Drug Testing Tips

UK Drug Testing Tips  

We have put together this list of general drug testing tips to help you with your onsite drug screening

    1. Make sure you have everything that you need to perform the drug test before you start
    2. Read through the drug test kit instructions before you start and be sure you understand them.
    3. Familiarise yourself with the drug test kit that you are going to use. We have a series of training videos available on YouTube if you need them, for most drug & alcohol testing kits that we stock. If you need any help our customer support team are always available weekdays between 8.30 and 5pm.
    4. If you are performing an onsite drug test in a workplace setting and there is likely to be disciplinary action if the drug test result is positive, we recommend that you have at least one laboratory confirmation chain of custody drug test pack available on site, so that you can confirm the drug test result. We sell these online, and they can be ordered when you order your drug test kits.
    5. Informed consent is crucial. If you are doing the drug test on another person, for example in a workplace, then make sure that you have their consent. You can not perform a workplace drug test on an individual without their consent.
    6. Use a timer, as all onsite drug test kit results need to be read at a specified time. The time the results should be read varies from test to test. The timer on your phone is suitable.
    7. Keep good drug testing records. You can download our free to use editable procedure and records form (see below for more information on keeping drug test records)
    8. Don't forget about prescribed and over the counter medication-If you get a positive result on a drug test, check if the person you are drug testing has taken any medication in the 5 days before the drug test was performed. If you need any help or advice on cross-reactivity and if a consumed medication may influence a drug test result, then contact our customer services team
    9. Wear gloves if you are performing the drug test on another person in a workplace , school, prison or healthcare setting.  It is advisable to always wear disposable gloves to perform a urine or saliva drug test. These do not need to be sterile. A seeprate pair of gloves should be worn for each person being tested to avoid any cross contamination,  and the hands washed or sanitised in between. 
    10. PPE and Covid measures-During the pandemic we would also recommend that if you are performing the drug test in a workplace , school, prison or healthcare setting that it is done in a well ventilated room (open windows) or outdoors, and that you wear a face covering at all times, and or a visor, and that you socially distance. It is also advisable that the person being tested also follows precautions like social distancing and mask wearing, and only removes their mask to perform a saliva drug test.

Always keep good drug screening records

Saliva Drug Test Tips

All the general tips above apply to saliva drug testing. Here are some additional ones that are specific to oral fluid drug testing.

  1. Know and understand the exact drug test kit that you are using. It is very important to familiarise yourself with the individual oral drug test kit that you are using, as saliva drug testing kits do vary considerably in design.
  2. There must be saliva in the mouth. You must wait at least 20 minutes since the person has eaten or drunk anything before performing a saliva drug test.
  3. Enough saliva is essential for the test to work. It is therefore vital to collect an adequate saliva sample to thoroughly wet all elements of the drug test membrane. Inadequate saliva sample is the most common reason for an invalid saliva drug test result.
  4. Saturate the sponge collector with saliva. The oral fluid collection swab should be wiped all around the oral cavity and mouth including under the tongue and inside of the cheeks before it is saturated with saliva. Ask the person being drug tested to feed saliva onto the collector.
  5. The higher than number of drugs being tested for the more saliva is required to run the drug test. A 12 in 1 or 13 in 1 saliva drug test kit will require more saliva to run the tests than a 6 in 1 oral drug test kit. If you are new to saliva drug testing, it may be wise to start with a 6 panel saliva drug test kit rather than a 12 panel saliva drug test, until you are confident in the procedure of collecting the saliva sample.
  6. What to do if an not enough saliva sample is collected. If the saliva sample is inadequate only part of the test membranes will run. Try putting it back in the mouth and collecting more saliva. If this does not work you may need to run another test.
  7. If the oral fluid test kit does not run fully the most likely reason is inadequate saliva sample collection. The collection device needs to be really wet with saliva. 
  8. If you think that your saliva drug test kit may be faulty then add some water to the test. If the test then runs the problem was inadequate saliva sample, not the drug test kit
  9. It is advisable to always wear disposable gloves to perform a saliva drug tests. The gloves do not need to be sterile but a new pair of gloves should be worn for each test to avoid any risk of cross contamination.

See our full range of saliva oral fluid drug test kits

Urine Drug Testing Tips

All the general tips above apply to urine drug testing. Here are some additional ones that are specific to urine drug testing.

  1. Be prepared and make sure you understand and are familiar with the urine drug test kit that you will be using. The drug test kit designs do vary, and if the urine drug test is not integrated into a urine cup you will need to have a collection cup of some sort to do the drug test.  It is therefore crucially important to familiarise yourself with the individual urine drug test kit that you are using, and make sure that you have everything you need to perform the urine drug test.
  2. Do you need a collection cup-If you are using a multi-panel urine drug test kit or a urine drug test strip, you will also require a separate urine collection cup, that you dip the drug test panel or test strip into. If you are using an integrated cup urine drug test kit, the drug test panel is built into the collection cup, so you do not need a seperate sample pot. These integrated cup drug test kits are very popular for workplace drug testing for this reason.
  3. Fresh urine sample is preferable. It is best to perform the urine drug test on a freshly produced urine sample, so that you can be confident that the urine sample is from the individual that you are drug testing, and that they have not substituted someone else's urine sample for their own.
  4. Ask yourself could the sample have been diluted or tampered with in any way. Be aware that some individuals being drug tested may try to add water from the toilet to the urine test to dilute it. It is worth adding a coloured toilet block to the cistern of the toilet that you are using, to prevent this.
  5. The urine sample should be at body temperature if it fresh. Some integrated urine drug test cups have a built-in temperature strip so that you can check it is at body temperature. 
  6. Urine adulteration test strips are available so that you can check if the urine sample has been adulterated or diluted in any way. Some cup drug testing kits now have an adulteration test strip built in. 
  7. Wear disposable gloves. It is advisable to always wear disposable gloves to perform a urine drug test, to avoid coming in to contact with urine.
  8. Multi-panel urine drug test kits are by far the cheapest option when you need to test for multiple drugs on one urine sample, but they do require an additional collection cup. If you only wish to test for one drug then drug testing strips are your cheapest and best option. They are just as accurate as the more expensive drug tests.
  9. Remember to remove the cap or cover from the drug test when using a panel drug test. Once you remove the cover the prongs will be visible and they are what you dip into the urine sample. If you forget to remove the cover then the drug test is unable to absorb any urine, and you will get an invalid result . You would be amazed by how many invalid results, are caused by the person performing a drug test with a panel drug test kit, forgetting to remove the cap or cover to expose the prongs, before dipping the test kit prongs in the urine sample.
  10. Remember on some urine panel drug testing kits the results will appear on both sides of the drug test panel. If you are using a 6, 7, 10 or 12-panel multi-panel drug test make sure you read the results on both sides of the drug test kit. You would be surprised how often people forget to do this.
  11. Integrated cup drug test kits are the best option for workplace urine drug testing as they screen for multiple drugs, and are the easiest format of urine drug test kit to use as the drug test is built into the sample pot.
  12. Confirming a non negative drug test result  If you need to confirm any non negative drug test results, for example in a workplace setting where disciplinary action may be taken on the basis of the drug test results, then it is advisable to have a laboratory drug test confirmation pack ready so that you can send your sample straight off to the lab without delay.


Tips For Interpreting Drug Test Results

  • Always read the the drug test result at the correct time (use a timer)
  • Do not go back to a drug test kit and read a result after 10 minutes
  • A negative result on a drug test kit ( ie no drug detected) is when you get a visible Control line (C) and a visible Test line (T)
  • A positive result on a drug test kit is when you just get a Control line (C) but no Test line (T)
  • The two lines on a drug test kit do not need to be of the same intensity
  • A faint T line on a drug test is still a negative result
  • The strength of colour of the T line on a drug test is not of any significance. You may find this UK Drug Testing blog post useful 'What does a faint line on a drug test mean?'


Drug test sensitivities and detection times information

Drug testing tips page last reviewed and updated by Dr Kate Garside 27/4/22 

Collapsible content