Toxicity of Nitro-Heterocyclic and Nitroaromatic Energetic Materials to Folsomia candida in a Natural Sandy Loam Soil

In conjunction with stakeholders, the U.S. Environmental Protection Agency (USEPA) developed ecological soil screening level (EcoSSL) values for contaminants at Superfund sites. EcoSSL values are derived by using published data that is generated from laboratory toxicity tests with test species relevant to soil ecosystems. After performing an extensive literature review (USEPA, 2005), the EcoSSL workgroup determined that insufficient information was available on energetic materials (EMs) to generate EcoSSL values for soil invertebrates. In this study, we produced benchmark data to support the development of soil invertebrate EcoSSL values for RDX, HMX, 2,4-DNT, 2,6-DNT, and TNB. We used the Folsomia Reproduction Test, which uses an ecologically relevant test species and includes at least one reproductive measurement endpoint. Definitive toxicity tests conducted with freshly amended EMs in soil showed that EM toxicity, based on 20% effect concentration values for the production of juveniles, was TNB 2,6-DNT 2,4-DNT RDX HMX; with weathered-and-aged EMs in soil, EM toxicity was 2,6-DNT 2,4-DNT TNB RDX HMX. These study results will be provided to the EcoSSL workgroup for review and inclusion in the EcoSSL database, and for developing EcoSSLs for RDX, HMX, 2,4-DNT, 2,6-DNT, and TNB. The original document contains color images. Prepared in collaboration with the National Research Council Canada, Montreal, Quebec.