All biocidal products carry potential risks to people, non-target animals or the environment. Rodenticides can carry a higher risk than other biocidal products because their use, appearance and smell may make children, pets and other non-target animals more likely to be harmed.
You can find details of the:
- individual rodenticide products authorised for use in Great Britain (GB) and Northern Ireland (NI) on the UK List of Authorised Biocidal Products
- active substances used within rodenticide products authorised for use in GB and NI on the BPR active substance lists
Rodenticides can be grouped by their mode of action, meaning, the way they work. The mode of action of a biocidal product usually depends on the active substance it contains. One of the most used rodenticide groups are the anticoagulant rodenticides, sometimes referred to as ‘anti-vitamin K rodenticides’ or ‘AVKs’.
Anticoagulant rodenticide active substance approvals
Under the Biocidal Products Regulations (BPR), the anticoagulant rodenticide active substances meet criteria in Article 5(1) that mean they would not normally be approved for use in biocidal products. They are toxic for reproduction and, in most cases, are persistent, bioaccumulative or toxic in the environment (PBT).
However, a derogation in Article 5(2) of the BPR allows higher risk active substances to be approved in certain circumstances.
The anticoagulant rodenticide active substances currently meet the criteria for this derogation as:
- they are essential to prevent a serious danger to human health, animal health and the environment
- not approving the active substances would have a disproportionate negative impact on society compared to the risk to human health, animal health or the environment arising from the use of the substances
As part of the most recent renewals of anticoagulant rodenticide active substances concluded in 2017, the European Commission carried out consultations to gather information on alternatives and whether the conditions for derogation were met. In discussion with member states, it was concluded that:
- non-chemical control or prevention methods could not be relied on to prevent the serious danger that pathogen-carrying rodents pose to human and animal health
- not approving anticoagulant rodenticide active substances could lead to insufficient rodent control and that would have significant negative impacts on human and animal health and the environment, as well as economic and social consequences – and that the risks arising from the use of anticoagulant rodenticide active substances can be mitigated
The derogation criteria must be reassessed at each renewal of the anticoagulant rodenticide active substance approvals.
Anticoagulant rodenticide biocidal product authorisations: Article 19(5)
Biocidal products are typically only authorised if they meet the conditions for authorisation indicated in Article 19(1) of the BPR. Amongst other criteria that must be met, this ensures authorised biocidal products have no unacceptable effects on the health of humans, animals or the environment.
However, a derogation provided by Article 19(5) of the BPR allows biocidal products to be authorised where those conditions are not fully met. This applies where it can be demonstrated that not authorising the products would result in disproportionate negative impacts for society compared to the risks to human health, animal health or the environment from using the products.
Anticoagulant rodenticides are authorised via this derogation as the risks from not using them outweigh the risks of their use. However, the derogation requires they be subject to appropriate risk mitigation measures to minimise the exposure of humans, animals and the environments to the products.
Comparative assessment
Article 10(1) of GB BPR states an active substance shall be considered a candidate for substitution if it meets at least one of the exclusion criteria listed in Article 5(1) but may be approved in accordance with Article 5(2).
If a biocidal product contains a candidate for substitution, a comparative assessment must be carried out (as described in Article 23 of GB BPR) before a decision is taken on the authorisation or renewal of the product.
The comparative assessment will determine, for each of the products’ uses, if:
a. other authorised biocidal products, non-chemical controls or prevention methods already exist that:
i. present a significantly lower overall risk for human health, animal health and the environment
ii. are sufficiently effective
iii. present no other significant economic or practical disadvantages
b. the chemical diversity of the active substances is adequate to minimise the occurrence of resistance in the target organism.
Where all of these criteria are demonstrated to be met, supply and use of the anticoagulant rodenticide products must be restricted or prohibited.
In 2017, as part of the most recent renewals of anticoagulant rodenticide products, the European Commission conducted an EU wide comparative assessment. It concluded that, in the absence of anticoagulant rodenticides:
- the chemical diversity of other active substances was not adequate to minimise the occurrence of resistance in rodents
- there were significant practical or economic disadvantages among products containing alternative active substances
- there was insufficient scientific evidence to demonstrate that the non-chemical alternatives identified, such as traps and glue boards, were sufficiently effective in controlling rodent infestations
Other rodenticide authorisations
Rodenticides containing non-anticoagulant active substances are also authorised in GB and NI under GB and EU BPR.
Although these rodenticides have different modes of action to the anticoagulant rodenticides, some of them also meet criteria under BPR that mean the active substances are considered candidates for exclusion and candidates for substitution.
Cholecalciferol, also known as vitamin D3, is an active substance used in bait products that can be used in a similar way as anticoagulant rodenticides, against rats and mice. It also meets criteria in Article 5(1), meaning it would not normally be approved for use in biocidal products and is considered a candidate for substitution. However, cholecalciferol also meets the derogation criteria in Article 5(2) meaning it can be approved for use in biocidal products, which are authorised via the Article 19(5) derogation.
Other rodenticides do not meet exclusion criteria and can be authorised for use as they meet the criteria in Article 19(1). However, they must still only be used by those with appropriate training and only in accordance with strict mitigation measures to reduce their risks. Examples of alternative active substances approved for use in rodenticide products include:
- alphachloralose
- phosphine gas released from aluminium phosphide
- carbon dioxide
- hydrogen cyanide