A drug test of a prospective or existing employee, other than a prospective or existing exempted employee, that yields a positive result solely for 11-nor-9-carboxy-delta-9-tetrahydrocannabinol, shall not form the sole basis for refusal to employ or to continue to employ or otherwise penalize such prospective or existing employee, unless (1) failing to do so would put the employer in violation of a federal contract or cause it to lose federal funding, (2) the employer reasonably suspects an employee’s usage of cannabis while engaged in the performance of the employee’s work responsibilities, (3) the employee manifests specific, articulable symptoms of drug impairment while working that decrease or lessen the employee’s performance of the duties or tasks of the employee’s job position, including, but not limited to, (A) symptoms of the employee’s speech, physical dexterity, agility, coordination, demeanor, irrational or unusual behavior or negligence or carelessness in operating equipment of machinery, (B) disregard for the safety of the employee or others, or involvement in any accident that results in serious damage to equipment or property, (C) disruption of a production or manufacturing process, or (D) carelessness that results in any injury to the employee or others, or (4) except as provided in section 21a-408p, such drug test was pursuant to a random drug testing policy pursuant to subdivision (1) of subsection (b) of section 21a-422p or was of a prospective employee with a conditional job offer, and such employer has established in such policy that a positive drug test for 11-nor-9-carboxy-delta-9-tetrahydrocannabinol may result in an adverse employment action.