>>1222668>>1222675It's also worth pointing out that you can potentially reduce your risk further by using pipe filters. Less popular in the USA than Europe, but still widely available. The three common choices are paper filters, charcoal filters, and balsa filters. Paper is just that - absorbent paper that picks up tar as it passes around or through. Charcoal filters are tubes containing activated charcoal with caps on both ends that allow smoke to pass through. Balsa filters are wedges of absorbent balsa wood that the smoke flows around, sold by Savinelli.
All three have a verifiable benefit in obstructing smoke, resulting in a cooler (and by association, safer) bowl. But that benefit can be reproduced by technique, or through an unfiltered pipe implementing something like the Peterson's 'standard system'.
What can't be easily reproduced without a filter is the accompanying reduction in tar and nicotine. All three do reduce the presence of tar and nicotine in smoke - however as there is a variety of producers (and styles) of paper and charcoal filters, it's unclear to what level presence of t/n is reduced. In the case of balsa; Savinelli contracted the European Union's research arm to study their filters, and found “..the filter has the ability to absorb 77% of the nicotine and 91% of the tar contained in tobacco without altering the flavour of same”.
That's their quote, and you'll notice they only say it's capable of absorbing those percentages - not that it always will. I can't find the full set of results anywhere so I can't vouch for them. But it certainly does absorb a ton of moisture and nicotine, and at least some tar. Here's a picture of a filter (6mm) after one use, snagged from the pipes magazine forums.
