Drug & Alcohol policy for contractors v employees No one should be under the influence of drugs or alcohol in the work place, meaning impaired as they could pose a risk to their selves and their work collogues. Cleaners handle chemicals, maintenance and repairs, hand and power tools, heavy lifting, driving vehicles etc. The usual would be random, post incident and pre-employment testing. You can have this requirement written into you contractor Pre-Qual. process. The form of testing is up to the Principle to decide, Urine and Oral Fluid can both be covered in your D&A Policy and then the process when you have a failed test.