Lack of in vivo mutagenicity of carbendazim in the liver and glandular stomach of MutaMice.

Background: Carbendazim (methyl 2-benzimidazolecarbamate, CASRN: 10605-21-7) exhibits spindle poisoning effects and is widely used as a fungicide. With respect to genotoxicity, carbendazim is deemed to be non-mutagenic in vitro, but it causes indicative DNA damage in vivo and chromosome aberrations in vitro and in vivo. In this study, we examined the mutagenicity of carbendazim in vivo.

In vivo mutagenicity assessment of orally treated tert-butyl hydroperoxide in the liver and glandular stomach of MutaMouse.

Background: tert-Butyl hydroperoxide (TBHP; CAS 75-91-2), a hydroperoxide, is mainly used as a polymerization initiator to produce polyethylene, polyvinyl chloride, and unsaturated polyester. It is a high-production chemical, widely used in industrial countries, including Japan. TBHP is also used as an additive for the manufacturing of food utensils, containers, and packaging (UCP).

Derivation of subacute guidance values for chemical contaminants of drinking water quality standard in Japan.

The concentration of chemicals in drinking water may transiently and accidently exceed the Drinking Water Quality Standard (DWQS). If the level of a contaminant is not expected to cause adverse effects for a limited period of exposure, immediate suspension of the water supply may not be necessary. Assessments should be conducted using subacute guidance values (SGVs).

In vivo mutagenicity assessment of styrene in MutaMouse liver and lung.

Background: Styrene (CAS 100-42-5) is widely used as polystyrene and acrylonitrile-butadiene-styrene resin such as plastic, rubber, and paint. One of the primary uses of styrene is food utensils and containers, but a small amount of styrene transferred into food can be ingested by eating. Styrene is metabolized into styrene 7,8-oxide (SO).

Initial hazard assessment of ethyl(dimethyl)(tetradecyl)ammonium ethyl sulfate: Genotoxicity tests and combined repeated-dose and reproductive/developmental toxicity screening in rats.

Ethyl(dimethyl)(tetradecyl)ammonium ethyl sulfate, used in laundry detergents, shampoos, and body soaps, is classified by the Japanese Chemical Substances Control Law as a priority assessment chemical substance for environmental effects. However, its toxicity data for human health are insufficient. This study evaluated this chemical under the Safety Examination of Existing Chemicals and Safety Programmes of the Ministry of Health, Labour and Welfare (MHLW).

Energy losses at three-way circular drop manholes under surcharged conditions.

Energy loss at manholes is of importance in the design of storm sewer networks and in flood-analysis. Some researchers have already investigated the energy loss at three-way manholes under surcharged conditions. However, formulation to calculate the energy loss at manholes, including all variables of structural elements of the pipes and of the manhole has not yet been accomplished.