(Bloomberg) – Legalized marijuana has left apartmentlandlords in a haze (of confusion).

In recent years, tenant demand for smoke-free livingenvironments has led property managers to extend bans oncigarette smoking to cover marijuana. But somelandlords worry that forbidding the use of medicalmarijuana might put them on the wrong side of fair housing law.

The uncertainty derives from a tension between statelaws legalizing marijuana and federal rules that outlaw thesubstance. A 2011 memo from the U.S.Department of Housing and Urban Development instructed localhousing authorities to reject medical marijuana users applying forfederally subsidized housing, because federal law definesmarijuana as a Schedule I drug. But state laws intended toprevent landlords from discriminating against renters on thebasis of a disability could offer tenants a greater measure ofprotection.

“You could have a tenant say, 'It's a violation for you to evenask me about it,'” said Morgan Stewart, a partner at law firmManly, Stewart & Finaldi in Irvine, Calif. “Maybe thelandlord's response is, 'We operate pursuant to federal law.''Well, OK, but I'm a California tenant.' Landlords are stuck in themiddle.”

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In May, the California state Assembly passed a bill that giveslandlords explicit permission to ban marijuana smoking, even formedical use. The state Senate has yet to vote on the bill, whichfollows a state law passed in 2014 that spelled out the right oflandlords to ban tobacco smoking on their properties.

Property owners are increasingly making apartment complexessmoke-free to appeal to tenants who see smoke as a health risk or anuisance, said Tom Bannon, chief executive of the CaliforniaApartment Association, a landlord group that supports the law.Smoke in an apartment also increases the likelihood that thelandlord will have to spend money on new carpeting or fresh paintwhen a tenant moves out.

“We believe what goes on in someone's unit, that's theiropportunity to do what they want, as long as they don't infringe onother people's rights,” Bannon said. “This doesn't stop them fromother uses. There are things like edibles, or oils, orwhatever.”

The consequences of the California law depend on the details andwhether it's actually enforced, said Chris Lindsey, seniorlegislative analyst at the Marijuana Policy Project, apro-legalization group. (One sticky point for Lindsey: whethervaporizing devices are included in a smoking ban.) To some degree,landlords already have the ability to undermine legalizationefforts, which have helped pass some form of marijuana use in 24states and the District of Columbia.

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“Even in legalization states, you can't smoke in public, theydon't allow the marijuana equivalent of a bar, and now [your]landlord says you can't smoke at home either,” Lindsey said. “Youcan end up in a situation where it's legal, but you can't smokeanywhere.”

For decades, pot was illegal, which didn't prevent people fromshoving a towel under their door and smoking in their rentalapartments. Legalization may be leading landlords to ban smokingand hand out brownie recipes, but smoke-free policies won'tnecessarily stop people from lighting up, said Bret Sachter, anattorney in Seattle, where recreational marijuana use is legalunder Washington state law: “I never knew of someone being evictedfor marijuana use when it wasn't legal, and I haven't seenlandlords updating their leases now that it is.”

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