For pre-employment testing, what amount of scalp hair is typically collected?

For pre-employment testing, what amount of scalp hair is typically collected?

• A. 100 mg
• B. 5 ml
• C. 30-45 ml
• D. 3 ml

Answer: (A)

In hair drug testing for pre-employment screening, a fixed amount of hair mass is collected to ensure there is enough material for all analyses and any necessary retesting. About 100 milligrams of scalp hair is typically collected, which provides ample material for a comprehensive panel and for confirming results if needed. This mass corresponds to roughly 50–100 hairs, depending on thickness, taken from near the scalp with a length of about 1.5 inches to capture drug use over the past couple of months. The other options are given in milliliters, which are volumes and not how hair samples are measured; hair samples are assessed by mass, making 100 milligrams the standard choice.

In hair drug testing for pre-employment screening, a fixed amount of hair mass is collected to ensure there is enough material for all analyses and any necessary retesting. About 100 milligrams of scalp hair is typically collected, which provides ample material for a comprehensive panel and for confirming results if needed. This mass corresponds to roughly 50–100 hairs, depending on thickness, taken from near the scalp with a length of about 1.5 inches to capture drug use over the past couple of months. The other options are given in milliliters, which are volumes and not how hair samples are measured; hair samples are assessed by mass, making 100 milligrams the standard choice.