TSCA Environmental Release Application (TERA) for Modified Escherichia coli

On March 27, 2002, the Office of Pollution Prevention and Toxics approved the TSCA Environmental Release Application (TERA) under the biotechnology regulations promulgated under the Toxic Substances Control Act (TSCA). The TERA, submitted by University of North Carolina, involves field trials of a modified strain of E. coli; the TERA was given the tracking designation of R-01-0001. The microorganism will be introduced into potential sources of fecal contamination, and sampling sites in and around the source will be assayed to determine if the bacteria can be detected downstream from the release points. The eventual application of such technology would be in detection of fecal contamination sources such as sewer line leaks or overflow, groundwater, or WWTP (wastewater treatment plant) effluents. Data regarding contamination will be collected to assess compliance with state Total Maximum Daily Load plans mandated by the Clean Water Act.

Regulatory Background

The EPA requirements concerning microbial products subject to TSCA (15 U.S.C. Section 2601, et seq.) are set forth in “Microbial Products of Biotechnology; Final Regulation under the Toxic Substances Control Act” (62 FR 17910 (April 11, 1997)) and codified at 40 C.F.R. Part 725. Microorganisms resulting from the deliberate combination of genetic material originally isolated from organisms of different taxonomic genera (intergeneric microorganisms) constitute “new” microorganisms subject to TSCA Section 5 notification requirements. Persons who manufacture, import, or process intergeneric microorganisms for commercial purposes subject to EPA jurisdiction under TSCA, are required to submit a Microbial Commercial Activity Notice (MCAN). Persons conducting commercial research and development activities may submit a TERA, instead of an MCAN, before initiation of such testing. EPA conducts a review of these submissions to determine whether the intergeneric microorganisms present an unreasonable risk to health or the environment. The Agency can impose regulatory controls under section 5 of TSCA.

Summary of the Risk Assessment

Escherichia coli (E. coli), is a gram-negative bacterium that is a normal inhabitant of the intestinal tract of humans and other mammals. E. coli from normal intestinal flora are usually harmless to the host and can usually only cause opportunistic infections in humans. Some specific strains of E. coli represent primary pathogens that have an enhanced potential to cause disease. However, the pathogenicity of the recipient bacteria described in the TERA is low. In addition, the concern for pathogenicity and toxicity arising from the introduced plasmid is low.

The outer layer of all gram-negative bacteria, including E. coli, consists of lipoproteins, phospholipids, and lipopolysaccharides (LPS). The level of LPS, also known as endotoxin, has been shown to correlate with the severity of asthma. The concern for endotoxin-induced health effects associated with this TERA is lower because the limited experimental releases are not expected to result in exposures high enough to cause significant effects.

Conclusion

EPA has determined that the proposed small scale field trials of the intergeneric microorganism will not present an unreasonable risk of injury to health or the environment. In the TERA approval letter, EPA advised the submitter that this TERA was granted based on the condition that EPA review laboratory soil column studies and/or pilot field studies before releases to the environment are allowed. Specifically, the submitter must demonstrate the ability to detect the TERA substance, perform a dilution study, perform a tracer study, and do a Pilot study. The letter of approval expressed the Agency’s concerns regarding detection of the TERA substance. The submitter was also encouraged to communicate with the appropriate North Carolina environmental regulatory agency.

For a copy of the original nonconfidential TERAs and the nonconfidential approval letter, please contact the TSCA Non-Confidential Information Center (NCIC) by phone at (202) 566-0280, or by fax at (202) 566-9744.