Developmental toxins

WHO (2004) concluded that The mono- and disubstituted compounds that may leach from PVC water pipes for a short time after installation are primarily immunotoxins although they appear to be of low general toxicity, some are developmental toxins in rodents. The data available are insufficient to permit the proposal of guideline values for individual dialkyltins or the mono derivatives, although the concentrations observed in drinking-water are several orders of magnitude lower than the doses reported to cause developmental effects in rats and mice. ... 

Developmental toxins Reproductive toxins Endocrine disrupting substances... 

A general prescreen to select likely developmental toxins for subsequent whole-animal studies. 

Ethyl alcohol is a developmental toxin in humans. Excessive consumption is associated with fetal alcohol syndrome, which is characterized by joint, limb, and cardiac anomalies and behavioral and cognitive impairment. ... 

Toxicology. Hexachlorobenzene (HCB) causes porphyria, enlarged liver and thyroid, and neurological symptoms it is a developmental toxin, and in experimental animals it is carcinogenic. 

In limited studies hexachloroethane did not appear to be a selective reproductive or developmental toxin at doses below those causing maternal toxicity. ... 

Reproductive and developmental toxins are primarily a concern for livestock. 

Ethyl acetate has not been shown to be a human carcinogen or a reproductive or developmental toxin. 

Accutane is a potent rat and rabbit developmental toxin (teratogen). Testicular atrophy and evidence of lower spermatogenesis was noted in dogs given isotretinoin for 30 weeks at 20 or 60 mg kg day Fischer 344 rats dosed at 8 or 32 mg kg day for over 18 months had a dose-related raised incidence of pheochromocytoma, an adrenal gland tumor. The relevance in man is unknown since this animal develops spontaneous pheochromocytoma at a significant rate. 

Ethanolamines have not been found to be developmental toxins in standard or screening assays nor was diethanolamine found to be neurotoxic in a standard neurotoxicity test following subchronic inhalation exposure up to 400 mg m... 

Developmental studies have been performed via the dermal, oral, and inhalation routes of exposure in both rats and rabbits. Based on results of these studies, it appears NMP can sometimes cause developmental effects in the absence of maternal toxicity. Developmental toxicity is typically manifested by fe-totoxic effects (e.g., decrements in fetal body weight), although malformations have been observed above fetotoxic doses. NMP also appears to be a more potent developmental toxin via the inhalation route (lowest-observed-adverse-effect level or LOAEL equivalent to about 120 mg kg day than by either the oral (LOAEL about... 

There is sufficient evidence of carcinogenicity in animals. Repeated dietary administration has produced liver cell tumors in mice and bile duct and liver tumors in rats. Cirrhosis has also been observed in both rats and mice. Thioacetamide is a developmental toxin. 

It is a carcinogen and developmental toxin. Animal studies have shown that breathing in thorium may result in lung damage. Other studies in animals... 

EPA lists as a suspected developmental toxin. Also produced kidney and liver effects when given to rodents in high oral doses. 

Numerous single chemicals have been identified as known or suspected developmental toxins. 11,51 Some of these chemicals, including pesticides, heavy metals, pharmaceuticals, and industrial chemicals, are listed in Table 24.1. 

Some widely used fluorotensides have recently become the focus of environmental concerns. Compounds such as perfluorooctyl sulfonic acid and perfluoroocta-noic acid (PFOA) have environmental lifetimes on a nearly geological time-scale. Traces of these substances have been found to be present in the remotest locations on earth and the source of the contamination remains unclear. There is not yet much unambiguous evidence of negative physiological effects of these widely used fluorosurfactants, although perfluorooctyl carboxylates have attracted some critical attention as a potential developmental toxin in rats [37]. Some major producers have, therefore, already started to replace these tensides by more readily degradable alternative compounds. 

The building block for PC is BPA. This monomer exhibits toxic effects only at very high exposures and realistically, such high exposures are not possible under normal conditions indoors. BPA is not a carcinogen or a reproductive or developmental toxin. 

The principal study was well designed and well conducted, used a relevant exposure pathway, and examined the appropriate toxicological endpoints however, there was considerable variability in the blood ChE values of the exposed animals. The data base for GD lacks a toxicity study in a second species, chronic studies, as well as reproductive and developmental toxicity studies, including a multigenerational study. The unlikelihood that agent GD is a reproductive or developmental toxin reduces that significance of these data gaps. Overall confidence in the RfDe is low to medium. 

Catalog of Teratogenic Agents, 7th edition, Thomas H. Shepard, Johns Hopkins University Press, Baltimore, Maryland, 1992. This catalog is one of the best references available on the subject of reproductive and developmental toxins. 

Evaluate type of toxicity. Use the above sources of information to determine the type of toxicity associated with each chemical involved in the proposed experiment. Are any of the chemicals to be used acutely toxic or corrosive Are any of the chemicals to be used irritants or sensitizers Will any select carcinogens or possibly carcinogenic substances be encountered For many substances, it will be necessary to consult the listings of carcinogens in this chapter (see Tables 3.4 and 3.5) to identify chemical similarities to known carcinogens. Are any chemicals involved in the proposed experiment suspected to be reproductive or developmental toxins or neurotoxins ... 

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