Toxicity Testing Strategies to Determine Needs and Priorities (1984) / Chapter Skim
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3. BRIEFLY FOLLOWING A CHEMICAL THROUGH AN ILLUSTRATIVE SYSTEM
3. BRIEFLY FOLLOWING A CHEMICAL THROUGH AN ILLUSTRATIVE SYSTEM
Pages 227-236
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This number links the priority-setting system with the various automated data bases on which it depends. In Stage 1, only a few fragments of information can feasibly be retrieved and processed.
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228 TSCA Inventory CTDE Data Base RTECS, EMIC, ETIC SANSS _ _ _ _ _ _ _ _ _ _ _ _ _ _ _-_ Computer ~1 STAGE 1 Compile Data - Production Volume Use Class Toxic Effects Reported Toxic Class (SAR) Decision Rules Stage 1 Processor L M H ·:-:-: ·:-:-: ·:-:-: ·_ ._....~.
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Decision: .. Rules :~:~:~:~:~:~:~:~:~:~:~:~:~: l ~ 111 ~1 Stage 2 Processor L M H Exposure Toxicity CAS 80057 - +, + Bisphenol A Uses Toxicity Fate | Mini Dossier
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230 STAGE 3 , I STAGE 4 ~ 1 fertility Assessment by Continuous Breeding Evaluation of Results Fungicide, wheat & oats Indirect food additive (packaging) Anti-corrosive for Coatings Flame Retardants Dental Fillings 203,000 Workers Exposed Teratogenicity Inadequate Sperm Abnormalities No Convincing Evidence for Carcinogenicity [.
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" category and would show some suspicion of neurotoxicity, skin sensitization, and pulmonary irritation. When the data on a given chemical have been collected from the various automated data bases, the computer implements the decison rules derived from the optimization model as the "Stage 1 processor." These computer-generated rules (described in Appendix B)
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Each expert scans the microdossier and develops a strategy for searching the appropriate data bases, compilations, and reviews, noting what sorts of information are probably most important to retrieve. In the case of bisphenol A, the exposure assessor calls for a routine printout from the Toxicity Data Bank and checks the Cosmetic Ingredient Dictionary (Estrin et al., 1982)
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not in in RTECS, no mention of MUT or CAR 2 in RTECS, mention of MUT, but not CAR 6 in RTECS, mention of ~ Stage 2: Perform search for exposure data and limited search for toxicity data Assessments Based on Data Gathered in Stage 2 Stage 3: Exposure Toxicity Data Gathering Assessments Based on Data Gathered in Stage 3 Stage 4: Recommended Testinga Medium Medium or high Dossier aST = Short-term test; LT = Long-term test High toxicity and high exposure Otherwise FIGURE 6 Decision rules used in processing example chemical bisphenol A
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either automatically from the matrix assignment or on the basis of their own judgment. These estimated probability distributions are passed to Stage 3 with the augmented minidossier containing all information gathered to date.
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In the case of bisphenol A, fertility assessment by continuous breeding of rodents is the preferred test. When the test is complete, its results are evaluated with respect to public policy and their relevance to further refinement of the selection process (Figure 5, "Feedback to Data Based.
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From page 236... ...
results can also be fed back into the specific data base on bisphenol A to determine whether further tests are justified. Although it is not shown in Figure 5, the argument for a new bioassay would be much more compelling if the short-term mutagenicity assays had proved consistently positive.
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