title: A TTC threshold for acute oral exposure to non-genotoxic substances.
abstract: To derive an acute TTC threshold, the correlation between Allowable Daily Intakes (ADIs, chronic values) and Acute Reference Doses (ARfDs) of pesticides evaluated in the EU was investigated and their distributions were compared. The correlation between ARfDs and ADIs was significant (p = 0.01), but weak (r(2) = 0.051). Consequently, using this approach to derive acute TTC values does not seem valid. Therefore, the distributions of ARfDs and ADIs were compared directly, in order to extrapolate from chronic to acute TTC values. This comparison made for the combined Cramer structural class II and III pesticides showed a ratio ARfD/ADI of approximately 3 at the fifth percentile of the distributions. Based on these results, it is justified to propose a TTC for acute effects for Cramer III substances by multiplying the Cramer class III TTC threshold of 90 μg/person/day with a factor 3. This leads to an acute TTC threshold based on the Munro dataset for Cramer class III substances of 270 μg/person/day.
authors: TNO, PO Box 360, 3700 AJ Zeist, The Netherlands. Electronic address: harrie.buist@tno.nl.
authors: Harrie E
authors: HE
authors: Buist
authors: TNO, PO Box 360, 3700 AJ Zeist, The Netherlands.
authors: Lisette
authors: L
authors: Krul
authors: TNO, PO Box 360, 3700 AJ Zeist, The Netherlands.
authors: Winfried R
authors: WR
authors: Leeman
mesh_terms: D016208:Databases, Factual; D004305:Dose-Response Relationship, Drug; D004781:Environmental Exposure / Q000009:adverse effects*; D005506:Food Contamination; D006801:Humans; D015233:Models, Statistical; D019055:No-Observed-Adverse-Effect Level; D010575:Pesticides / Q000009:adverse effects*; D018570:Risk Assessment; D020711:Threshold Limit Values; D018675:Toxicity Tests
chemical_list: D010575:Pesticides
keywords: ADI; ARfD; Acute TTC; Chronic TTC; Cramer class; Munro dataset; Pesticides