest-control product in its own right.