The Boston Housing Authority (BHA) has gone smoke free.

Public housing residents across the city have received their final notice that as of Sept. 30, 2012, the authority’s nonsmoking policy became effective.

Boston is believed to be the largest city in the country with such a ban in place.

Last January, resident households began signing lease addendums agreeing that household members and guests will refrain from smoking in their apartments, anywhere in their buildings, and within a specified distance from the buildings.

The policy does not prohibit smokers from living in BHA-owned and managed properties. However, it does prohibit smoking in these buildings. A failure to comply will be a violation of a family’s public housing lease and may lead to a charge of up to $250 and actions to enforce the lease.