Comparison of the different types of on-site drug testing devices
The market is flooded with different types of drug testing devices such as those which uses saliva, urine, hair, sweat and blood. The most common types used for on-site testing are those that are termed as non-invasive as with sweat, urine and saliva. They can offer results in less than 10 minutes making them ideal for application in screening of employees and such. They are under the “Waived Category” of tests according to the SAMHSA categorization standards that define them as the easiest to use with out the need for specialized personnel or training. These tests usually work on the detection of the most basic “Golden 5” or those drugs classified and grouped under the NIDA-5 but may not be limited to them. There are tests that can detect 10 substances that are now categorized as part of the drug abuse problems that were not included in the primary 5 group.
Most urine testing systems use either cup style or specimen acquisition with some products having their testing strips built-into them to prevent adulteration which becomes a key issue in the non-invasiveness of the test. Though no painful injections are used in the acquisition, there are many cases where the samples obtained have either been diluted or mixed with water and other chemicals that are widely available on the market today rendering them useless. Most organizations that use the stated form of testing either have their acquisition process done with observers who accompany the test subjects thereby violating privacy of the said individuals. Having observers cannot also be called a fool-proof method of safeguarding the specimen for testing for the many factors that can differ from individual to individual. Urine tests are fast, and easy to administer that follow the principle of visual detection of competitive binding immunoassay method for screening without the need for instrumentation. This method employs a unique mixture of antibodies that selectively identify the drugs of abuse and their metabolites in test samples with high degree of accuracy. In the assay process, urine mixes with labeled antibody-dye conjugates and migrates along a porous membrane. If the concentration does not exceed the limits set by the SAMHSA and DHHA it shows as bands of lines along pre-marked areas of the test strip which shows that there was enough antigens present and that all of the specified or required chemicals or metabolites have been tested and shown to be within the limits. If they are at or above the said limits, they would show up on a different area with respective bands along with the control bands and give a positive result. The only down side is that urine is categorized as human waste and thus a biological hazard that requires disposal in manners that are dictated in dealing with such infectious waste. Most body fluids are capable of containing bacteria or viruses that can survive long after it leaves the body and requires special handling when it comes to disposal of the used test kits.
Saliva testing requires the subject to place a porous membrane into the mouth where saliva goes through to a testing strips that work similar to urine testing that works through the immunoassay method where the specific antigens are tested and compared to control strips that would indicate either the presence in limits exceeding pre-set standards of NIDA-5 category testing. This type of test is categorized to be the most non-invasive and biased of all drug screening processes due to the fact that, the test subject can be present as the test results are collected and interpreted. There is also less room for adulteration which could invalidate the test as with urine testing where additives or adulterates are added to fool the testing device or appliance. The test device is also rather smaller making disposal simpler than having to deal with a lot of infectious waste. But it is always a good idea to treat these testing-by products as infectious for they can harbor and transmit disease and viruses. So proper care and disposal in handling is required in compliance with DHHA approved methods and disposal
Sweat drug screening employs similar methods and vary only in the collection media and specimen collected. A sweat patch is usually attached to absorb and provide the adequate quantity of sweat the body produces. It also uses immunoassay approach to determine the presence of drugs commonly attributed to abuse.
The rest require laboratory examination as with blood and hair samples where they are collected and stored in special containers. These samples are also accompanied by a chain of custody document that is required by law to be accomplished by each and every individual from the sample collection technician, transport and testing. This ensures highly accurate results which could not be assessed by simple on-site testing.
On-site screening is preferred due to several factors like time, if a company was to conduct testing through accredited laboratories employees would have to leave the company premises for testing. This would result in non-productive time that is used up for the testing process which on-site testing hopes to eliminate. Other constraints such as the cost of transport, for the employer has to pay for transportation for their employees and when quite a number of employees require testing, production is affected which most companies don’t like.
Being in kit forms, the most basic drug screening products cost less than $20.00 compared to laboratory fees that have to be paid not to mention the cost of sending samples to these accredited labs for processing and interpretation. The samples are also less prone to degrading due to immediate results as compared to blood samples that have to be stored at a specific temperature and validity of samples is limited to a number of hours. Urine samples when transported are also subject to conditions and time constraints that have to be satisfied to allow valid tests to be carried out on them.
Portable testing kits cannot offer the degree of accuracy testing that is performed in accredited Laboratories but does offer an easy and affordable way of enforcing and implementation of a drug free environment. These test kits can be defeated through many means that would render them useless but newer versions include adulteration detectors that can tell if the sample being tested has either been diluted or modified. In cases where these suspicious results are detected, a more detailed analysis through hair or blood sampling can be used to provide a more detailed examination in the lab away from the hands of those who aim to defeat these portable testing methods.