Pesticides: vertebrate testing (toxicology)

It is a requirement of regulation 1107/2009 that in vivo tests in vertebrate animals tests must not be conducted where validated alternative methods are available and can reliably be used. This page provides guidance on some of the conditions, requirements and considerations relating to vertebrate testing and the use of alternative methods in the area of toxicology, for the approval/authorisation of pesticide active substances and formulated plant protection products (PPPs).

Background

Regulation 1107/2009 came into force on 14 June 2011 and lays down a number of requirements aimed at avoiding unnecessary testing on vertebrate animals, where alternative methods are available, avoiding duplicate testing and prescribing sharing of tests and studies involving vertebrate animals.

Article 62 of regulation 1107/2009 requires that:

testing on vertebrate animals for the purposes of this Regulation shall be undertaken only where no other methods are available.

In practice the regulation prescribes that no new studies shall be conducted in vertebrate animals where validated alternative methods are available. HSE interprets validated alternative methods as in vitro methods which allow the prediction of in vivo endpoints and for which OECD test guidelines have been adopted. When new OECD test guidelines for alternative in vitro methods fully or partially replacing an in vivo test are adopted, any new studies should be conducted using these alternative methods. This is particularly relevant to the assessment of skin and eye irritation/corrosion.

In accordance with the regulation, dossiers submitted for the approval of active substances and authorisation of PPPs should include 'for each test or study involving vertebrate animals, a justification of the steps taken to avoid animal testing and duplication of tests and studies on vertebrate animals' (article 8(1)(d) and article 33(3)(c) respectively).

In vivo tests conducted either before the implementation date of regulation 1107/2009 or before alternative OECD test guidelines were adopted may be submitted, subject to the requirements of article 62 regarding data sharing and duplicate testing.

In the UK, The Plant Protection Products Regulations 2011 ( are the enforcing regulations for Regulation (EC) No 1107/2009, and provide under regulation 15(1) that:

1) a person must not undertake tests on vertebrate animals in contravention of the first sentence of Article 62(1), or cause or permit another person to do so

And under regulation 23 that:

2) a person who contravenes or fails to comply with – any paragraph of regulations 9 to 13, 15 to 19, or 22;…… is guilty of an offence

The fact that a test may also be carried out for the purposes of an application or authorisation in another non-UK regulatory body/authority which may have less stringent rules regarding testing on vertebrate animals does not invalidate the provisions of article 62 in the UK.

HSE will contact applicants where there is a concern that a breach of article 62 (1) of the regulation has occurred.

Acceptable alternative methods

The regulation prescribes that no new studies shall be conducted in vertebrate animals where validated alternative methods are available. HSE interprets validated alternative methods as methods that allow the prediction of in vivo endpoints, for in vitro studies these are acceptable where OECD test guidelines have been adopted. Examples of validated and acceptable alternative methods are the adopted OECD test methods for in vitro skin and eye irritation. In addition, for the toxicological assessment of PPPs, the calculation method of Regulation 1272/2008 (CLP) may be used as an alternative method to fulfil the data requirements for acute toxicity, skin and eye irritation and skin sensitisation. Further information on these alternative methods is available in the following sections.

Calculation method

The calculation method of Regulation 1272/2008 (CLP) may be used as an alternative method for fulfilling the toxicological data requirements for PPPs as described in section 7.1 of Regulation 284/2013 (acute toxicity, skin irritation, eye irritation and skin sensitisation) and for the human health hazard classification of the formulation for these properties and other potential hazards.

As an acceptable alternative method to whole formulation in vivo testing, consideration of the application of the calculation method should always be made in advance of any formulation testing in vertebrate animals for the previously stated toxicological properties. HSE will not accept information from formulation studies conducted in vertebrate animals after the entry into force of Regulation 1107/2009 (June 2011) where the calculation method (or other validated alternative method) could have reliably been used.

For the classification of formulated PPPs for all other human health hazards (for example, specific target organ toxicity, carcinogenicity, mutagenicity, reproductive toxicity) the calculation method of CLP must always be used.

The calculation method allows for mixtures of chemicals (such as PPPs) to be classified for human health hazards in accordance with CLP, without conducting any specific toxicology testing. The calculation method utilises information on the toxicity and classification of the components of a mixture to conclude on the overall toxicological hazard and classification of the mixture. For the assessment of PPPs this information is predominantly taken from valid Safety Data Sheets (SDS), but information from other reliable sources may be used where appropriate.

The guidance document on the application of CLP contains information on the application of the calculation method; this is available via the ECHA CLP Guidance page.

For skin sensitisation, HSE requires, in general, reliable information (eg experimental data) on the skin sensitisation potential of all components in the mixture for a negative prediction using the calculation method to be acceptable.

In vitro studies

Skin irritation/corrosion studies

To fulfil the data requirement for skin irritation for pesticide active substances and plant protection products, testing should be conducted as described by Regulations 283/2013 and 284/2013 respectively. Sections 5.2.4 and 7.1.4 of Regulations 283/2013 and 284/2013 respectively require the application of a tiered testing strategy; this should be implemented in accordance with the recommendations of the OECD guidance on an integrated approach on testing and assessment (IATA) for skin corrosion and irritation.

A validated in vitro test for skin irritation potential (OECD Test Guideline 439) has been available since 2010. A number of validated in vitro tests for skin corrosion potential have been available since 2004. These tests should be used alongside all other available information (including information from dermal toxicity studies, physical/chemical properties, non-testing methods) in a weight of evidence approach, ahead of any in vivo testing. In vivo testing for skin irritation/corrosion (eg OECD Test Guideline 404) should only be performed as a last resort and where no other options remain. Should testing in vivo be deemed necessary, a full justification must be provided that explains the need to perform the test, with reference to the IATA.

Eye irritation/corrosion studies

To fulfil the data requirement for eye irritation for pesticide active substances and plant protection products, testing should be conducted as described by regulations 283/2013 and 284/2013 respectively. Sections 5.2.5 and 7.1.5 of regulations 283/2013 and 284/2013 require the application of a tiered testing strategy; this should be implemented in accordance with the recommendations of the OECD guidance on an integrated approach on testing and assessment (IATA) for serious eye damage and eye irritation.

Validated in vitro/ex vivo eye irritation tests (for example, OECD Test Guidelines 437 and 438) have been available since 2009. The available in vitro tests are able to identify substances classified for serious eye damage (category 1) and those not classified for serious eye damage/eye irritation, in accordance with regulation 1272/2008. These tests should be used alongside all other available information (including information from physical/chemical properties, non-testing methods) in a weight of evidence approach, ahead of any in vivo testing.
In vivo testing for the potential to cause serious eye damage/eye irritation (eg OECD Test Guideline 405) should only be conducted as a last resort, where it is not possible to conclude on serious eye damage/eye irritation hazard categorisation and in accordance with the IATA. Should testing in vivo be deemed necessary, a full justification must be provided that explains the need to perform the test, with reference to the IATA.

Date of application

The requirement to use alternative methods to in vivo testing applies from the date of implementation of regulation 1107/2009. The implementation date of the regulation was 14 June 2011. In practice, HSE will not accept studies in vertebrate animals conducted after this date where an alternative method could have reliably been used.

What this means for applicants

HSE will contact applicants where there is a concern that a breach of article 62 (1) of the regulation has occurred. This applies to vertebrate studies commissioned after 14 June 2011.

If any in vivo studies are submitted to HSE as part of an application for authorisation of a pesticide product or active substance, and the date of the study indicates it was commissioned after 14 June 2011 and an acceptable alternative method (for example, an adopted OECD Test Guideline for an in vitro alternative, or the calculation method) could reliably have been used, then the study will not be accepted. HSE will also consider whether to conduct an investigation in relation to the potential breach of article 62(1) of the regulation.

The applicant may resubmit the application using either the calculation method or acceptable in vitro studies.

Adverse data

Compliance with article 62 (1) of the regulation does not obviate the applicant's obligation to submit adverse data. Under article 56 (1) of the regulation, an authorisation holder has an obligation to report all adverse data. Should a vertebrate study be available (for instance where it was conducted for another regulatory purpose or in another jurisdiction) that indicates a more adverse outcome (meaning a more severe hazard classification) than alternative methods, the in vivo studies must be submitted and will be considered by HSE as part of the hazard identification and classification of the chemical or mixture.