Subsequent research questioned whether the charcoal filter might have actually made Lark a more dangerous cigarette.

It was time to pull the charcoal filters and bake the volatiles out of them again.

Now if she'd just changed out the charcoal filters.

Sometimes when the charcoal filter was not used, it had a yellow cast and tasted like coal oil.

Starting in 1983, those homes were fitted with charcoal filters, paid for by the oil spill fund.

Protect yourself by wearing a respirator with a charcoal filter.

The water in each well will be tested before charcoal filters are installed, he said.

But charcoal filters would remove all the contaminants, he said.

I cleaned it out, changed the charcoal filters, and stepped up the oxygen generator, the work taking about three hours.

Kent now uses charcoal filters (a form of activated carbon).