I work at a local bike collective and we get used helmets all the time. It is our practice not to give them out for 2 reasons, 1) we can not know if they have been in a crash unless there is visible damage, and 2) how do you clean a used helmet? There is the "ick" factor and also things like head lice. - any thoughts? I am curious what other bike collectives and community bike shops do with used helmets. FWIW - We have found a source of new helmets for under $10 that meet all of the crash and safety requirements.