oEPA
www.epa.gov/ord
science in ACTION
BUILDING A SCIENTIFIC FOUNDATION FOR SOUND ENVIRONMENTAL DECISIONS
Aggregated Computational Toxicology Resource (ACToR)
U.S. EPA'S PUBLICALLY AVAILABLE CHEMICAL TOXICITY DATA WAREHOUSE
Tens of thousands of chemicals are
currently in commerce, and
hundreds more are introduced every
year. Because current chemical
testing is expensive and time
consuming, only a small fraction of
chemicals have been adequately
assessed for potential risk.
The U.S. Environmental Protection
Agency is revolutionizing this
current approach to chemical
toxicity risk assessment through its
Computational Toxicology Research
Program (CompTox). The program
uses innovative research that
integrates advances in molecular
biology, chemistry and computer
science to more effectively and
efficiently rank chemicals based on
potential risks. Other chemical
testing processes are time
consuming and can cost millions of
dollars. CompTox's tools can screen
a large number of chemicals, at a
cost of ~20K per chemical, in a very
short amount of time.
CompTox has a package of decision-
support tools that help guide
chemical information, risk, hazard
and exposure. Many of these tools
are publically available. ACToR
(Aggregated Computational
Toxicology' Resource) data
warehouse is one of these tools that
is available online at
www.epa. gov/actor.
ACToR is made up of 500 public
data sources on over 500,000
chemicals and it provides
information on chemical exposure,
hazard and potential risks to human
health and the environment.
It can be used to query a specific
chemical and find all available
public hazard, exposure and risk
assessment data as well as
previously unpublished studies
related to cancer, reproductive and
developmental toxicity.
ACTor links to a chemical toxicity
reference database called ToxRefDB
(http://actor.epa. gov/toxrefdb) w hich
allows scientists and the interested
public to search and download
thousands of toxicity testing results
on hundreds of chemicals.
ToxRefDB provides detailed
chemical toxicity data in a publically
accessible searchable format.
ToxRefDB contains mammal
toxicity information that when
combined with other sources of
information, such as exposure and
metabolism, form the basis for
pesticide risk assessments.
Using ACToR, scientists and others
who are interested can also access
data from another EPA chemical
screening tool called ToxCast™.
ToxCast™ is a multi-year, multi-
million dollar effort that uses
advanced science tools to help
efficiently understand biological
processes impacted by chemicals
that may lead to adverse health
effects.
ToxCast™ currently includes 500
fast, automated chemical screening
tests that have assessed over 300
environmental chemicals. ACToR
allows users to take advantage of
this linkage to find and download
these results.
Other CompTox decision support
tools and research projects include
DSSTox, ExpoCast, Virtual Liver,
Virtual Embiyo, ToxPi and Tox21.
EPA's CompTox program goal is to
provide fast automated tests for
screening and assessing chemical
exposure, hazard and risk. Housed
within EPA's Office of Research
and Development, CompTox is
composed of three main elements.
The largest component is the
National Center for Computational
Toxicology (NCCT) which was
established in 2005 to coordinate
research on chemical screening and
prioritization, informatics and
systems modeling.
The second element consists of
related activities in the National
Health and Environmental Effects
Research Lab (NHEERL) and the
National Exposure Research Lab
(NERL). The final component
consists of the academic centers
working on various aspects of
computational toxicology' funded by
the EPA Science to Achieve Results
(STARS) program.
For more information:
www. epa. go v/ncct
www.epa. gov/actor
http ://actor. epa. gov/toxrefdb
Contact:
Monica Linnenbrink
Office of Research & Development
National Center for Computational
Toxicology
919-541-1522
linnenbrink.monica@epa.gov
1
U.S. Environmental Protection Agency
Office of Research and Development

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