Triggers

November 14, 2017




An often-unforeseen outcome from an EPA-required study is the need to do additional studies based on the study outcomes. You may not realize that the results obtained in one EPA required study can trigger additional studies.
As an example, soil metabolism studies often generate results needed to design higher tier field dissipation studies. Plant metabolism studies can generate results needed for conducting magnitude of residue (MOR) trials. Animal metabolism studies often generate results needed for animal feeding studies. Here are three examples:
#1
A soil metabolism study will typically reveal metabolites that arise from biotic or abiotic mechanisms. As a result, new questions arise. Are there mobility or toxicity concerns for these metabolites? Is there a volatility concern? Metabolites may be long lived relative to the parent molecule. Once identified as significant, these will need to be monitored in field scale dissipation studies. TRIGGER- method development, a validated analytical method, and an independent lab validation will be required.
#2
A plant metabolism study will identify metabolites that arise either from direct plant treatments or soil applications. Are there metabolites of toxicological concern? Were they observed in a rat metabolism study? Will they be included MRL? Once identified as significant, these will need to be monitored in MOR studies. TRIGGER- method development, a validated analytical method, and an independent lab validation will be required.
#3
A goat or hen metabolism study will identify metabolites that arise following ingestion or topical applications. Are there metabolites of toxicological concern? Are they included in the tolerance expression for meat, milk, and eggs? Once identified as significant, these will need to be monitored in animal feeding studies. TRIGGER- method development, a validated analytical method, and an independent lab validation will be required.
As you can see from these three examples, lower-tiered studies need to be conducted prior to the larger scale field studies as information collected is necessary for proper design and execution of the larger, and generally more costly studies. The results you obtain can have a significant impact on the magnitude of the effort needed down the line.

To discuss this topic further, contact:

Dr. Paul Reibach
preibach@smithers.com
+1 508-295-2550
 

 

Related Tags:EPA, metabolism, MOR, soil, trials
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About The Author | Dr. Paul Reibach

Dr. Reibach is currently the Technical Director of Chemistry at Smithers Viscient in Wareham MA where he is responsible for identifying and implementing new technologies for conducting a broad range of regulated analytical chemistry studies. He received a BA in Biology from The University of Texas at Austin and a PhD in Plant Physiology from Texas A&M University. Prior positions have included Rohm and Haas Research Laboratories, Cerexagri Inc., United Phosphorus, and JRF America. At Smithers Viscient the chemistry department conducts analytical chemistry research in support of global pharmaceutical, pesticide, and specialty chemical registrations. Dr. Reibach has developed numerous residue analytical methods which have been utilized for trace level analysis of soils, crops, and animal tissues. Dr. Reibach has issued over 200 technical reports and publications that have been submitted to various regulatory agencies worldwide.

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