March 16, 2016 by Owen Green & Ed Stutt


Owen Green and Ed Stutt, two of wca's principal consultants, are attending the Society of Toxicology Annual Meeting and ToxExpo at the New Orleans Ernest N. Morial Convention Center and their round-up of Day 2 is detailed.

Inside the conference hall

Owen presented his poster entitled “Local reactions to Subcutaneous Injection of HFAs”. There was good interest in the content from veterinarians and those wanting to know more about our abilities at wca to obtain sufficient data in order to make safety/risk assessments in such niche areas.

Owen with his poster "Local reactions to Subcutaneous Injection of HFAs"

Owen and Ed attended a Special Symposium on ‘Bioactivity-Based Margin of Exposure Safety Assessment’. In the US and Canada there are programmes to screen/prioritise chemicals for further assessment based on biological pathway based hazard identification; this methodology uses in vitro measurement of bioactivity perturbations as sentinel responses as opposed to the traditional toxicological approach of in vivo studies to measure dose-response relationships for the apical effect. The results from high throughput in vitro testing systems have been combined with estimates of human exposure to generate exposure:activity ratios (EARs) or bioactivity:exposure ratios (BERs) which have been compared to margin of exposure (MoE) estimates generated using Bench Mark Doses (BMDs) from traditional toxicological studies and the same exposure estimates for respective chemicals. Comparison of results from the two techniques for a limited number of substances, and phthalates in particular, validates the use of bioactivity-based in vitro methods for screening purposes to highlight a risk-based potential for concern.

A selection of the posters