Toxicological support

In all cases, it is important to appropriately safeguard public health without defaulting to overly conservative actions (e.g. to nondetect ) that would divert limited resources without significant benefit. The following sections summarize toxicological support and developmental rationale for the two primary criteria of interest to community decision-makers managing response to an intentional or accidental release of nerve agent(s) to the environment. 

In this spirit we expect and look forward to provide, along with our Organic Intermediates technology, whatever services are required to make our joint success complete efficient pilot facilities, advanced analytical equipment with expert staff, toxicology and eco toxicology support, environmental services, formulation capabilities,. .. we do this throughout the world. 

In addition to being used for screening purposes for new dmg development, labeled dmgs and ligands are widely used by pharmaceutical companies for metabohc, bioavailabihty, and toxicological studies to support new dmg appHcations for FDA approval. 

Visithttp //ntp-support.niehs.nih.gov/Main Pages/Chem-HS.html. This is the site for the National Institute of Environmental Health Science. You will find MSDS-type chemical health and safety information from the National Toxicology Program. Chemical searches can be performed by chemical name, synonym, or CAS (Chemical Abstract Service) number. 

This symposium addressed several important issues in bromine chemistry. A major part has been devoted to stereochemistry and mechanism of electrophilic bromination of olefins. Other topics included new selective methods of bromination and oxybromination, brominations in presence of solid supports and catalysts, organobromine compounds as synthons, recent developments in brominated fire retardants and toxicological and environmental aspects of brominated compounds. 

Where sufficient toxicologic information is available, we have derived minimal risk levels (MRLs) for inhalation and oral routes of entry at each duration of exposure (acute, intermediate, and chronic). These MRLs are not meant to support regulatory action but to acquaint health professionals with exposure levels at which adverse health effects are not expected to occur in humans. They should help physicians and public health officials determine the safety of a community living near a chemical emission, given the concentration of a contaminant in air or the estimated daily dose in water. MRLs are based largely on toxicological studies in animals and on reports of human occupational exposure. 

Male mice exposed to 7.3 mg/kg/day for 13 weeks had significantly decreased spleen weights and decreased neutrophil counts (Hoechst 1984b), indicating that immune activity in mice may also be affected. An intermediate-duration oral MRL of 0.005 mg/kg/day was derived based on the NOAEL of 0.45 mg/kg/day for immunotoxicity identified in the Banerjee and Hussain (1986) study. In support of these positive findings, Khurana et al. (1998) observed decreased macrophage functionality, in the absence of any other apparent toxicological effects, in 1-day-old broiler chicks fed 30 ppm endosulfan in the diet for 4 or 8 weeks. 

Safe, S. (1990). PCBs, PCDDs, PCDFs and related compounds Environmental and mechanistic considerations which support the development of toxic equivalency figures. CRC Critical Reviews in Toxicology 24, 1-63. 

We would like to thank Mitch Villereal and his colleagues for their assistance and helpful discussions. This work was supported by National Cancer Institute Grants CA35541 and CA40407 to M.R.R. and National Institute of Health Toxicology Grant T32-ES07020 to E.V.W. 

Richard, A. (1995) Role of Computational Chemistry in Support of Hazard Identification (ID) Mechanism-Based SARs. Toxicology Letters, 79, 115-122. 

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