Homebrew PCBs

Are you guys talking about something like this?:
http://www.lowes.com/pd_215253-98-65021HA1-A_0__?productId=3082307&Ntt=dust+mask&Ns=p_product_price|1&pl=1&currentURL=%2Fpl__0__s%3FNs%3Dp_product_price|1%26Ntt%3Ddust%2Bmask

How do you know what it will filter out? (like etchant fumes?)


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