Moth and vector proofing with permethrin under the European Regulation
Heiko Wünsche from TANATEX Chemicals explains all aspects of moth and vector proofing with permethrin under the European Biocidal Products Regulation
Permethrin based products have been used for many decades for the moth proofing of wool. Permethrin is also widely used in vector proofing. We give an overview of changes due to the introduction of the European Biocidal Products Regulation (BPR).
Permethrin
Permethrin (CAS 52645-53-1) is a substance from the group of synthetically produced pyrethroids, derived from the natural insecticide pyrethrum. Because of its toxicological properties permethrin is ideally suited for insect proofing: it has only a relatively low toxicity for warm-blooded creatures, the LD50 – determined in rats after oral administration – is higher than 4000 mg/kg bodyweight, for cold-blooded creatures, including insects, it is however much more toxic. Warm-blooded creatures (except for cats!) have an enzyme that hydrolyses permethrin relatively quickly after absorption and so renders it harmless.
This enzymatic breakdown is not available to insects. They absorb permethrin via the body surface and it spreads throughout their body. This leads to the sodium channels of the nerve cells not closing and the nerves then transmit signals under “sustained fire”. After a short exposure time this leads to coordination disorders followed by paralysis and finally death. Tests are carried out to determine the so-called ‘Knock-Down-Effect’. This enables a pronouncement to be made on the efficacy of the treatment.
Vector proofing
The insect stings an infected person and absorbs the pathogen through the blood. On the next ‘sting’ these pathogens are transmitted in the same way to other people (or animals). The insect is the vector for the pathogen. Vector proofing is therefore nothing other than insect proofing. It should prevent the wearer of the treated textiles being bothered by all sorts of blood-suckers. Just to give an idea of the effects: the figures for annual deaths, caused by diseases transmitted by insects, vary considerably according to the source. This is due mainly to the fact that it is impossible to obtain reliable figures from all over the world. Cautious estimates range from around 725,000 deaths worldwide, attributed to tropical diseases such as malaria, yellow fever, dengue fever, West Nile Fever and many others. The biggest problem continues to be malaria. According to figures from WHO, in 2015 214 million people were infected with malaria, 438,000 died from it. The figures have in fact been falling for many years, but are still far too high. Almost 80% of deaths are children aged under 5!
In recent times official reports on the spread of the Zika virus and its suspected effect on unborn children, has increased public awareness of the “mosquito” problem. The subject of global warming and the related further spread of certain insects play their part in the discussion. However, one does not have to go so far – to tropical regions. Here in our European climate problems due to tick bites and the diseases they transmit (Lyme disease, FSME and others) are increasing each year.
Protection from insect bites by clothing is one possibility for prevention, also popularly used in combination with insect repellents, applied directly to the skin. A closely woven, heavy fabric can of course also protect from bites just by its presence. But in the hot and humid climate of tropical countries it goes without saying why this is not very practicable. It is more pleasant for the clothing wearer to resort to light and airy articles which have vector proofing to help protect the wearer.
Vector proofing is available on all types of outdoor clothing. Socks, shirts and trousers such as hunting, walking and golf clothing can be treated, to give only a few examples. Uniforms for soldiers and security personnel are treated. Mattresses are also treated to protect the sleeper from mites and bedbugs.
Our animal friends should also be protected from insects. Dog and horse blankets can also be treated with insect protection. (As a reminder: never use permethrin-containing products for cat articles.)
Moth proofing
Clothes moths, carpet beetles and other family members of these species lay their eggs where animal hairs – thus wool – are found. Larvae emerge from the eggs and like to eat keratin-containing food. The result is immediately visible: holes in valuable carpet or expensive woollen clothing.
To avoid this permethrin has been used for many decades to protect wool. The concentrations are considerably lower than for vector proofing, as the larvae that eat the wool – and hence the permethrin – not only take it in over their body surface.
The details of quantities and the corresponding protection level are described for example by the “Woolmark Specification CP-4” of the “Woolmark Company”.
The details of quantities and the corresponding protection level are described for example by the “Woolmark Specification CP-4” of the “Woolmark Company”.
The EU Biocidal Products Regulation
“The Biocidal Products Regulation (BPR, Regulation (EU) No. 528/2012) regulates the placing on the market and use of biocidal products, which are used to protect humans, animals, materials or articles against harmful organisms, like pests or bacteria, by the action of the active substances contained in the biocidal product.” This is the original wording that can be found on the ECHA website.
The legal provisions of the regulation have been in force since 1 September 2013 and hence replace the Biocidal Products Directive applicable until then. Since 1 September 2015 within the EU only those biocidal products may now be used whose Active substance(s) are included in the so-called “Article 95 list”. TANATEX Chemicals B.V. is listed here as a “Product Supplier” for permethrin and the product type (PT) 18. Later more about the specific product types for permethrin.
In the last step then the biocidal products made from the active substances must be registered accordingly, so that they can (continue to) be marketed within the EU.
Biocidal products are used in numerous areas. The Biocidal Products Regulation divides these applications into 4 main groups with a total of 22 different product types. The product type describes the area of application. The biocidal product and its active ingredient(s) must be registered for the appropriate area of application, the product type. Under certain conditions a Europe-wide registration can be applied for or registration can be carried out in one Member State and “mutual recognition” requested in other member states. This means that if the product has been registered in one EU member state, then other EU states must recognise this registration.
Whether this involves a biocidal product that must be registered depends on the primary function. This can best be clarified from an example – with permethrin:
Example 1: A mosquito net treated with permethrin: this net has only one primary function: it should protect from mosquitos. It is therefore a biocidal product and must be registered as such.
Example 2:
Trousers treated with permethrin to protect against ticks. The primary function of trousers is and remains clothing. The insect proofing is an additional function. For this a biocidal product – a permethrin-containing formulation – is applied. In accordance with the Regulation this is defined as a “treated article”. This does not have to be registered as a biocidal product, but it must bear a label giving information on the biocidal function and the active substances used!
Of course the majority of textile manufacturing is carried out outside Europe. It is therefore interesting to look in more detail at how things stand with the registration obligations here. If treatment with a biocidal product is carried out within Europe, the biocidal product and its active substance(s) must be registered according to the product type. The “treated article” is given a label.
If the treatment with a biocidal product is carried out outside Europe, it must only be ensured that the active substance is authorised for the corresponding product type (see Article 95 list). To put it simply: where the active substance and the biocidal product come from, does not play any part here. The main thing is that the active substance is listed. Upon importation into the EU the article must be given the corresponding label. This then fulfils the requirements of the Biocidal Products Regulation!
Registration of product formulations
The vector proofing mentioned above falls under PT 18 “Insecticides, acaricides and products to control other arthropods”. TANATEX Chemicals B.V. will register the product BAYPROTECT® AM here. As higher permethrin concentrations are required in this area, this is a product formulation with around 40 % permethrin.
Moth proofing forms a special case. Originally for this application TANATEX Chemicals B.V. among others submitted a file for the active substance permethrin for PT 9. PT 9 stands for “Fibre, leather, rubber and polymerised materials preservatives”. This relates primarily to protection (from being eaten) of wool fibres. This does not include repelling moths. In April 2014 however the “Biocidal Products Committee (BPC)” of the ECHA decided in the area of moth proofing also to class permethrin under PT 18. The reasons: only products that protect textiles from microorganisms should be classified in PT 9.
There were individual reports in which it was maintained that the moth proofing of wool is therefore no longer possible. As TANATEX Chemicals B.V. we cannot uphold this. TANATEX has submitted a dossier for permethrin in PT 9; the ECHA (after discussion and consideration) has decided to continue with moth proofing for wool as PT 18. TANATEX will therefore register EULAN® SPA 01, a 10% permethrin formulation for conventional moth and beetle proofing. EULAN® has for many decades been the leading product for effective treatment of wool and wool mixtures.
If only for the sake of completeness it should also be mentioned that the active substance permethrin is still used as a wood protection treatment. This falls under PT 8.
Regulation in the USA
In a globalised world it is finally worth taking a brief look at the other side of the Atlantic. In the USA biocidal products are regulated in a similar way to that in Europe. There are clear parallels here, but also differences. The “Biocidal Products Regulation” in the USA is called “FIFRA” and this stands for Federal Insecticide, Fungicide, and Rodenticide Act. Just as the ECHA monitors the Biocidal Products Regulation here, in the USA the EPA (Environmental Protection Agency) monitors implementation.
In the USA the registration obligation focuses on what is “claimed” or “maintained”, the so-called “claims”. This can be most easily illustrated with an example:
If a textile is treated with permethrin and this is sold as “insect protection that prevents insect bites and the associated transmission of diseases” one has a so-called “health claim”.
The textile is hence the biocidal product and according to the FIFRA rules must be registered! If on the other hand we take the above-mentioned repellent treatment of a wool carpet: The permethrin treatment here only serves to protect wool. It is so to speak a preservative. It is not a “health claim”, so registration is not required
In any case the active substance used must have an EPA registration for the corresponding application. In the USA another type of permethrin is used with a different cis:trans ratio.
Relevant web links, date April 2016:
Regulation (EU) No. 528/2012: http://eur-lex.europa.eu/legal-content/DE/TXT/?uri=CELEX%3A32012R0528
ECHA Article 95 list: http://echa.europa.eu/de/information-on-chemicals/active-substance-suppliers
ECHA Biocidal Products Committee: http://echa.europa.eu/de/about-us/who-we-are/biocidal-products-committee
Opinions of the Biocidal Products Committee on the approval of active substances, here permethrin PT 18: http://echa.europa.eu/documents/10162/6d4b72f7-1f53-4787-bded-78746cb1ec5f
EPA: https://www.epa.gov/pesticides