EPA to Initiate Chemical Safety for Sustainability Plan

The USEPA is set to launch a Chemical Safety for Sustainability initiative.  The plan is to use innovative approaches to assess chemical hazard and exposure so this can be accurately communicated to the public.  According to their web site:

EPA scientists and their partners are embracing the principles of green chemistry to produce safer chemicals. They are also integrating a diversity of scientific disciplines to develop new prediction techniques, pioneering the use of innovative technologies for chemical toxicity testing, and designing tools to advance the management of chemical risks. Chemical safety for sustainability includes research in computational toxicology, nanotechnology, endocrine disrupting chemicals, human health, and pesticides.

As part of this ongoing process EPA recently made available two new chemical databases - ToxCastDB and ExpoCastDB.  These supplement the ToxCast robotic screening testing program started earlier by EPA.  The most recent announcement of the Chemical Safety for Sustainability initiative was made during the first meeting of the National Research Council's Committee on Science for EPA's Future, part of the National Academies of Sciences.


The three main areas of focus for the program are:

• Providing scientific knowledge, tools and models for integrated evaluation strategies
• Improving assessment and informing management for chemical safety
• Targeting high priority research needs for immediate and focused attention

EPA Makes Available Two New Chemical Toxicity Databases

The USEPA has announced that it is making available two new databases to make it easier for people to find chemical data.  One database is the Toxicity Forecaster database (ToxCastDB) containing toxicity information.  The other is a database of chemical exposure studies (ExpoCastDB), which can be used to evaluate how much chemical to which people may be exposed.  Both are searchable.

The Toxicity Forecast database (ToxCastDB) can be used to download toxicity data from more than 500 rapid chemical tests that have been conducted on more than 300 environmental chemicals.  "ToxCast uses advanced scientific tools to predict the potential toxicity of chemicals and to provide a cost-effective approach to prioritizing which chemicals of the thousands in use require further testing."  Another 700 chemicals are currently being screened using ToxCast, with the data expected to be available by next year.

The ExpoCast database "consolidates human exposure data from studies that have collected chemical measurements from homes and child care centers."  According to EPA's press release, "data include the amounts of chemicals found in food, drinking water, air, dust, indoor surfaces and urine."  Additional external and internal chemical exposure data will be added as they become available. 

The new databases link together two important pieces of chemical research — exposure and toxicity data — both of which are required when considering potential risks posed by chemicals. The databases are connected through EPA’s Aggregated Computational Toxicology Resource (ACToR), an online data warehouse that collects data on over 500,000 chemicals from over 500 public sources.

Users can now access 30 years worth of animal chemical toxicity studies that were previously only found in paper documents, data from rapid chemical testing, and various chemical exposure measurements through one online resource. The ability to link and compare these different types of data better informs EPA’s decisions about chemical safety.
 

More information and links to the databases can be found on the EPA web site.

EPA Brings to 1000 the Number of Chemicals Being Tested with ToxCast

Perhaps lost in all the attention with the REACH deadline was an announcement last week by the USEPA that ToxCast screening program has "entered a new phase," in which it will add another 700 chemicals for testing "potential toxicity to people and the environment."  About 300 chemicals, mostly pesticides, were tested in the first phase, which puts chemicals through a series of fast, automated assays to screen for possible toxicity.  The hope is that ToxCast will be able to rapidly screen the roughly 85,000 chemicals on the TSCA Inventory, as well as screen new chemicals before they are put on the market.  Those chemicals for which ToxCast suggests some concern would be put into a more comprehensive evaluation process.

More information on ToxCast can be found here.

ToxCast employs a battery of rapid assays. Rather than rely on animal testing to discern toxicity, the battery includes tests that look at such things as gene expression, real-time electronic sensing, in vitro genomics, biochemical markers, and for those that want to see actual organisms, zebra fish development.

More information on the chemicals being tested can be found here and more information on EPA's computational toxicology program is here.

US Agencies Work Together to Develop Chemical Screening Methods

One of the big questions regarding the new TSCA reform discussions is how exactly will companies meet any data obligations imposed by the new law. In the past any "data" request was expected to be filled by animal testing, but the animal welfare advocates and a realization of the limitations of animal testing have led many to look for alternative testing techniques.

The Tox21 collaboration merges the resources (research, funding and testing tools) of several US agencies "to develop ways to more effectively predict how chemicals will affect human health and the environment." The agencies include the EPA, the National Institute of Environmental Health Sciences (NIEHS) National Toxicology Program (NTP), the National Institute of Health (NIH) Chemical Genomics Center (NCGC), and most recently the Food and Drug Administration (FDA).

Through the collaboration the agencies hope to develop methods to screen all chemicals for risk quickly, efficiently, and in most cases without the use of animal testing. About 2,000 chemicals "have already been screened against dozens of biological targets," with hopes of getting that number up to five times that much by the end of this year. Eventually all 85,000+ chemicals on the market will have had at least an initial screening, which will help prioritize any chemicals of concern for more closer analysis.

A major component of the Tox21 collaboration is development of rapid and automated methods, which is the focus of a testing program called ToxCast. Many of these methods use sensitive cell culture and even genomic markers to screen for toxicity rather than going directly to standard animal testing. The idea is "high-throughput," i.e., screening a lot of chemicals fast so that those that are clearly not toxic can be put aside, those that are clearly very toxic can be prioritized, and those that are somewhere in the middle can get more targeted testing to address the specific questions raised.