Germ cell mutagens, human

Studies are not needed if the substance is a known genotoxic carcinogen and/or a germ cell mutagen and appropriate risk management measures are implemented. Also, the studies are not needed if the substance has no evidence of toxicity, there is no systemic absorption (from toxicokinetic data) and there is no significant human exposure. 

The basic idea of the CLH process is the transfer of responsibility for classification and labeling from industrial companies to authorities on a European Community level. In case of active substances in biocidal or plant protection products, all intrinsic properties including physicochemical properties, human health hazards, and environmental hazards are subject to the harmonization. By contrast, in the case of chemicals which are used in other application fields only some specific hazard classes are considered in the CLH procedure. According to Article 36 of the CLP Regulation, these are respiratory sensitization, carcinogenicity, germ cell mutagenicity, and reproductive toxicity. Consequently, these provisions have... 

This hazard class is primarily concerned with chemicals that may cause mutations in the germ cells of humans that can be transmitted to the progeny. However, mutagenicity/genotoxicity tests in vitro and in mammalian somatic cells in vivo are also considered in classifying substances and mixtures within this hazard class. 

Positive results from tests showing mutagenic effects in the germ cells of humans, without demonstration of transmission to progeny for example, an increase in the frequency of aneuploidy in sperm cells of exposed people. 

BPL is a direct-acting alkylating agent and forms DNA adducts. It is mutagenic in a wide variety of in vitro and in vivo systems, both in somatic and germ cells. The lARC has determined that BPL is carcinogenic in experimental animals and that it is possibly carcinogenic to humans. ... 

How can data from diverse test systems best be used to identify possible chemical mutagens and to assess their potential damage to human germ cells ... 

There are other possibilities the material did not reach the germ cells the chemical was inactivated in the mouse body the DMA damage was almost completely repaired by a mouse repair system the cell stages treated were insensitive cell death eliminated the mutagenized cells. If humans respond in the same way as mice, it is arguable that human germ cells will be similarly unaffected. However, the human system may not be the same as that of the mouse, and... 

If transposons cause human mutation in significant numbers, this will necessitate some revision in mutagenicity testing. The mechanisms of transposition may be more akin to those of crossing-over. It is quite likely that many chemicals that induce base substitutions or chromosomal breaks may have little influence on transpo son-induced mutation, whereas other chemicals may affect transposons specifically. In this regard, it is interesting that some transposons act exclusively in germ cells, but not in somatic cells. 

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