The American Civil Liberties Union has taken up the case of a former employee of Morton Thiokol Inc. who was denied unemployment benefits after being fired for failing a drug test.

A brief was filed by the ACLU on Wednesday with the state Court of Appeals seeking restoration of the unemployment benefits denied to Kevin R. Johnson of Roy.Johnson was fired after testing positive twice for marijuana. The first test was administered by Morton Thiokol after Johnson was involved in an accident with a company vehicle in September 1987.

Attorney George Haley, who is handling the ACLU case, said the amount of marijuana measured by the test was enough by Morton Thiokol's standards to require future random testing, according to the company's policy.

A second, random drug test 65 days later found a much smaller amount of marijuana, Haley said, but still enough by the company's standards to fire Johnson. When Johnson was granted unemployment benefits, Morton Thiokol successfully challenged the decision to an administrative review board.

Review board members rejected Johnson's claim that he had stopped smoking marijuana after the accident. Johnson testified that the marijuana detected in the second test came from his roommate's smoking the drug.

The denial of benefits is unconstitutional, said Haley, because the board ruled that merely associating with someone using illegal drugs was sufficient grounds to withhold payment.

"That's what we take real exception to," Haley said. The law says unemployment benefits cannot be denied except in cases of job-related misconduct, he said.

He said that although someone might be fired for engaging in after-hours activities considered unbecoming conduct for an employee, he would not then be denied benefits since the activities would not have been job-related.