Fee Carmichael from Planetes is a habitual smoker, but is generally unable to because oxygen is a precious commodity on space stations and space ships, so she has to do so in either a special smoking room or the little booth she constructed in the Debris Section office
If you knowingly mail materials that are dangerous or injurious to life, health, or property, for each violation, you face a civil penalty of at least $250 (but not more than $100,000), the costs of any cleanup, and damages
Cars would still get through town, but traffic would be slow, backed up, jerky, and would only get worse
This rating will usually be plastered front and center on the packaging of the purifier