What is known:
3. Cross Contamination
What is known regarding Clandestine Methamphetamine Laboratories:
- Based on sampling conducted by National Jewish Medical and Research Center and others at actual clandestine laboratories and controlled methamphetamine cooks, we know that a wide variety of solvents, acids, bases, iodine, phosphorous, phosphine, anhydrous ammonia, methamphetamine and other compounds may be present at a clandestine methamphetamine laboratory. (1-11)
- The compounds that will be present will depend upon the method of manufacture utilized, the temperatures at which the cook is conducted, and the idiosyncrasies of the individual conducting the cook. The compounds and amounts will also depend upon the incidence of accidents, fires and spills, and will likely be higher during active cooks. (1)
- The most common compounds found 24 hours after a staged red phosphorous "cook" were iodine, hydrogen chloride, and methamphetamine. (5) It is believed that these are the primary compounds present after most cooks. In the case of methamphetamine labs utilizing the phenyl-2-propanone method of manufacture, mercury and lead may also be common contaminants. However, the P-2-P methodology is not a common production method at this time. Solvents may also be present but will generally be in relatively low concentrations within 24 hours of the last "cook".
- Individuals and items associated with the clandestine manufacture of methamphetamine or the area in which the "cook" was conducted may have residual surface levels of at least some of these compounds present (i.e. on clothes and skin). The magnitude of these residual levels will depend upon their proximity to the cook area, the type of cook, the temperature of the cook, the amount of the cook, ventilation systems utilized, etc. (1,2,3,4)
- Generally speaking, residual chemical levels will be highest on the individual conducting the methamphetamine manufacturing process and lowest on an individual that was not present during the cook and just entered the structure for a short period of time. Demonstrated methamphetamine levels range from no methamphetamine detected to as high as 580 µg per wipe on a cook's hands. Exterior levels of methamphetamine found on the protective equipment of individuals after a single cook are generally less than 50 µg /wipe (approximately 100 cm2). Expected levels of residual chemicals, other than methamphetamine, are not known at this time. (1,4)
- After a staged clandestine methamphetamine manufacturing process, residual levels of methamphetamine were present on most surfaces near the area in which the cook was conducted, and most individuals entering this area did pick up some methamphetamine on their outer clothes and skin. After a single cook, the residual level found on clothing will depend on many factors but generally is found to be less than 20 µg /wipe. Multiple cooks may result in higher contamination levels. In addition, high activity levels (cleaning, crawling on the floor, etc) or direct contact with the chemicals may also result in higher residual levels on clothing, skin, etc. (1,4)
- At this time, there is no known existing methodology by which to reliably determine the residual levels of these chemicals on a real-time basis. Photo ionization devices, organic vapor meters, explosion meters, ion mobility spectrometers, and immunochemistry devices all appear to have limitations that make them unreliable for determining relevant residual chemical levels on individuals or surfaces.
- The effectiveness of wipes to decontaminate large surfaces or semi-porous items has not been documented. In addition, wipes are totally ineffective in removing chemical residuals from porous surfaces. Research suggests that wipes are more likely to spread chemical residuals than to remove these residuals from skin. In fact, new research by the State of California suggests that the use of wipes may result in a faster uptake through the skin of contaminated individuals. Warm soap and running water has been found to be much more effective in removing methamphetamine contamination and is the preferred method of chemical removal.
What is Known Regarding Contamination after the Use of Methamphetamine:
- Methamphetamine may be used in a number of ways within a structure. It may be ingested, injected, and aerosolized (smoked). All of these methods of use result in chemical contamination within a structure due to spillage, use of chemicals, and aerosolization of the methamphetamine. Aerosolization (smoking) of methamphetamine may result in the most widespread contamination of the drug itself since the temperature at which methamphetamine becomes an aerosol is lower that the temperature at which it burns. The primary contaminant, therefore, will normally be the drug, methamphetamine.
- A simulated "smoking" of methamphetamine in an hotel room resulted in contamination on the walls and floors within the room that ranged from a mean 0.23 µg /100 cm2 to a high of 15.44 µg /100 cm2 of methamphetamine depending upon how much "smoking" had occurred. It is estimated that actual "smoking" may result in slightly lower levels of methamphetamine ( a mean of 1.5—5.1 µg /100 cm2) due to uptake by the individuals doing the "smoking".
- The levels of methamphetamine left behind due to the "smoking" of methamphetamine may exceed the levels currently proposed as a health based standard for children (1.5 g / 100 cm2). These levels will be much lower than the methamphetamine levels commonly associated with the clandestine production of methamphetamine.
What is Known Regarding Cross-Contamination and Decontamination from Methamphetamine-Contaminated Environments:
- A total of 83 samples were obtained from law enforcement officers, firefighters, suspects, and a pet involved with suspected methamphetamine laboratories. Seventy-two of the 83 individuals (87%) tested positive for methamphetamine. The mean contamination level was 8.7 µg/sample with a median contamination level of 0.97 µg/sample. The lowest contamination level observed was 0.05 µg/sample and the highest level was 230 µg/sample. In general, the observed contamination level for individuals simply entering a laboratory were relatively low.
- A total of 18 samples were taken from individuals and a pet at three suspected methamphetamine laboratories. All but one of the samples were positive for methamphetamine (94%) with a mean contamination level of 5.5 µg/sample and a median level of 3.22 µg/sample. The highest contamination observed was 17.4 µg/sample obtained from the hands of a suspect involved with a suspected clandestine laboratory investigation.
- Samples were obtained from individuals at a simulated cook 24 hours after the cook. A total of 64 samples were collected with 54 of the samples indicating some contamination (84%). The mean level of contamination was 9.8 µg/sample with the median contamination level of 0.66 µg/sample.
- Firefighters entering a simulated "cook" residence under three scenarios had varied levels of contamination. The lowest contamination involved the firefighters simply entering the house and walking around. The medium contamination scenario included moving items and moving throughout the house. The third scenario involved significant movement, horseplay, and vacuuming in the house. The data shows a general increase in the contamination levels depending upon the activity level. Mean contamination levels ranged from 0.6 µg/sample for low contamination to a mean of 11 µg/sample for individuals involved in more active activities. The highest contamination levels were observed on the feet where contact with the carpeting occurred.
- Based on this information, it is likely that the contamination level on clothing after entering an inactive laboratory or a structure where methamphetamine has been used will be relatively low. The primary contamination will be on the feet and hands but other areas of the body may also be contaminated.
- It is expected, based on research conducted on pesticides, that transfer rates of chemicals from the surface of an individual or item associated with a methamphetamine lab to the surface of a person not associated with a lab may be as low as 10%. It has been demonstrated in the field that simply handling individuals associated with a methamphetamine laboratory may result in the transfer of very low but detectable amounts of methamphetamine. We predict, however, that even if some methamphetamine is transferred, only a small proportion will be absorbed into the body of another person coming into contact with the child.
- It has been shown that methamphetamine on the surface of wetted skin will result in a rapid uptake into the body of the individual. Concentration, pH, and moisture are the primary determinants as to how much and how fast the methamphetamine will enter the body.
- In experiments where clothing items contaminated with high levels of methamphetamine were washed in warm water with a simple detergent, over 99% of the methamphetamine was removed after only one wash. Continued washing brought contamination levels down even further. It is unlikely that clothing washed in a washing machine using detergent and warm water will present a hazard to individuals exposed to that clothing.