The goal of this contract is to provide support of National Toxicology Program (NTP) hazard identification (or hazard assessment) activities targeted toward the prevention of diseases or adverse effects caused by environmental exposure to chemical or physical agents. This contract includes a varied array of test materials and classes of test materials that are to be tested via the inhalation route of exposure, some are vapors while others are liquid or solid aerosols. This contract includes prechronic studies to evaluate the fibrotic potential and lung burden of 6 abrasive blasting agents (ABA) which includes blasting sand, coal slag, garnet, crushed glass, steel grit, and specular hematite. Abrasive blasting agents are of human health concern becasue of their content of Si and as replacements for crystalline silica. The 14-day studies have been completed and reported for all ABAs except steel grit. Steel grit studies have been put on hold depending upon whether the bulk material can be milled to meet study needs. In addition this contract includes 14-day and 90-day toxicity studies for 9 metal working fluids (MWF) (Cimstar 3800, Trim SC210, Clearedge 6584, Cimtech 310, Syntilo 1023, Trim 229, Superedge 6768, Cimperial 1070, and Trim VX. MWFs are used extensively in occupational settings and present a possible heal risk to individuals using them. The chemistry and exposure generation and monitoring phase are in progress for Syntillo 1023. Cimstar 3800 and Trim SC210 90-day studies have been completed and reported. The 14-day studies were canceled and all will go directly to 90-day studies. Trim VX 90-day studies are currently in-life and the 2-year studies of Cimstar 3800 are in-life. The contract also includes 14-day and 2-year studies of antimony trioxide. Antimony trioxide has been shown to be a carcinogen in some rodent species; however better controlled exposures and additional species need to be utilized to determine conclusively the carcinogenic potential of antimony trioxide so that the results can be used in human risk assessment. The 14-day studies have been completed and reported and the 2-year study is scheduled to start the 4th quarter of FY-08. The contract also includes 90-day studies of C60 fullerene nanomaterials or 50nm and 1 micron sizes. Nanomaterials are emerging new technologies with little or no known toxicity and carcinogenicity studies having been performed; therefore the potential for human health effects is unknown. The in-life portion of the studies have been completed and are currently in the report writing phase. The contract also includes testing two artificial butter flavoring agents (ABAs, acetoin, 2,3-butanedione) in 14-days (acetoin) and 90-day studies (acetoin, 2,3-butanedione). ABAs have been linked to occupational exposure and human health effects including bronchiolitis obliterans. Animal studies are neede to determine the potential for human health effects to individual ABAs. The 2,3-butanedione 90-day study is in-life and the 14-day acetoin study is scheduled to start 1st quarter of FY-09. The contract also includes testing ortho-phthalaldehyde (OPA) in 90-day studies which are scheduled to start the 1st quarter of FY-09. OPA is being utilized as a replacement for the known rodent carcinogen gluteraldehyde therefore animal toxicity data is needed to determine potential for human heal effects with OPA. Keywords lung burden, fibrosis, toxicity and carcinogenicity, metal working fluids, abrasive blasting agents, fullerenes, nanomaterials, artificial butter flavorings, antimony trioxide, ortho-phthalaldehyde
