Hiding condoms containing clean urine on the body or inside the vagina is one common method. Tubes may also be inserted into the urethra. People will add bleach, liquid soap and many other household products in attempts to mask drug use. One technique is to hide a masking substance under the fingernails. Another method is to poke a small hole into the container with a pin so that the sample leaks out by the time it reaches the lab.
Many labs routinely test for contaminants because of adulteration.
Urinalysis cannot measure impairment or other behavioural effects of drugs. . Drug testing programmes are very expensive. Urinalysis cannot determine precisely when the drug was used nor can it identify the quantity of the drug ingested. To be even reasonably sure of continuing drug free status, frequent re-testing would be needed this is very intrusive and very expensive. Drug testing is extremely intrusive of the right to privacy.