The City of Ottawa has banned fluorescent light bulbs from regular garbage, after handing out thousands of the bulbs to city residents as part of a greening campaign.

Bay Ward Coun. Alex Cullen recently noticed the label on the energy-efficient light bulbs said they contained mercury, a toxic heavy metal that can damage the human nervous system.

Under Project Porchlight, the city and Hydro Ottawa have distributed 25,000 compact fluorescent light bulbs to residents of Ottawa South in a campaign to encourage energy efficiency.

City officials say each bulb contains five milligrams of the element. In comparison, they note that the average metal tooth filling has 500 milligrams of mercury and a watch battery has 50 milligrams.

Organizers say the bulbs are safe to use, and no mercury is emitted while using the bulb. Many types of lights contain mercury, including fluorescent and neon lights.

Cullen complained to the city that the bulbs should not be thrown out with the curbside trash, arguing they could break in landfills, allowing the mercury to leach into the water and create a public health hazard.

A planning and environment committee decided Tuesday that the city would treat the bulbs as hazardous material.

The city collects hazardous waste at various sites one Saturday a month between April and November.

The bulbs can also be returned to the IKEA store in the city's west end, or to Marchand Electric on Algoma Road.

Eventually, the bulbs end up at a facility in Southern Ontario where the mercury is reclaimed.