Winter warning: Businesses that use backup generators in case of power loss could end up falling under stricter pollution-control regulations.

Reason: State air pollution control officials are opposing a federal plan to let businesses operate stationary power generators that run for less than 100 hours a year without obtaining a Clean Air Act permit.

The feds proposed the 100-hour exemption for backup generators – when used during emergencies and for peak-hour generation – to encourage facilities to participate in various energy saving programs offered by utilities.

Create new health risk

But the National Association of Clean Air Agencies and the regional Northeast air agencies issued a report warning that the net effect of the exemption will be to increase air pollution, especially air toxic emissions, by encouraging wider use of diesel-powered generators.

The groups say the feds failed to properly evaluate the negative health effects caused by an increase in particulate, air toxins and other emissions created by burning diesel fuels.