Download PDF
November 4, 2010

Draft EDSP Guidance Document Available for Public Review and Comment

The ACTA Group

The U.S. Environmental Protection Agency (EPA) announced in a November 4, 2010, Federal Register notice the availability for public review and comment of a draft guidance document entitled, “Weight-of-Evidence Guidance Document: Evaluating Results of EDSP Tier 1 Screening to Identify Candidate Chemicals for Tier 2 Testing.” According to EPA, the purpose of the draft guidance document is “to set forth some general principles, criteria, and considerations EPA generally believes to be relevant using a weight-of-evidence (WoE) approach to evaluate data submitted as part of EPA’s?Endocrine Disruptor Screening Program (EDSP)” Tier 1 screening assays. The draft guidance is available online. Comments are due January 3, 2011.

In the Federal Register notice, EPA summarizes the EDSP as a “two-tiered paradigm for screening and testing chemicals with the potential to interact with the endocrine system.” EPA announced the final list of 67 chemicals selected for Tier 1 screening on April 15, 2009. Tier 1 screening is intended to identify substances that have the potential to interact with the estrogren, androgen, or thyroid hormonal systems. The purpose of Tier 2 testing is to identify further and characterize chemical-induced interactions with estrogren, androgen, or thyroid hormonal systems for risk assessment. EPA states that it expects the diversity in endocrine endpoints within and among the Tier 1 screening assays to provide corroborating information and support a WoE evaluation to yield a decision as to whether the chemical indentified in Tier 1 requires additional testing in Tier 2.

EPA’s final list of chemicals selected for Tier 1 screening includes:

Chemical NameCAS Number
2,4-D94757
4,7-Methano-1H-isoindole-1, 3(2H)-dione,2-(2-ethylhexyl)-3a,4,7,7a-tetrahydro-113484
Abamectin71751412
Acephate30560191
Acetone67641
Atrazine1912249
Benfluralin1861401
Bifenthrin82657043
Butyl benzyl phthalate85687
Captan133062
Carbamothioic acid, dipropyl-, S-ethyl ester759944
Carbaryl63252
Carbofuran1563662
Chlorothalonil1897456
Chlorpyrifos2921882
Cyfluthrin68359375
Cypermethrin52315078
DCPA (or chlorthal-dimethyl)1861321
Diazinon333415
Dibutyl phthalate84742
Dichlobenil1194656
Dicofol115322
Diethyl phthalate84662
Dimethoate60515
Dimethyl phthalate131113
Di-sec-octyl phthalate117817
Disulfoton298044
Endosulfan115297
Esfenvalerate66230044
Ethoprop13194484
Fenbutatin oxide13356086
Flutolanil66332965
Folpet133073
Gardona (cis-isomer)22248799
Glyphosate1071836
Imidacloprid138261413
Iprodione36734197
Isophorone78591
Linuron330552
Malathion121755
Metalaxyl57837191
Methamidophos10265926
Methidathion950378
Methomyl16752775
Methyl ethyl ketone78933
Methyl parathion298000
Metolachlor51218452
Metribuzin21087649
Myclobutanil88671890
Norflurazon27314132
o-Phenylphenol90437
Oxamyl23135220
Permethrin52645531
Phosmet732116
Piperonyl butoxide51036
Propachlor1918167
Propargite2312358
Propiconazole60207901
Propyzamide23950585
Pyridine, 2-(1-methyl-2-(4- phenoxyphenoxy)ethoxy)-95737681
Quintozene82688
Resmethrin10453868
Simazine122349
Tebuconazole107534963
Toluene108883
Triadimefon43121433
Trifluralin1582098

Given EPA’s intent to use the WoE guidance to evaluate broadly Tier 1 screening data to determine whether additional Tier 2 testing is necessary, manufacturers of the chemicals selected for Tier 1 screening should review the draft guidance to ensure it will allow EPA to analyze Tier 1 screening data accurately to determine which chemicals will be selected for Tier 2.

Comment

The guidance itself notes that this approach is not meant to be any different in its application to the endocrine program than from other areas of scientific assessment where EPA utilizes a WoE approach. What is perhaps most interesting, is that this announcement acknowledges that the approach will be used to evaluate the “other scientifically relevant information (OSRI)” — which has been a controversial element of EPA’s endocrine testing program. Specifically, many interested parties have insisted that if EPA fairly and fully evaluates the body of existing data already developed and submitted to EPA, the need for the now-required “lower-tier” endocrine effect tests would not be justified. As a result, comments submitted on the current notice will allow another advocacy opportunity to advance the position that, in many cases, using a WoE approach in evaluating existing data will lead EPA to conclude that additional new testing is unnecessary.