Candidates for substitution: pesticides active substances

An active substance is a ‘candidate for substitution’ if it has certain properties. These properties usually indicate a substance is more hazardous, so a candidate for substitution can only be approved for a maximum of 7 years before it needs to renewed.

HSE identifies candidates for substitution as part of the active substance approval process.

Candidates for substitution are identified in the GB approvals register^[1].

You can still use a candidate for substitution in a plant protection product (PPP), but you might be asked to provide a comparative assessment.

Comparative assessment

Comparative assessment is how HSE compares the risks and benefits of a PPP containing an active substance that is a candidate for substitution. The assessment compares your product against other control or prevention methods for the same use.

Several factors decide if a comparative assessment is needed including:

• that the PPP contains a candidate for substitution
• the PPP is for use on a major crop^[2]
• the PPP presents a new risk
• whether there is an alternative option available
• that substitution does not cause adverse consequences on crop protection - this includes authorised minor uses
• that the PPP is only available for professional use
• there are enough modes of action available to stop resistance build up

Where you need to get experience of using a product in practice, you can ask for an authorisation without a comparative assessment. This type of authorisation is only available once and lasts for a maximum of 5 years.

If the comparative assessment shows there are suitable alternatives available, it may result in substitution.

Comparative assessment and substitution^[3]

Substitution

Substitution of a PPP can only happen when it contains a candidate for substitution.

After a comparative assessment, HSE may refuse, restrict or withdraw your application in favour of another control or prevention method.

HSE may refuse your application if:

• the alternative control or prevention method shows significantly lower risk
• substitution does not cause adverse consequences on crop protection

GB comparative assessment and substitution, Article 50, retained Reg (EC) 1107/2009 (legislation.gov.uk website)^[4].

Northern Ireland

Active substances that are candidates for substitution in Northern Ireland (NI) may differ to those in Great Britain due to the Protocol on Ireland/Northern Ireland in the EU withdrawal.

You can find the NI list of candidates for substitution in the EU active substances database (Europa website)^[5].

EU Guidance on comparative assessment and substitution of Plant Protection Products (Europa website). (PDF) ^[6]