Class Activities

“You Be The Judge”


  1. To demonstrate understanding of drug analysis using hair and urinalysis
  2. To explore the ethics of drug testing and its implications
  3. To understanding binding (chemical bonds) and binding sites

For many employers today, job applicants must undergo drug testing. One company’s drug policy states that all applicants must be drug free for at least 6 months prior to application. Applicants will be subjected to hair sample and urine analysis tests.

Based on what you have learned about how drugs enter and exit the body and how drugs bind to the melanin in hair, study each applicant’s profile and identify applicants who could be proven ineligible for employment. Each group should discuss the facts and prepare answers to the four questions listed below.

Hair grows approximately 1 cm / month
Metabolites found in hair denote drug use at that time.
Overall binding to the entire hair shaft denotes secondary exposure.
Eating poppy seeds may give a false positive result because they contain trace amounts of opiates that can be detected in a urinalysis.


a) White male, 30, alopecia (no hair at all), eats poppy seed muffins almost every day.

b) Asian male, 24, black hair, 3 cm long, overall binding of entire hair shaft.

c) Black male, 27, shaved head, eats poppy seed bagels every day.

d) Hispanic female, 22, auburn hair, 40 cm long, metabolites found 3 cm from root.

e) White female, 36, dark brown hair, 36 cm long, metabolites found last 20 cm of hair.

f) White female, 37, prematurely fully gray hair, 22 cm long. Negative urine test.

g) Black female, 31, albino, hair 28 cm long, eats poppy seed muffins everyday.

h) White male, 29, blond hair 30 cm long. Smokes cigarettes.

1. Who (if any) were proven drug users during the past 6 months?

2. What should policy makers know about these tests’ results in order to make fair interpretations?

3. What are the ethical implications of mandatory drug testing?

4. If you were the employer making the hiring decisions would you eliminate anyone else on this list? (If so, is it legal for you do so?)

Teacher Notes:
Make available copies of pages 6-11 from the teacher guide for each group. Each group should answer each of the four questions above and be prepared to defend their conclusions in a class discussion.

The assessment item may be used as a group assessment or individual. The truth table application may be used for those students who have difficulty keeping track of several facts at one time. The truth table can be found by going to the Downloads section on the menu above and selecting the file for Module 2, or by clicking here.

Consider the following information and re-examine your applicant list and determine if you would eliminate any additional persons from your hiring list. For each individual, A-H, write a statement of available for hire or not to hire and give reasons for those not to be hired based on drug usage.

The positive test for opiates after eating poppy seeds should last about 3-5 days. The applicant could be asked to avoid eating poppy seeds and return in five days for re-testing.

Hair for drug testing is usually taken from the head but can be taken from any part of the body.

Additional results:
A, C, E were re-tested. A and C were negative urinalysis and G tested positive.