NWRC Chemical Effects Database

About the Data

The majority of the data comprising the NWRC Chemical Effects Database originated from two sources:

  1. In the late 1950s, the predecessor to the NWRC, the U.S. Fish and Wildlife Service's Denver Research Center (DRC), began a 30-year project to test chemical compounds for bioactivity and potential use as repellents, deterrents, markers, toxicants, emetics, antiemetics, immobilizing agents, tranquilizers, chemosterilants, and reproductive inhibitors. Tests were conducted on a variety of wild and domestic plants, mammals, and birds.

    Data generated from this work were compiled into the "DRC Chemical Tracking System." Approximately 6,800 DRC numbers were assigned to over 6,100 known and unknown chemicals that were submitted to the DRC or its successors during the program. The chemicals tested were received from cooperating chemical, pesticide or drug companies, purchased from chemical/drug supply houses, or contributed by other government organizations or individuals for testing. A portion of this data has been published and is accessible by searching the on-line Toxicity Database. Primary literature includes Schafer et al. (1983) and Schafer and Bowles (1985 and 2004).

  2. Repellent and toxicity screening efforts with approximately 7,000 chemicals on rats and other mammals were conducted by J. B. DeWitt, a researcher at the Denver Research Laboratories (predecessor to DRC), and scientists at the Patuxent Wildlife Research Center (PWRC). Studies were conducted for the U.S. Army Chemical Corps, Natick Laboratories, and other cooperators. These were assigned codes beginning with a "DR" (for DeWitt Research) designation. Work under the DR code occurred from 1943 through 1959. Some of these data are reported in publications; (DeWitt et al. 1953, Bowles et al. 1974). The records for many of these tests and a written listing of the results of testing conducted from 1959 through 1960 were transferred to the DWRC in 1965 and reside in the NWRC archives.
Test organisms include the following taxonomic groups:

Amphibians - Bull frogs (Rana catesbeiana) used in these tests were live-trapped, donated, or purchased from various sources (Tucker and Crabtree 1970).

Birds - Birds used in these tests were wild-trapped, purchased, or captive reared. The test procedures were described in detail in Schafer et al. (1983).

Mammals - Mammals used in these tests were wild-trapped, purchased, or captive reared. The basic test procedures were developed by Kverno (1954), Kverno and Hood (1963), and Kverno et al. (1967), and are also summarized by Schafer and Bowles (1985).

Plants - Plants used in these tests were reared in the greenhouse to the stage of development required for testing. Seeds were purchased from commercial sources. The test procedures used have previously been described in detail by Kverno (1954), Kverno and Hood (1963) and Kverno et al. (1967).

Searching the Database:

The database is searchable by:
Chemical Abstract System (CAS) Number
Chemical Name
Data Type (i.e., toxicity, repellency, immobilization, etc.)
Source (NWRC Archive record locator)
Mode of Administration (i.e., oral, dermal, etc.)
Organism Type (mammals, birds, amphibians, plants)
Species Common Name
Species Scientific Name
Test Method (approximately 20 test methods are available to search)
Test Result (variable range of values selection option)

In addition to the on-line data, the entire database including unpublished data, is currently searchable by NWRC staff. For more information about the database or to conduct unpublished data searches, please direct inquiries to For information regarding the raw data archives, please contact


Bowles, W.A., V.A. Adomaitis, J.B. DeWitt, and J.J. Pratt Jr. 1974. Relationship between chemical structure and rat repellency. II. Compounds screened between 1950 and 1960. U.S. Army, Natick Labs Technical Report 75-11-FEL. Natick, Massachusetts, USA.

DeWitt, J.B., E. Bellack, C.W. Klingensmith, J.C. Ward, and R. Treighler. 1953. Relationship between chemical structure and toxic action on rats. Chemical-Biological Coordination Center, National Research Council, Washington D.C., USA.

Kverno, N.B. 1954. Development of better seed protectants. Journal of Forestry 52:826-827.

Kverno, N.B. and G.A. Hood. 1963. Evaluation procedures and standards; chemical screening and development for forest wildlife damage. U. S. Fish and Wildlife Service, Denver Wildlife Research Center Report.

Kverno, N.B., G.A. Hood, and W.E. Dodge. 1967. Development of chemicals to control forest wildlife damage. Proceedings of the Society of American Foresters 65:222-226.

Schafer, E.W. Jr., and W.A. Bowles Jr. 1985. Acute oral toxicity and repellency of 933 chemicals to house and deer mice. Archives of Environmental Contamination and Toxicology 14:111-129.

Schafer, E.W. Jr., and W.A. Bowles Jr. 2004. Toxicity, Repellency of Phytotoxicity of 979 Chemicals to Birds, Mammals and Plants. Research Report No. 04-01. National Wildlife Research Center, Fort Collins, Colorado. 118 p.

Schafer, E.W. Jr., W.A. Bowles Jr., and J. Hurlbut. 1983. The acute oral toxicity and repellency and hazard potential of 998 chemicals to one or more species of wild and domestic birds. Archives of Environmental Contamination and Toxicology 12:355-382.

Tucker, R.K. and D.G. Crabtree. 1970. Handbook of toxicity of pesticides to wildlife. U.S. Fish and Wildlife Service, Resource Publication No. 84. 131 pp.

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