Microorganisms are types of plant protection and public health substances that require certain specialist know-how. They are microorganisms (protozoan, fungus, bacterium, virus, or other microscopic self-replicating biotic entity) and any associated metabolites, to which the effects of pest control are attributed.

A MPCA and MPCP may contain:

• Viable and/or non-viable microorganisms.
• Secondary compounds (also may be called secondary metabolites) produced during cell proliferation (growth), which may or may not be toxicologically relevant.
• Material from the growth medium.

Any or all of these components can contribute to activity against the target.

Therefore:

• Registration is not just species- but strain-specific and correct taxonomy of the species and strain is vital.
• Production method is specific to the composition of each MPCA. Microorganisms are produced in vivo or in vitro by specific fermentation processes. The type of production method and the downstream processing method will alter the type of active substance and determine whether it contains cells, spent fermentation media and/or secondary compounds (metabolites).

Technical equivalence

Technical equivalence needs to be specific for a microorganism: the approved (reference) source needs to be demonstrated to be equivalent in one or more of the following cases:

• Change of location of manufacturing plant;
• Scale-up of fermentation vessel; or
• Change of manufacturing process, such as change of production equipment or propagation conditions (e.g. temperature or ingredients).

The aim is to ensure that the new source is equivalent to the approved source for the following parameters:

• Identity of the microorganism,
• Composition of material for production (e.g. inoculum, culture media),
• Content of the active microorganism (determined in relevant units),
• Content of relevant secondary compounds (metabolites),
• Content of microbial contaminants

An assessor can consider the new source as technically equivalent in Tier I and therefore no Tier II assessment is required when the strain or isolate is established as identical and the following criteria are fulfilled:

• Content of the active microorganism (determined in relevant units) is higher than or equal to (within the minimum-maximum range) the reference source; and
• Content of relevant secondary compounds (metabolites) is lower than/equal to the reference source; and
• Composition of material for production is the same; and
• Content of microbial contaminants is lower than/equal to the reference source.

However, higher levels can be accepted as long as the content of microbial contaminants in the product is within the agreed limits for microbial contamination for the MPCP.

If the above criteria are not fulfilled the MPCA can be considered under a TIER II assessment to determine if the changes in composition (chemical and/or microbiological) are with or without increased risk to human health and the environment. Additional information can be found in EU guidance.

Guidance

• Guidance document for the assessment of the equivalence of technical grade active ingredients for identical microbial strains or isolates approved under Regulation (EC) no 1107/2009. (2014). SANCO/12823/2012 –rev.4