Understanding Blood Drug Testing in the Workplace

Although an employer cannot force an employee to take a blood test, refusing to take one when there is reasonable suspicion of being under the influence can lead to negative consequences for the employee. Employers must establish policies around alcohol and drug testing in the workplace so if an employee violates these policies, including refusing a test, it can be considered misconduct. 

Reasonable suspicion can be observing that an employee appears to be under the influence in that they are slurring their speech, have an unsteady gait or give off a strong smell of alcohol. (See our previous article, where we discussed collecting and recording evidence of an employee being under the influence.)  In this instance, with the correct policies in place, the employer can request a blood test. Refusal to submit to a blood test in these circumstances can lead to disciplinary action, including warnings or even dismissal, depending on the severity of the case. 

As mentioned in our article on 18 March 2025, drug testing is crucial to many industries. 

Blood drug testing is known for its precision, detecting the actual presence of drugs or metabolites in the bloodstream. It is often used in situations requiring exact drug concentration levels. 

How It’s Done 

A healthcare professional collects a blood sample, which is analysed in a laboratory to determine drug content and concentration. 

Accuracy and Cost 

Blood tests are the most accurate method for detecting recent drug use (within hours to 2 days). Costs range from R1 500.00 to R3 500.00, depending on the complexity of the analysis. 

Time for Results 

Results are typically available within 24–72 hours. 

Advantages in the Workplace 

• Provides precise drug concentration levels. 

• Suitable for post-incident investigations and high-risk roles. 

• Often used for forensic and legal purposes.

Relevant Legislation and Case Law 

• Occupational Health and Safety Act, 1993 (OHSA): Sections 8 and 14 support the use of blood testing to ensure a safe working environment.  

• Case Law: Minister of Justice and Constitutional Development v Prince (2018) underscores the importance of accurate testing methods for current impairment, making blood tests particularly relevant.