Clandestine methamphetamine (meth) laboratories have been a growing problem throughout Colorado and across the United States. The number of meth lab seizures has increased dramatically over the past 3 years. In response to increased concerns over the contamination left behind at meth labs, the Department of Public Health and Environment has put together this guidance to assist in addressing contamination at former meth labs. This guide is not meant to modify or replace local requirements. Prior to beginning cleanup of a former meth lab, a preliminary assessment should be conducted to determine what chemicals are involved, the manufacturing method, and whether the property is fit or unfit for use as is. The removal of lab chemicals and equipment must be conducted by properly trained and equipped law enforcement and/or a hazardous materials cleanup team. Cleanup and sampling of former meth labs should be conducted under the supervision of a properly qualified person such as a Certified Industrial Hygienist. Decisions regarding the sampling plan can be made based on the preliminary assessment information, chemicals used and duration of lab operation, the apparent extent and severity of contamination, and professional judgement. After complete cleanup, small amounts of residual chemicals may remain. Post-cleanup sampling should be conducted after residual cleanup and/or the encapsulant has cured. There are difficulties related to testing and evaluating the concentrations of meth related chemicals in indoor air. The use of meth testing to evaluate the effectiveness of cleanup may be more practical than the use of indoor air concentrations of other associated chemicals. If areas of potential outdoor contamination are identified or suspected, further investigation of outdoor contamination may be necessary. 3 tables, 2 attachments, 12 references