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Adulteration: Description, Prevention and Testing

Adulteration: What is it ????

Cheating!! Someone attempts to alter the chemical composition of their urine specimen to "fool" the testing mechanism by adding a substance to the urine after voiding (in-vitro) or ingesting something prior to voiding (in-vivo) to disguise the drugs in their system. Another common practice is substitution; where a donor will substitute someone else's urine for his/her own.

In-Vitro Adulteration

When the urine is safely out of the body, people are more apt to add a chemical agent to the specimen. This is most commonly done when the actual collection is not being observed or when the collector fails to thoroughly check the body and belongings of the donor. Look for unnecessary bulges in pants pockets or under hats. Supply a secure box or place for the donor to leave "personal" items during the collection.

Some of the most common additives are water, bleach, salt, lemon vinegar, vitamin C and commercially sold products such as Urinaid, Klear, Urine Luck, etc. These cause adulteration of pH levels and specific gravity and for the most part can be detected with an adulteration panel at the laboratory.

In-Vivo Adulteration

Although drug culture mythology believes that swallowing any one of a group of compounds can produce a false-negative drug test result, this technique is not usually effective.

People have been known to swallow large quantities of fruit juice, pickle juice, salted coffee, herbal teas, golden seal root just to name a few. In truth, the kidneys have a buffering system that will naturally adjust the slight pH changes caused by acidic substances. On the other hand, drinking large quantities of these liquids or water may dilute (low Creatinine) the urine enough to create a negative drug test.


Most commonly done with improper observation of the collection, whereas, the donor will bring someone else's urine and put it in the specimen container. There have been reports of people being so desperate to pass their drug screen that they have catheterized themselves and refilled their bladder with someone else's clean urine.

Preventing adulteration

Vigilant collection staff can identify most adulterated and diluted samples provided that some common sense policies are built into the program. The following are some effective preventative measures:

  1. Don't announce random drug tests in advance.
  2. Secure the collection site to prevent tampering.
  3. No handbags, jackets, hats etc. allowed in the collection room.
  4. Require donor to wash his/her hands before giving the sample.
  5. Turn off or tape handles (especially hot water) to accessible faucets.
  6. Put a coloring agent in the commode. (Preferably blue)
  7. Inspect restroom for concealed adulterants. (Scouring powder, bowl cleaner soap, etc.)
  8. If pockets bulge, ask donor to empty them. If no questionable objects are found, objects may be returned to the pockets.
  9. Check temperature of specimen.
  10. Establish a "supervised" collection policy.

Detecting Internal Diluters

Dilution by drinking large amounts of fluid appears to be the most effective and arguably the most difficult form of adulteration to prove. The kidneys begin producing significantly dilute urine in only about 30 minutes following the ingestion of three or four 12 ounce glasses of water. The effect of this dilution is to increase the volume of urine and reduce the concentration of a drug in the sample.

However, while it appears that dilution is the most effective way to beat a drug test, it is not fair to assume that a person that gives a dilute sample is abusing drugs. Many people that have never abused drugs drink large amounts of fluids as a part of their daily routine.

Although a highly dilute sample by itself might not be reason enough to suspect drug use, in combination with other factors it very well might be. Testing for Creatinine can detect a dilute specimen or may be run as part of the adulteration testing panel.

Testing For Adulterants

(usually done as Creatinine only or full adulterant test)


Creatinine levels show the dilution of the specimen. Levels above 20ml/dl are acceptable and show that a specimen is good for testing. Specimens that show a creatinine level of less than 20 ml/dl are considered "dilute specimen" and unacceptable for testing.

pH level

This measures acidity in the urine and checks if chlorine bleach has been added to the specimen. The acceptable range is 4.0 (acidic) to 9.0 (base)


This portion of the adulterant test will check for oxidizing agents used in some drug test blocking products.

Specific Gravity

This checks to see if the urine has been watered down. The acceptable range for a specimen is 1.002 to 1.040.

** For testing purposes you may screen for creatinine or a full adulterant test **

Updated: April 14, 2010 — 4:41 am
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