All breathalyzer tests or urine drug screens are conducted using certified testers and testing equipment. You are required to follow strict procedures for taking a drug or alcohol test and failure to do so could result in the test considered positive.
For urine tests, occasional false positives may occur. If you feel the test is false positive, the specimen can be sent out to a lab for definitive testing. This may be at your expense, depending on your company policy, but some employers will reimburse the cost if the second test is negative. If you are working in a safety sensitive position, you may be asked to “stand down” while confirmation proceeds.
Please be aware that marijuana is still illegal under federal law and positive tests must be reported as such, unless your company policy specifically excludes positive tests for marijuana. Drug tests are usually done for pre-placement, but some employers test “per cause” and some per any work-related accident. Please check with your Human Resources department for your company’s testing policies.