The variety of jobs and tasks our customers set out to do continually amazes me. Here is a query from a recent customer about his task: In an upcoming job I will be melting lead and spraying acrylic and lacquer based paints. What mask and filters do you recommend to protect me from the fumes associated with these tasks? How does sizing on the masks work? For the lead fumes I suggest using a P100 (HEPA) filter such as the 3M 2091 Particulate Filter or the 3M 7093 P100 HEPA filter. P100 and N100 filters are rated for this application. Lower rated (N95) filters will not stop these dangerous and toxic substances. For spraying paint of the types you mentioned, I would recommend a different combination: the 3M 6001 organic vapor cartridge with a 5P71 prefilter, held on with a 501 retainer. All of these filter combinations will fit on either the 6000 or 7500 series half mask respirators. Both masks will work well, but the 3M 7500 silicone facepiece is more comfortable and seems to fit more people, while the 3M 6000 is more economical. There are ways of making a combination that will cover both paint and lead fumes, but it would be more expensive, both initially and in the long run. Sadly, there is no definitive way to know which size is correct in advance. About 75% of the masks we sell are size medium. If you think that you have a large face, then you likely do (or at least pretty close to large). That is about the best advice I can give on sizing. Looking for a reliable respirator? Check out the 8233 n100 mask that is meant for those who want the highest NIOSH-rated filter efficiency in a respirator. It is approved for lead abatement, metal fumes produced from welding, certain radioactive particulate material, and non-oil containing mists. As always, if you have a question about your specific application, feel free to contact us and ask. It’s better to be sure that you are getting the right protection than to breathe in something like lead fumes.