New OECD Test Guidelines Available for Endocrine Disruptor Testing

The Organization for Economic Co-operation and Development (OECD) has
officially adopted two test guidelines for test methods to identify
substances with the potential to affect the function of the endocrine
system. Both test guidelines describe in vitro methods that do not use
animals, and the tests are appropriate for use in the U.S. Environmental
Protection Agency (EPA) Endocrine Disruptor Screening Program.

The new test guidelines are available on the ICCVAM website:
OECD Test Guideline 457: BG1Luc Estrogen Receptor Transactivation Test
Method for Identifying Estrogen Receptor Agonists and Antagonists is
available at link. (PDF)

OECD Test Guideline 455: Performance-Based Test Guideline for Stably
Transfected Transactivation In Vitro Assays to Detect Estrogen Receptor
Agonists is available at link. (PDF)

Test Guideline 457 describes the BG1Luc estrogen receptor (ER)
transactivation (TA) assays to detect ER agonist and antagonists and
provides performance standards for each assay. The test guideline was
based on data from an international validation study coordinated by the
National Toxicology Program Interagency Center for the Evaluation
ofAlternative Toxicological Methods (NICEATM). The validation study
included laboratories in the United States, Japan, and Italy.

NICEATM worked closely with the EPA to usher this method through the OECD
nomination and adoption process. The adoption of Test Guideline 457 means
that these methods may now be used in the 34 member countries of the
OECD. In July 2012, the EPA announced its acceptance of the BG1 method
as an alternative to the HeLa9903 TA assay in response to a
recommendation by the Interagency Coordinating Committee on the
Validation of Alternative Methods (ICCVAM).

Test Guideline 455 has been updated to include both the BG1 and HeLa9903
methods, and now describes general characteristics of stably transfected
transactivation in vitro assays to detect ER agonists. This
performance-based test guideline also provides standards for development
of new test methods of this type. These standardsinclude a harmonized
list of reference chemicals that should be tested during assay
development, as well as performance standards that should be met by
successful assays.