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Cleaning up meth contaminationMethamphetamine (meth) is an illegal stimulant drug made from cold medicine and common household chemicals. Pseudoephedrine or ephedrine, found in non-prescription cold medicines, is converted to meth using variations of two main methods, the Red Phosphorous Method and the Anhydrous Ammonia Method. Minnesota meth “cooks” have typically used variations of the Anhydrous Ammonia Method because small quantities of meth can be produced in a few hours.

During the “cook,” methamphetamine vapors and particles and other chemicals are deposited unevenly on structural surfaces and possessions throughout the building in which the meth is made. Case studies of former meth labs in Minnesota have shown that meth also penetrates materials such as wood studs, latex painted wallboard, and cement block. (See section “Former Meth Labs Studies: Impacts on Indoor Cleanup Guidance” below.)

Outdoor contamination

The production of meth in illegal “meth labs” can create environmental hazards. Meth cooks typically dispose of waste from meth labs at the production site in the following ways: dumping into indoor plumbing drains that drain either into a city sewer system or individual sewage treatment system (ISTS), dumping into plumbing that drains directly onto the soil, and/or disposing into burn or burial pits.

The primary environmental hazard is possible contamination of groundwater by volatile organic compounds (VOCs) used in the meth cooking process. In limited samplings to date, the Minnesota Pollution Control Agency (MPCA) has not yet identified levels of concern in groundwater due to meth lab-related wastes.

Minnesota legislation effective in 2005 placed restrictions on sales of the precursor drugs, ephedrine and pseudoephedrine, required to make meth. The number of new meth labs found in Minnesota has since fallen.

Guidance for meth lab cleanup

The links below provide guidance and information on proper cleanup procedures for meth lab waste and hazardous materials. MPCA is the lead state agency for outdoor investigations and remediation (cleaning and sealing).

Former Meth labs studies: Impacts on indoor cleanup guidance

Testing for meth contaminationStudies done by the MPCA with the Minnesota Department of Health’s (MDH) Public Health Laboratory were the basis of the current MDH’s Clandestine Drug Lab General Cleanup Guidance (the MDH Guidance). MDH is the lead state agency for indoor contamination assessments and cleanups. The guidance is available on the MDH Meth Lab Cleanup page.

MPCA sampled former clandestine meth labs to characterize meth deposition and penetration of meth into building materials and to provide baseline data for cleaning and sealing studies. MPCA found wipe sampling of meth contaminated materials to be problematic because sampling results from different building materials are difficult to compare. For example, different adjacent building materials (e.g., raw wood studs, cement block, metal, and latex painted sheetrock) sample differently and yield different concentrations of meth when wipe sampled. This creates difficulties in interpreting wipe sample data to determine pre- and post-cleaning effectiveness. Despite these negative aspects, wipe sampling is still often used to determine remediation adequacy.

The adopted “cleanup standard” of 1 microgram per square foot (µg/ft2 ) is not a health-based or risk-based value; that is, levels of meth above or below 1 µg/ft2 cannot be said to be either a “dangerous” or “safe” level of human exposure to meth. Much work remains in the area of health risk assessment regarding “safe” exposure levels to residual meth and other possible contaminants in former meth labs. Because of this and the difficulties of interpreting sampling results, the MDH Guidance “relies on a remediation process rather than achievement of a number …” (from MDH Guidance Section D, “Meth Risk Decisions,” p. 11).

The MDH Guidance provides bulleted actions to perform the remediation process, including removing and disposing of materials that cannot be cleaned (e.g., carpeting, ceiling tile and wallpaper), then double washing plus rinsing all surfaces and then sealing with two coats of paint or polyurethane. Minnesota case studies of former meth labs have shown that cleaning and sealing will greatly reduce human exposure to meth; yet, after the remediation process, a sampler using the Guidance’s sampling procedure for methanol-dampened wipes (see MDH Guidance, Appendix C1) sent to a certified analytical lab will almost always find low level meth residue. Because remediation effectiveness cannot be demonstrated reliably by wipe sampling, pre- and post-remediation sampling for meth is not required by MDH’s Guidance if the remediation process is followed (see MDH Guidance, p.12).

To emphasize, the structure that is thoroughly cleaned and sealed according to the MDH Guidance will have a low level of meth residual available for wipe sampling on some surfaces. Studies have shown that meth will remain, sealed into the building material beneath the paint or polyurethane; this sealed meth is not likely available to subsequent residents. Studies of the long-term stability of meth sealed into structural materials are still necessary.

Despite the problems inherent in wipe sampling for meth, sampling may be required in some cases. Careful planning of sampling locations, choice of building materials to be sampled, and interpretation of results is necessary (see, MDH Guidance, Appendix C4). For further understanding, see the links below for the studies that are the bases of these recommendations.

The following links provide an overview of the studies and implications for wipe sampling and remediation of former meth labs. Wipe Sampling, Results, and Cleaning Former Meth Labs: Minnesota Studies’ Impact on Meth Lab Cleanup Guidance is a slide show presentation with notes that guides the viewer through the studies with comment on implications for wipe sample planning and interpretation, and cleaning and sealing building materials. Links are provided throughout the slide show to documents and spreadsheets that provide more in-depth discussion of the studies.

Other research, studies and information

The California Department of Toxic Substances Control (DTSC) Emergency Response Program’s meth web page provides answers to common questions and links to other websites. The website was intended as a clearinghouse for available information on meth and former meth lab remediation.

California’s Office of Environmental Health Hazard Assessment provides public information on clandestine drug labs with technical support documents and fact sheets for the most common chemicals used in illegal meth production.

 

 

 

 

 

http://www.pca.state.mn.us/index.php/waste/waste-and-cleanup/cleanup/emergency-response/clandestine-methamphetamine-labs-and-wastes-in-minnesota.html

 

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