NHA Certified Phlebotomy Technician (CPT)Collection RoutineHard
A phlebotomy technician is collecting a blood specimen for a blood alcohol content (BAC) test as part of a forensic investigation. Which of the following antiseptics should the technician use?
- AChlorhexidine gluconate
- BPovidone-iodine (Betadine)
- C70% Isopropyl alcohol
- DBenzalkonium chloride
Show answer & explanationAnswer & explanation
Correct answer: D. Benzalkonium chloride
For forensic blood alcohol content (BAC) testing, alcohol-based antiseptics (like isopropyl alcohol or chlorhexidine with alcohol) are contraindicated because they can falsely elevate the patient's BAC. Benzalkonium chloride is an acceptable non-alcohol antiseptic for this purpose.
Why the other options are wrong
- A. Chlorhexidine gluconate often comes with alcohol, making it unsuitable. Alcohol-free chlorhexidine is an option, but benzalkonium chloride is specifically mentioned as acceptable in many guidelines.
- B. Povidone-iodine is a suitable non-alcohol antiseptic, but it can stain the skin and some patients are allergic. Benzalkonium chloride is an alternative non-alcohol antiseptic.
- C. Isopropyl alcohol is an alcohol and would contaminate the specimen, leading to falsely elevated BAC.
Antiseptic for BAC Testing
When collecting blood for a forensic Blood Alcohol Content (BAC) test, an alcohol-free antiseptic such as benzalkonium chloride or povidone-iodine must be used to prevent contamination of the specimen.
- Alcohol-based antiseptics are contraindicated
- Prevents false elevation of BAC
- Benzalkonium chloride is a common non-alcohol choice
- Povidone-iodine is also acceptable if no allergies
Memory trick: No 'Alcohol' for 'Alcohol' tests – think 'Benz' for 'BAC'.