The employer must not allow a driver who refuses to submit to a required test to perform or continue to perform safety-sensitive functions. Refusing to submit to a required test covers a variety of situations, see the definition in . A refusal has the same consequences as failing a drug or alcohol test. See 49 CFR 382.211. Any driver holding a CPL or CDL is considered to have agreed to complete an alcohol or controlled substances test; see Controlled Substances and Alcohol Testing: Implied Consent (383.72).