Application of the threshold of toxicological concern (TTC) to the safety evaluation of cosmetic ingredients

The threshold of toxicological concern (TTC) has been used for the safety assessment of packaging migrants and flavouring agents that occur in food. The approach compares the estimated oral intake with a TTC value derived from chronic oral toxicity data for structurally-related compounds. Application of the TTC approach to cosmetic ingredients...

Assessment of intake from the diet

Exposure assessment is one of the key parts of the risk assessment process. Only intake of toxicologically significant amounts can lead to adverse health effects even for a relatively toxic substance. In the case of chemicals in foods this is based on three major aspects: (i) how to determine quantitatively the presence of a chemical in...

The no-effect level of sodium bromide in healthy volunteers

The long-term study in rodents for identifying carcinogens: Some controversies and suggestions for improvements

Despite increasing standardisation and international harmonisation of the long-term carcinogenicity study in rodents there are still areas of controversy such as high-dose selection, duration of the test period, combining or not combining the chronic toxicity and the carcinogenicity study, the use of historical control data, conditions for...

Nutritional factors in lung, colon, and prostate carcinogenesis in animal models

Dietary factors are now considered to be among the most important environmental risk determinations for cancer. In addition to epidemiological studies, experimental animal studies are an important tool to investigate dietary modulation in carcinogenesis. Results of recent experimental studies on the effect of some nutrients indicate that vitamin...

Adenocarcinomas of the prostate induced by n-nitroso-n-methylurea in rats pretreated with cyproterone acetate and testosterone

Prostatic adenocarcinomas were induced in 5 out of 20 Wistar rats upon a single administration of 50 mg/kg N-nitroso-N-methylurea (NMU). The rats were pretreated with a daily dose of 50 mg/kg cyproterone acetate for 3 weeks followed by 3 daily injections of 100 mg/kg testosterone. All tumours developed in the dorsolateral prostate and were...

Short-term tests in the framework of carcinogen risk assessment to man

Short-term tests designed to detect possible carcinogenicity have been extensively refined during the last years. Presently, many more or less simple and convenient systems are available to detect mutations, chromosome effects, DNA damage, and malignant transformation. Although their relevance to carcinogenicity is often reasonably good,...

Tissue damage and nutritional factors in experimental respiratory tract (co-)carcinogenesis

Cofactors involved in respiratory tract carcinogenesis were studied in Syrian golden hamster or in rats using benzo(a)pyrene as the carcinogenic agent. These factors included severe tissue tissue damage induced by electro-coagulation, glass fibers administered by intratracheal instillation, acetaldehyde as irritant vapor, food restriction, and...

Voeding en kanker

One-year time-sequence inhalation toxicity study of vinyl chloride in rats. II. Morphological changes in the respiratory tract, ceruminous glands, brain, kidneys, heart and spleen

Wistar rats were exposed to atmospheres containing 0 (control) or 5000 ppm vinyl chloride monomer (VCM), 7 h/day, 5 days/week, for a period of 52 weeks. After 4, 13, 26 and 52 weeks each time 10 rats/sex/group were killed and subjected to extensive examinations. The present paper describes the morphological changes observed in the respiratory...

Hexachlorobenzene toxicity in pigs

Spontaneous tumors of the brain in rats; a report of 3 cases

Three cases of spontaneous cerebral tumors are reported in Wistar rats, 2 oligodendrogliomas and 1 malignant ganglioglioma or astrocytoma (grade 4). © 1968, American College of Veterinary Pathologists.