A little more than six years ago, my American husband received a job offer in Switzerland. I was working as a labor and employment law consultant in the United States, and I asked him, "How are they doing the drug test? Do they contract with someone local? Does the U.S. office of the company take care of it?"

He looked through the paperwork and contract (Swiss jobs come with contracts), and said, "There's no drug-test information."

I knew this had to be a mistake. His job was for a pharmaceutical company. I worked in HR for a pharmaceutical company and knew full well that every one of our competitors did drug testing. I urged him to call the hiring company and get it straightened out right away--after all, we didn't want to move the whole family across the ocean only to be told, "Oops, we forgot to do the drug test. You can't start until we get the results back." He held firm. "This is Switzerland," he said. "The Swiss don't make mistakes."

It turns out that they don't test for drugs regularly either. And while marijuana usage and possession is illegal there, the consequence is a fine of 100 Swiss francs (currently, $104), and nobody seems to care all that much.

A Swiss HR manager informed me that drug testing is done only when safety is a consideration--as for an airplane pilot. Otherwise, drug and alcohol use at work is not allowed, but who cares what you do on the weekend? Testing employees, the federal data privacy commission ruled in 2003, is a violation of their privacy.

The lesson for your business: If the Swiss can be super productive and have an awesome economy without doing routine drug testing on salespeople and accountants, is there any reason why you're spending the money to drug-test your employees? Remember, safety is different from tradition.

Darren Dupriest, president and CEO of Validity Screening Solutions, a U.S. company that handles background checks, including drug testing, for global companies, says marijuana testing at work is becoming very complex. With recreational usage being legal in a few states and gaining ground in more, companies with a presence in more than one state can find themselves confused. And more so, what about companies with a global presence?

U.S. businesses are naive, Dupriest says, to think that everything is the same everywhere you go. When you suspect an employee of being under the influence of marijuana in the United States, he says, you can get a rapid drug test. The same test in India may take a week or more.

The lesson for your business: Don't make assumptions that your business policies will easily transfer to the new country. Even if what you want to do is justified, it may not be practical. Do you really want to suspend someone for a week while you wait for drug test results to come back? Can you even get an appointment in a timely fashion? Make sure that things make sense where your employees are, not just where you sit.

What do you do when your employees work overseas or even go on a short business trip, to say, Holland, where marijuana usage is legal? A Dutch acquaintance of mine, who wishes to remain anonymous, shared a story with me. A friend of his got caught at work, as a truck driver, with marijuana. While smoking is fine, doing so while driving a truck is not. The company fired him. He fought the termination, because the company hadn't proved that he smoked while on the job. Mere possession while at work isn't enough evidence to fire someone.

The lesson for your business: In the U.S., an employee's possessing marijuana at work would be cause to fire that employee--no HR person would object. It's not the same everywhere. Make sure that you don't react as you would at home to a problem abroad.

But, what do you do when your star performer, who was happily living in Portugal or Uruguay, where marijuana usage is legal, gets transferred to the United States? This person has been performing at a high level and you've never drug-tested him. But, your U.S. policy is drug testing for everyone, and before he can go on U.S. payroll, he needs clean test results, right? When he fails, what do you do? Does something that didn't matter yesterday suddenly matter today?

The lesson for your business: Think through exactly what your policies mean. Remember that even the FBI changed has changed its lookback period for marijuana usage because it couldn't find enough people who qualified. Do you really want a policy that is going to damage your ability to hire the right people?

HR manager Nivedita Bhagnari worked for a company that had offices across Northern Africa and the Middle East. They tested for drug usage for all jobs--even ones that were not safety related. Interestingly, she says that it was the older employees that had a problem with it: "The Millennials understood the importance of these tests and how it protects them in a workplace to have a drug-free work environment. However, the Baby Boomers had a mixed reaction. Some of them supported it and some of it did not."

The lesson for your business: Don't assume that all Millennials want one thing and all Baby Boomers want another. Culture is going to matter in implementing policies and it's not just a culture by age. As you go global, different populations will react differently to your policies. Think before you implement.

The Middle East has a very different approach to marijuana usage than does Europe. In the United Arab Emirates, even a tiny amount of illegal substance can land you in a four-year prison term. Better than Malaysia where 7 ounces of marijuana can get you the death penalty.

The lesson for your business: Before you send your employees on so much as a business trip abroad, you need to be certain they know what to expect and what the consequences will be when they return. Make sure that you are clear as to whether they are expected to live by U.S. standards or should follow local law. Understand that in some Middle Eastern countries, having drugs in your system is evidence of possession. This means that, if your company is located in a place where marijuana is legal, those employees who use before they relocate could land in jail for something they did before they arrived in the country where it is illegal. On the other hand, If you're going to fire people for smoking marijuana while in Holland, tell them before they get on the plane.

Do your current policies make sense? Or are you just acting, as Dupriest said to me, according to the "Just Say No" campaign of the 1980s? Make sure you're in line with all applicable laws, whether at home or abroad, and then make sure your policies match your business needs and goals.