Final Decision to Certify Hazardous Waste Environmental Technology
Ohmicron Environmental Diagnostics, Inc.
TNT RaPID Assay®
(Trinitrotoluene in Water and Soil)
The following is excerpted from:
CALIFORNIA REGULATORY NOTICE REGISTER
The California Environmental Protection Agency, Department of Toxic Substances Control (DTSC) has made a final decision to certify the following company's hazardous waste environmental technology:
Chapter 412, Statutes of 1993, Section 25200.1.5, Health and Safety Code, enacted by Assembly Bill 2060 (AB 2060 by Assemblyman Ted Weggeland), authorizes DTSC to certify the performance of hazardous waste environmental technologies. Only technologies that are determined not to pose a significant potential hazard to the public health and safety of to the environment when used under specified operating conditions and which can be operated without specialized training and with minimal maintenance may be certified. Incineration technologies are explicitly excluded from the certification program.
The purpose of the certification program is to provide an in-depth, independent review of technologies at the manufacturer's level to facilitate regulatory and end-user acceptance and to promote and foster growth of California's environmental technology industry.
DTSC makes no express or implied warranties as to the performance of the manufacturer's product or equipment. The end-user is solely responsible for complying with the applicable federal, state, and local regulatory requirements. Certification does not limit DTSC's authority to require additional measures for protection of public health and the environment.
By accepting certification, the manufacturer assumes, for the duration of certification, responsibility for maintaining the quality of the manufactured equipment and materials at a level equal or better than was provided to obtain certification and agrees to be subject to quality monitoring by DTSC as required by the statute under which certification is granted.
DTSC's notice to certify was published in the California Regulatory Notice Register Volume 96, No. 6-Z, pp 197 and 199-201. The DTSC's final certification shall be effective from March 11, 1996 to March 11, 1999.
Additional information supporting DTSC's final certification decisions is available from:
A description of the certified technology, the final certification statement and the certification limitations follows.
Ohmicron Environmental Diagnostics, Inc.
Certification Statement - Technology Specifications
Under the authority of Section 25200.1.5 of the California Health and Safety Code, DTSC hereby certifies the TNT RaPID AssayR (Trinitrotoluene in Water and Soil) manufactured by Ohmicron Environmental Diagnostics, Inc. as a Measurement Technology. The Ohmicron TNT RaPID Assay System uses enzyme-linked immunosorbent assay (ELISA) technology. It differs from other systems in that polyclonal antibodies are supplied attached to magnetic particles. TNT in water is assayed directly; for soils, the system uses extraction with alkaline methanol. The immunoassay system is semi-quantitative. Provided that the materials are used properly, detection is possible at 0.25 to 5.0 ppb in water and 0.25 to 5.0 ppm in soil; ranges can be extended upward by dilution of the extracts.
Quantitative readings about a selected target level are obtained in a microprocessor-equipped, hand-held, battery-operated photometer or a compact table top photometer supplied by the manufacturer, or a standard laboratory photometer. The calibration is not biased, but the user is instructed to select target levels so as to determine the degree of confidence in avoiding false negative results. The reaction with other nitroaromatics is insignificant except for 1,3,5-trinitrobenzene (a contaminant in technical grade TNT). HMX, RDX, Dinoseb and 2,4-dinitrophenol and the mononitroaromatics do not interfere. Differences in the extraction efficiency of TNT from various soils may cause positive or negative errors in the immunoassay results. Users should evaluate these factors before attempting to quantify results.
Great care is required and established safety measures must be observed in sampling and handling soil containing explosives. As with similar assays, certain temperature controls are required for reagent storage and for carrying out the assay. The assay should be used only by trained individuals to reduce operator-caused variability.
Limitations of Certification
DTSC makes no express or implied warranties as to the performance of the manufacturer's product or equipment. Nor does DTSC warrant that the manufacturer's product or equipment is free from any defects in workmanship or material caused by negligence, misuse, accident, or other causes.
DTSC believes, however, that the manufacturer's product or equipment can achieve performance levels set out in this Certification. Said belief is based on a review of the data submitted by the manufacturer and other information, and is based on the use of the product in accordance with the manufacturer's specifications.
This Certification is issued as part of a pilot project to expedite the California Environmental Technology Certification Program. As a result, this Certification is subject to the conditions set out in the regulations to-be-developed, such as the duration of the Certification, the continued monitoring and oversight requirements, and the procedures for certification amendments, including decertification.
By accepting this Certification, the manufacturer assumes, for the duration of the Certification, responsibility for maintaining the quality of the manufactured materials and equipment at a level equal or better than was provided to obtain this Certification and agrees to be subject to quality monitoring by DTSC as required by the law under which this Certification is granted.
Basis for Certification
The Documentation submitted by the manufacturer and other studies are listed in the evaluation report on which this certification is based. The manufacturer has asserted that certain materials contain proprietary information and therefore should not be subject to public disclosure.
The assay was developed for the semiquantitative determination of TNT. A semiquantitative determination will provide a response, interpreted as either positive or negative, at one or several predetermined detection or target levels. Target levels are usually chosen to have relevance to a specific situation (such a regulatory action or cleanup level).
A comprehensive process of developing data quality objectives (DQO) was published by U.S. EPA under the U.S. Superfund Program. It provides guidance for analytical method QA/QC as applied to field investigations for contaminated soils. The process is intended for site-specific sampling plans. Here the immunoassay would generally qualify as a Level 2 (field analysis) method, subject to confirmation by a Level 3 method (confirmation and quantification, e.g., EPA Method 8330) applied predominantly to positive results. We recommend that minimum quality control should include a method blank and duplicates at 10 to 20 percent, or one per batch or per matrix, whichever is the more frequent, in addition to the samples required for confirmation. The use of proficiency evaluation and spiked samples should depend on project-specific needs.
U.S. EPA SW-846 Method 8330 is available and currently approved for establishing or confirming concentrations of TNT.
Screening and Preliminary Site Investigations
The immunoassay can assist in preliminary site investigations (Phase I), if there are compelling historical data to indicate the presence of TNT as in explosives manufacturing and handling and ordnance open burn and detonation operations. If used on samples with unknown potential for analytical interferences and matrix effects, confirmatory analysis is needed for every positive immunoassay result. The user should be aware of the reactions given by chemically related nitroaromatics which are common contaminants and breakdown products of TNT. No negative determinations can be made without taking into account the specificity of the assay and its possible susceptibility to interferences and matrix effects. In the absence of other regulations and guidelines, we recommend that assay results be confirmed in the following manner:
If appropriate protocols are followed, the immunoassay can be used to advantage to classify contaminated soils as to low, medium, or high contamination and to determine which samples would provide the most information from laboratory analysis.
Site Investigations and Remedial Actions
Here the testing is expected to proceed under a site-specific Quality Assurance Project Plan (QAPP). Immunoassay and other field measurements will be bracketed in time and space by qualitative and fully quantitative analyses. Generally, a site is first characterized by the use of approved, fully qualitative and quantitative analytical methods as to the nature and level of contamination in key sampling locations and as to the presence of substances that may interfere with the use of the immunoassay. After such initial characterization, the immunoassay can be used in the comprehensive mapping of the site with respect to identified contaminant(s) to which the immunoassay responds. The percentage of samples that would be confirmed by another approved, fully quantitative method would be as stipulated in the QAPP; the project manager could call for additional confirmatory testing if such a need is indicated in the course of the investigation. During site cleanup, the QAPP would provide for use of the immunoassay to monitor progress. Confirmatory laboratory testing would occur before a decision on site closure is made.
DTSC's Certification is based on the technology's performance and by itself does not change the regulatory status of TNT testing; it should, however, facilitate and encourage the acceptance of this technology where a project's data quality objectives can be met by its use. To this end, DTSC's findings should contribute to a consideration of this technology in regulated activities, depending on each program's objectives and constraints. State-regulated disposal facilities may contact state permitting officers for use of the immunoassay for operational monitoring. Other local and state government permitting authorities may take this certification under consideration when making their permitting decisions. Project leaders may use this assay if it meets data quality objectives.
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File last updated: August 28, 1997