change penetration and distribution. The emphasis of any

testing is likely to be more focused on phytotoxicity in

these situations.

•

Changes in surfactant systems: These are widely regarded

as having potentially the greatest impact on effectiveness

in most situations. They may change the wetting, spread-

ing

and

sticking

properties

of

the

formulation.

Such

changes could include changing the contents of individual

existing surfactant(s), i.e. adding to them or replacing

them with chemically different surfactant(s). The empha-

sis on biological testing is likely to be more on effective-

ness.

Table 2 gives further details on the significance of the

change and the nature of any supporting evidence required.

Please also note that other criteria are relevant for more

specialized formulation types and certain situations of use

(see Appendix 1).

Test crops and key targets

Selection of the test crop for crop safety trials should be

based

on

the

most

sensitive

crop(s)

covered

by

the

authorized uses. This would be considered the more chal-

lenging and representative situation, particularly in labora-

tory or protected

studies where young plant foliage may

be more sensitive to damage. The use should be within the

authorized

uses

and

include

a

representative

range

of

growth stages. For effectiveness it is necessary to consider

whether the most sensitive crop is also an appropriate test

for the key targets. Key targets should be among the most

difficult to control where effectiveness is the key concern.

It may also be useful to consider crop morphology to

include, for example, waxy crops.

It may also be useful to consult, where available, the

EPPO

extrapolation

tables

for

further

guidance

on

key

major crop

–

pest combinations considered relevant for the

whole crop

–

pest grouping.

Table 1.

Biologically nonsignificant changes in chemical composition of the formulated product

Proposed change

Exchanging co-formulants for the same amount of chemically equivalent

*

co-formulants

Alternative source of same co-formulant

Adding (or changes to) a marker co-formulant (e.g. dye)

Changes in co-formulants added to preserve the formulation in the container or in the tank (e.g. preservatives, antifreeze and antifoaming agents)

Changes to the fertilizer component of granular herbicide fertilizer-based granules. The nature of the manufacturing process means that often several

different forms of nitrogen, phosphorus, potassium or other elements may be included. Variations in fertilizer base are considered unlikely to affect

product performance

In general, changes of less than

Æ

10% in the amount of any co-formulant applied

*

CAS or EINECS/ELINCS number of the co-formulants do not by themselves provide evidence of chemical equivalence (see main text for more

explanation).

Formulation details should include the expected concentration range of all the raw materials used in the production of the fertilizer base and the

minimum specification of the final formulated product. Details should include the N:P:K ratio, active substance content, particle size, density and

dust content.

Beyond the 10% threshold, supporting data may be required (see Part II for details). Some products contain two or more co-formulants with the

same function (e.g. wetters). Provided they are chemically similar, it may be acceptable to change the quantities of individual surfactants by more

than 10% provided the overall content is not changed by more than 10%. A case to justify the similarity of the co-formulants concerned should be

provided.

Table 2.

Biologically significant changes in chemical composition of the formulated product

*

Formulation component

Type of change and required supporting evidence

Solvent content not chemically equivalent

Where such changes in content are

>

10% (increase or decrease): functional equivalence in

effectiveness and selectivity shown on test crops in glasshouse/pot tests

Surfactant content not chemically equivalent

Where such changes in content are

>

10% (increase or decrease): functional equivalence in

effectiveness and selectivity shown on test crops in glasshouse/pot tests

pH adjuster

Changes of

>

10% (increase or decrease): functional equivalence in effectiveness and

selectivity shown on test crops in glasshouse/pot tests

*

Please see Table 1 for further explanation on determining comparability of co-formulant.

Calculating change in content is based on the individual content of the relevant co-formulant components, i.e. a change from 10 to 15 g/L is a 50%

increase (not a 5% increase). Where changes are being made simultaneously to more than one solvent or more than one surfactant, the cumulative

changes in content should be taken into account.

In the previous version of this Standard this was called ’glasshouse’,

but it has been changed to ’protected’ as it includes other conditions.

PP 1/307(2) Efficacy considerations

3

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2020 OEPP/EPPO,

Bulletin OEPP/EPPO Bulletin

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, 1–7