Office of Research and Development (ORD). Based in Washington DC, ORD is run by Assistant Administrator Paul Anastas, whom you may have heard known as the "Father of Green Chemistry" for his research on "the design, manufacture, and use of minimally-toxic, environmentally-friendly chemicals." As its name suggests, ORD is in the forefront of doing research on a variety of fronts.
One of the things done at ORD is the provision of research resources such as the ToxCast program, and databases of chemical data, such as the IRIS and ECOTOX databases.
ECOTOX, which is short for "ecotoxicology" data such as toxicity to fish, invertebrates and aquatic plants, as well as terrestrial organisms, is a resource open to the public, industry, and academics. It "integrates three previously independent databases...into a unique system which includes toxicity data derived predominately from the peer-reviewed literature." And it is easy to use. Assuming you know something about the chemicals you are looking for and how to interpret the toxicity results you'll obtain.
Users can click on the "Quick Database Query" to hunt for test results on specific chemicals, or use the "Advanced Database Query" to fine tune your search. You can run just the aquatic search, or just the terrestrial search, or both. The results come in table form for easy scanning, with a "View Details" link to more information about the study, including dose response information, application frequency, details about the test species and exposures, etc. And most importantly, the database tells you what published study the data came from so you can look up the original source (which I highly recommend).
ECOTOX is just one of several databases made accessible by EPA and other agencies. Periodically I will mention them here so start bookmarking!