Each house is different depending on the severity and frequency of the use or production. Some houses have been found to have in excess of 500ppm of meth – just from swabs on the walls. This may not sounds like much – but the ‘healthy’ limit is 1/100th of that.
Often the toxic gases not only contaminate the room in which the production occurred, but travel through air vents, heaters, and any other means of airborne transportation.
Significant contamination may require removal of some porous surfaces. This could include your furniture, curtains and other house hold items which may have been subject to secondary contamination even after the source of the meth is no longer in the property.