On Monday, a new law took effect requiring paid sick leave for all San Francisco employees — even part-time and temporary workers. The sick leave ordinance is the first of its kind in the United States. It is sweeping in its scope, broadly protects employees and is demanding on employers.

The ordinance will have a dramatic impact on San Francisco’s workforce. Labor costs are estimated to increase by 3.3 percent for employers who currently do not provide paid sick leave or vacation days. The ordinance will have particular impact on restaurants and those who employ workers in labor-intensive, low-margin operations. And failure to comply will be costly.