Why do I need a saliva test?

If you have been drinking heavily the night before it would be useful to know whether you are over the limit the following morning. Especially if your job involves the ability to drive or concentrate. The blood alcohol concentration (BAC) at which an individual becomes impaired is variable depending on the individual, such as size, weight, metabolic rates, eating habits and alcohol tolerance will play a part in the results a saliva test strip will give.

To read more about the effects of alcohol on you liver click here.

How accurate is this test?

It is well established that the concentration of alcohol in saliva is comparable to that of blood. The relationship between the amount of saliva alcohol and blood alcohol is 1:1 while with breath it is .000048:1, making saliva a more sensitive testing medium than breath.

Test procedure

Nothing should be placed into the mouth for at least 10 minutes prior to saliva collection. This includes food, drink, tobacco products or other materials. The saliva specimen can be collected in a cup or a clean container, or directly applied to the reaction pad of the test strip.

1. Open the foil package and remove the test strip.
2. Saturate the reactive pad by dipping the reaction pad into the saliva specimen collected in a sputum cup, or by applying saliva directly to the reaction pad. After 10 seconds, shake off the excess saliva.
3. Immediately start timer and at 2 minutes, compare the reactive pad with the provided coloured chart.
4. Results after more than 2 minutes may be not accurate

It is possible to detect the presence of alcohol in other fluids, such as drinks. However, if used in this manner the colour chart on the outside of the package does not apply. If alcohol is present in the fluid a colour change ranging from a yellow/light blue/dark blue/black will occur as the alcohol concentration increases. Little or no colour change may occur with pure alcohol due to the absence of water, which is required for the colour change reaction.

Results

Negative: Almost no colour change by comparing with the background. The negative result indicates that the BAC is less than 0.02%.
Positive: A distinct colour developed all over the pad. The positive result indicates that the BAC is 0.02% or higher.
Invalid: The test should be considered invalid If only the edge of the reactive pad turned colour that might be ascribed to insufficient sampling. The subject should be re-tested.

This test ranges from zero alcohol present to the legal driving limit and above. The legal limit at the current time in the UK is 80milligrams of alcohol per 100millitres of blood. This is marked as 0.08% on the packet.

Test limitations

This alcohol test could provide inaccurate results if the instructions are not carried out properly. Please remember the following:

• Failure to wait 15 minutes after placing food, drink or other materials in the mouth before running the test can provide inaccurate results due to possible contamination of the saliva by interfering substances.
• If you wait longer than 2 minutes before reading the result.
• Rapid Alcohol Test is designed for use with human saliva only. A positive result indicates only the presence of alcohol and does not indicate or measure intoxication. There is a possibility that technical or procedure error as well other substances in certain foods and medicines may interfere with the test and cause false results.
• Never use the test past the expiry date on the outer packet.

Storage

This test should be stored at room temperature.

For full instructions on how to use these tests click here.