There’s a Catch-22 for local companies attempting to create a workplace free of substance abuse.

A surprising number of employees — and some key executives — are failing drug testing, according to one human resources expert.

“Companies who want to make a cultural statement as it relates to drug testing may mandate it for prospective and current employees,” said David Lewis, chief executive of Operations Inc., a human resources outsourcing and consulting firm.

“The challenge may come later, when these employers discover current workers — even top executives — fail the testing,” he said. In this scenario, companies may be forced to fire employees who test positive.

“Companies in New York have approached me for advice on mandatory drug tests for all their employees — and I tell them of the possible consequences. These tests do not always have very pleasant outcomes,” Lewis said.