Pesticide Registration Toolkit

The classification procedure in practice

Options to obtain a GHS classification

Two options can generally be followed for hazard classification of a pesticide product according to the GHS:

  1. The applicant is required to propose a classification and label of the product; the Registration Authority subsequently verifies the proposed classification, and if needed amends it.


  2. The Registration Authority itself classifies the product and requires the applicant to apply this on the label.

Which of these options is applicable in a country will depend on national pesticide legislation, and in particular the data requirements for submission of a registration application. Nevertheless, in both cases the Registration Authority can use different approaches to classify the product or verify a proposed classification.


i.    Use of existing classifications of the pesticide product as defined by other regulators.

Pesticide products may be classified according to the GHS by regulators in other countries or regions. If the Registration Authority considers certain other regulators as a reference, it may decide to accept the GHS classification by that other regulator. No additional evaluation is then needed by the Registration Authority.

This approach is relatively quick. However, a pesticide product is generally a formulation of the active ingredient and several co-formulants, each with their specific hazards. The pesticide product classified by the other regulator therefore should be identical or equivalent to the product to be classified by the Registration Authority.

Most databases of GHS classifications apply to active ingredients and not to formulated products. The Registration Authority may therefore require the applicant to provide copies of approved labels of the same product from reference countries which apply the GHS. Alternatively, it may be possible to find the GHS classification of a pesticide product by checking the Approved Labels section of the Information Sources module in the Toolkit.


ii.     Hybrid approach: Classification by the Registration Authority on the basis of existing classifications of the active ingredient and co-formulants.

While GHS classifications of specific pesticide products may be difficult to find (see i.), several national and regional regulators publish GHS hazard classifications of pesticide active ingredients and major co-formulants. These can be found in the Hazard Classifications section of the Information Sources module in the Toolkit.

The Registration Authority can decide to use such existing classifications defined by other regulators. There will be no need for the Registration Authority to evaluate most of the physical and (eco-)toxicological data of the active ingredient and relevant co-formulants. Instead, they can make use of the evaluations and the resulting classifications already conducted by reference regulators.
However, since only active ingredients and co-formulants may have been classified by the other regulator, the Registration Authority still needs to classify the formulated pesticide product. This generally requires taking into account the concentrations and classifications of the various individual constituents of the pesticide product.

This hybrid approach makes optimal use of existing classifications and as such reduces the work load for the Regulatory Authority. However, in some cases, hazard classifications of certain active ingredients or co-formulants may not have been published by other regulators. In such a case, approach iii. still needs to be followed.

iii.    Classification by the Registration Authority on the basis of physico-chemical and (eco-)toxicological data.

In this approach, the Registration Authority obtains the relevant physical and (eco-)toxicological data needed to classify the pesticide product and/or its constituents, either from the registration dossier submitted by the applicant or from reputable other sources. It then identifies the hazard categories for the various hazard classes, by comparing these data with the GHS hazard classification criteria.

This approach is relatively complex and time-consuming, since physical and (eco-)toxicological studies need to be evaluated, appropriate endpoints of those studies identified, and compared to the GHS classification criteria for each of the hazard classes. However, it is also the most precise GHS classification of a given pesticide product, based on the data that are available for the specific pesticide product under review.

These three approaches for GHS hazard classification are described in more detail in the Assessment Methods module.


Data requirements and testing guidelines

A registrar needs some basic data to carry out a control of a submitted label or to classify the pesticide product and its active substance. While data from internationally harmonized test methods are preferred, in practice, data from national methods may also be used where they are considered as equivalent.
Further information on data requirements for GHS classification is available in the Assessment Methods for physical hazards, health hazards and environmental hazards.

Criteria for classification

GHS is divided into four parts where Part 1 contains some introductory information, Part 2 the criteria for physical hazards, Part 3 the (human) health hazards and Part 4 the environmental hazards. These hazards are summarized in the tables below. Each specific hazard (e.g. flammability or acute toxicity) is described in a separate chapter under the Assessment Methods for classification, in the Toolkit.

Physical hazards

Most of the physical hazards in the GHS originate from the UN Recommendations on the Transport of Dangerous Goods in which methods and criteria are well developed and described. Generally, it is not possible to calculate classification of a mixture from the physical hazard classification of the ingredient substances which means that testing of the product itself is necessary.

Not all physical hazards are relevant for pesticides. Generally, if a pesticide fulfils the criteria of any of the physical hazards which are not marked as relevant in the table, it will not be authorized for use in the first place (e.g. a pesticide will never be explosive). 

Physical hazards in the GHS

Hazard class

Relevant for pesticides



Flammable gases


Aerosols and chemicals under pressure


Oxidizing gases


Gases under pressure


Flammable liquids


Flammable solids


Self-reactive chemicals


Pyrophoric liquids


Pyrophoric solids


Self-heating chemicals


Water reactive – emits flammable gases


Oxidizing liquids


Oxidizing solids


Organic peroxides


Corrosive to metals


Desensitized explosives



Health hazards

The GHS contains the following classification for ten health hazard classes. Each hazard class is further differentiated in hazard categories based on the severity of reaction or strength of available evidence, for instance human data versus animal test data. Classification of a mixture is derived using either a calculation method or by applying cut-off values/concentration limits.

Human health hazards in the GHS

Hazard class

Relevant for pesticides

Acute toxicity


Skin corrosion/irritation


Serious eye damage/eye irritation


Respiratory or skin sensitization


Germ cell mutagenicity




Reproductive toxicity


Specific target organ toxicity – Single exposure (STOT-SE)


Specific target organ toxicity – Repeated exposure (STOT-RE)


Aspiration hazard



Environmental hazards

The GHS currently contains only two environmental hazards. 

Environmental hazards in the GHS

Hazard class

Relevant for pesticides

Acute (short-term) hazard and chronic (long-term) hazard for the aquatic environment


Hazardous to the ozone layer


The methods that are used to classify physical, health and environmental hazards are described in more detail in the Assessment Methods module of the Toolkit.