U.S. EPA, Contracts Management Div, Cinicnnati, OH, 45268-7001

A -- ANALYZING OF LOW DOSAGE ADDITIVITY SOL 96-115 POC Pam Legare (513-366-2015) The USEPA plans to negotiate a contract on a sole source basis with Dr. Patrick Durkin to analyze the issue of whether low dose additivity for toxic chemicals is valid for noncancer risk assessment. Negotiations shall be conducted pursuant to the authority of 41 U.S.C. 253 (c)(1), which allows for negotiation without full and open competition if there is only one responsible source. The basis for this determination is that the U.S. EPA NCEA in Cincinnati has a requirement to have a contractor with unique knowledge and experience in the analysis of chemical mixtures, calling for a blend of talents that include toxicology, statistical modeling, and knowledge of the Agency's interaction patterns methodology. The contractor must also have access to data bases that include available literature and information on toxicity of binary pairs of toxic chemicals. The proposed contractor,Dr. Patrick Durkin, has the only published research paper on interaction patterns methodology. Dr. Durkin has worked on the interaction patterns methodology and other chemical mixtures risk assessment issues for number of years. In addition, he has developed a data base, called MIXLOOK, that contains the interaction information on chemical pairs that is necessary for completion of this work. The purpose of this acquisition is to build on the methodology Dr. Durkin has already been developing by applying it to a specific area of low doses of chemicals and to use information from his data base as a basis for validation. If another contractor were used, most of Dr. Durkin's work would have to be repeated, and knowledge on the interaction patterns and methodology would have to be gained, requiring substantial additional costs to the Government. THIS IS NOT A REQUEST FOR PROPOSALS. Sources wishing to be considered must submit a qualification statement. Documentation should be submitted within 7 days of publication of this notice. (0228)

Loren Data Corp. http://www.ld.com (SYN# 0008 19960816\A-0008.SOL)