Toxicology Publications

 Wildlife Toxicity Assessments

Last Updated: June 12, 2020

A Wildlife Toxicity Assessment (WTA) uses a standard method for developing toxicological profiles and toxicity reference values (TRVs) for military-related substances that may pose risks to wildlife.

The APHC has implemented the Standard Practice in Technical Guide 254 (TG 254) for environmental chemicals of military concern. The Standard Practice is primarily intended for use by APHC to generate wildlife Toxicity Reference Values (TRVs) that are defensible, and to provide a standard set of information for practitioners in the field. If a TRV relevant to a particular Army Environmental Risk Assessment (ERA) has been generated by APHC using this methodology, then its use is expected unless an alternative can be reasonably defended.

The program has been implemented using a phased approach, focusing on the highest-priority chemicals first. Other U.S. Army and military entities are encouraged to use this Standard Practice and our Wildlife Toxicity Assessment (WTA) reports within their ERA programs.


Picric Acid WTA 

Picric acid (2,4,6-trinitrophenol; CAS No. 88-89-1) has been used as an explosive and rocket fuel component for military applications, specifically in boosters, fuses, and armor-piercing shells.  It is moderately soluble in water and is predicted to have limited mobility in soil.  A lack of available toxicity data has limited the derivation of toxicity reference values to the following:

Ingestion for mammals, NOAEL- and LOAEL-based, with low confidence.


Mono-Nitrophenols WTA

Nitrophenols may be released into the environment during their use as organic intermediates and indicators. 4-nitrophenol is an intermediate in the synthesis of a variety of organic compounds, which are used to manufacture pesticides, fungicides, paints, dyes, leather preservatives, and drugs.

This WTA includes TRVs for 4-nitrophenol as follows: Ingestion for Class Mammalia, Dermal for Class Mammalia, Ingestion for Class Aves.


Mixed Xylenes

Xylene, also known as dimethyl benzene or "mixed xylenes," is a chemical mixture appearing as an aromatic hydrocarbon that exists in three isomeric forms: ortho-, meta-, and para-xylene (or 2-, 3-, and 4-xylene).They are blended into gasoline and used to manufacture a variety of products from perfume to pesticides. The xylene isomers are readily degraded in the atmosphere, primarily by photo-oxidation. In soil and water, the meta- and para- isomers are readily biodegraded under a wide range of aerobic and anaerobic conditions, but ortho-xylene is more persistent.

This WTA includes TRVs as follows: Ingestion in Class Mammalia, Inhalation in Class Mammalia.