Hi,This disposable 3M 8293 P100 mask is amazing. It blocks all foreign odors such as stinky, musty, moldy odors and tobacco smoke smells (and more).For starters, all disposable mask work/seal best on a clean shaven face (no mustache, beard or side burns). If you have facial hair, you will never get a good fit/seal when wearing a disposable mask and/or half mask respirator. If you don't have a correct seal, the mask will not do its job as advertised (another reason why soldiers are not permitted to have facial hair). The facial hair rule is mentioned a lot in 3M's online safety documentation.Secondly, according to 3M, a medium sized mask/respirator fits 80% of humans. If your nose is too large/long, try a larger mask. Test out the seal at your local store that has a garden center that sells plants/fertilizer. You will know you have a good fitting mask when you can't smell the plants/fertilizer. Do this first before wearing the mask in a hazardous situation/area.Thirdly, the World Health Organization (WHO) says that in cities with poor air quality, that a mask with a PM2.5 rating must be warn to protect your lungs. PM2.5 masks protect people from breathing in particles (particles in the air) that are larger than 2.5 microns. This mask protects people from particles 0.3 microns or larger and makes almost all smells/odors undetectable to the human nose.If you are traveling outside the US (or live in a smog plagued city like Las Angeles, CA) then, a P100 Mask is the best form of protection to protect your lungs.It's best to carry a few of these P100 disposable masks while traveling in other countries and to store opened masks in an air tight, resealable plastic bag (like a ziplock) to increase the life of the mask (an air tight plastic bag protects the mask from absorbing odors/moisture).This mask works best with DEWALT DPG82-11 Safety Glasses (prescription eyeglasses friendly). I own a pair of these safety glasses and I wear them over my prescription glasses comfortably without my prescription glasses fogging up due to the comfortable foam seal that travels around the frame of the safety glass lens).These can be found on Amazon for around $11 (see Amazon product title below):DEWALT DPG82-11 Concealer Clear Anti-Fog Dual Mold Safety Goggle.Bottom line: The 3M 8293 P100 Mask is amazing and is a great addition to bugout bags and emergency/survival kits in your vehicle/boat/motor home.Also, they block out stinky poo gas odor, urine odor and decomposing flesh odor (like dead animals found while fishing/hiking/camping).They are great to use while cleaning homes/businesses or using the restroom after someone else.I use these masks from time to time in moldy/mildew infested environments and I breath clearly without any issues.If your prescription glasses are fogging up, pinch the bendable metal strip (hard/firmly), within the mask, that rides on the bridge of your nose (above your nose just below the center of your eyes) to prevent warm, humid air leaving your lungs from fogging your glasses (or use this mask with the Anti-Fog Dewalt DPG82-11 Safety Glasses). If your glasses are still fogging up, pull the mask off your face about an inch and pinch the bendable metal strip, within the mask, before lowing the mask back in position over your mouth/nose for a better fit. The metal strip should form over the bridge of your nose and fit snug on the sides of your face below your eyes.Hope this helps others out.Note: I wrote this review without pay from anyone because I like how much this mask helps me out. I didn't receive anything for recommending the Dewalt Safety glasses either. This review included my personal review and facts from websites such as 3M (the manufacturer of this P100 disposable mask and WHO (The World Health Organization).Sincerely,Jacob LyleSurvivalGeek (On YouTube; my channel logo is a green smiley face)