Temperature impacts both the donor providing the urine sample and the integrity of the urine sample while in transit to the lab.
Dilute specimens occur when the urine sample has a higher than average water content. There are several natural reasons a drug screen may be dilute, for instance, when a donor consumes increased fluids to avoid becoming dehydrated in the heat. Employers must decide whether a negative dilute specimen will result in requesting a new test for the donor, which a company's policy typically addresses.
Invalid results occur when a urine sample has a pH between 9-9.5. Prolonged and/or improper storage of urine or blood specimens may raise the pH of samples in transit to the lab for testing. Labs cannot reliably perform drug tests when the pH is outside of a certain range, culminating in an "invalid" result. Keep in mind that when samples are collected, they must be stored at room temperature - 18-25°C (64-77°F) - during shipping and storage conditions for at least one week to ensure accurate results. During the months of June through August, labs typically see an increase in invalid results due to these factors.
Being mindful of these conditions will help when determining next steps on the screening process and decisions to re-test candidates consistent with your company policy.
If you have any questions, please contact your sales executive, account manager, or our customer service team.
Posted: July 6, 2021