A reproductive toxicant or reprotoxicant will impair the ability to get children or cause irreversible harm to the offspring itself. Alterations include miscarriages, damage to unborn children’s development, alteration of breastfeeding capability, or negative inherited developmental effects. Legislation differentiates substances that are toxic for fertility and substances that damage development: Toxic for fertility are substances and compounds that may alter sexual behaviour reducing libido, causing erectile dysfunction and altering menstrual cycles. They can also damage ova and affect the quality of sperm or cause disorders in human reproductive organs. Developmental toxicity is associated with substances and compounds that can cause fatal damage to the unborn child, developmental disorders, innate disorders and childhood and adult health diseases due to prenatal exposure. Toxic substances on or via lactation can affect both mothers’ milk and breastfeeding children. They may also affect female workers’ by impairing their capability to breastfeed, reducing their milk production (endocrine disruptors) or passing on toxins to the babies. They are classified as substances of high concern in order to warn breastfeeding mothers about this specific hazard.

A) Substances which cause adverse effects on

sexual function and fertility

; According to DSD:

According to CLP:

B) Substances which cause adverse effects on

development of the offspring:

According to DSD:

According to CLP:

C) Substances which cause adverse effects on or via

lactation

: According to DSD:

According to CLP:

Given the serious effects of exposure to these agents they are classified as highly hazardous chemicals and risks from exposure must be avoided. Their elimination or substitution are priority actions and only in those cases where these actions are not technically feasible, workers’ exposure must be reduced through other measures (individual and collective protection) following the principles of preventive action according to

Directive 89/391/EEC

on the introduction of measures to encourage improvements in the safety and health of workers at work.

In view of the possibility of exposure of pregnant or breastfeeding women’s employers must:

1. Implement the necessary measures to avoid exposure by adapting the workplaces of affected workers.
2. Transfer the affected workers to work stations compatible with their condition whenever modification of workplaces is not possible.
3. Suspend the affected workers’ from their jobs during pregnancy or breastfeeding periods whenever transfer to other work stations is not possible. This option includes subsidizing affected workers (subsidized job suspension)

Hazard categories for reproductive toxicants

CATEGORY 1 Known or presumed human reproductive toxicant. Substances are classified in Category 1 for reproductive toxicity when they are known to have produced an adverse effect on sexual function and fertility, or on development in humans or when there is evidence from animal studies, possibly supplemented with other information, to provide a strong presumption that the substance has the capacity to interfere with reproduction in humans. The classification of a substance is further distinguished on the basis of whether the evidence for classification is primarily from human data (Category 1A) or from animal data (Category 1B). Category 1A Known human reproductive toxicant. The classification of a substance in Category 1A is largely based on evidence from humans.

Suspected human reproductive toxicant Substances are classified in Category 2 for reproductive toxicity when there is some evidence from humans or experimental animals, possibly supplemented with other information, of an adverse effect on sexual function and fertility, or on development, and where the evidence is not sufficiently convincing to place the substance in Category 1. If deficiencies in the study make the quality of evidence less convincing, Category 2 could be the more appropriate classification.

Hazard category for lactation effects

Effects on or via lactation are allocated to a separate single category. It is recognised that for many substances there is no information on the potential to cause adverse effects on the offspring via lactation. However, substances which are absorbed by women and have been shown to interfere with lactation, or which may be present (including metabolites) in breast milk in amounts sufficient to cause concern for the health of a breastfed child, shall be classified and labelled to indicate this property hazardous to breastfed babies. This classification can be assigned on the:

(a) human evidence indicating a hazard to babies during the lactation period; and/or (b) results of one or two generation studies in animals which provide clear evidence of adverse effect in the offspring due to transfer in the milk or adverse effect on the quality of the milk; and/or (c) absorption, metabolism, distribution and excretion studies that indicate the likelihood that the substance is present in potentially toxic levels in breast milk. H362: May cause harm to breast-fed children.

According to DSD reprotoxicant substances are divided into 3 categories:

Substances known to impair fertility in humans. There is sufficient evidence to establish a causal relationship between human exposure to the substance and impaired fertility.

Substances known to cause developmental toxicity in humans. There is sufficient evidence to establish a causal relationship between human exposure to the substance and subsequent developmental toxic effects in the progeny.

Substances which should be regarded as if they impair fertility in humans. There is sufficient evidence to provide a strong presumption that human exposure to the substance may result in impaired fertility on the basis of:

Substances which should be regarded as if they cause developmental toxicity to humans. There is sufficient evidence to provide a strong presumption that human exposure to the substance may result in developmental toxicity, generally on the basis of:

Substances which cause concern for human fertility Generally on the basis of:

Substances which cause concern for humans owing to possible developmental toxic effects Generally on the basis of:

Hazard category for adverse effects on or via lactancy

Substances which are classified as toxic to reproduction and which also cause concern due to their effects on lactation should in addition be labelled with R64.

For the purpose of classification, toxic effects on offspring resulting only from exposure via the breast milk, or toxic effects resulting from direct exposure of children will not be regarded as "Toxic to reproduction`, unless such effects result in impaired development of the offspring.

Substances which are not classified as toxic to reproduction but which cause concern due to toxicity when transferred to the baby during the period of lactation should be labelled with R64.

This R-phrase may also be appropriate for substances which affect the quantity or quality of the milk.

R64 would normally be assigned on the basis of : (a) toxicokinetic studies that would indicate the likelihood that the substance would be present in potentially toxic levels in breast milk; and/or (b) on the basis of results of one or two generation studies in animals which indicate the presence of adverse effects on the offspring due to transfer in the milk; and/or (c) on the basis of evidence in humans indicating a risk to babies during the lactation period.

The sources consulted for the preparation of this list are:

SourcePublication date

Regulation 1272/2008 (CLP)

Annexes I, VI and VIIJanuary 2011 Directive 67/548/EEC (DSD)Annexes I and IVJune 2011Directive 89/391/EECDirective 89/391/EECNovember 2005

Last update July 2012