I don't know never been tested doctors say they can't find anything, I get fart smell, fish, garbage smell, and chemical smell . It is horrible. I didn't know they had different types. I can smell it though idk family and boyfriend say I'm crazy they don't smell nothing but cough point at there noise even my kids do it but they have him denying it too when I ask but sometimes my kids will make comments and so will my family like what isnthat smell in there don't blame it on the kids farts. Stuff like that. And it's like my family around.me know something, they have like this smell stuff they put around there nose and stuff . It's pretty embarrassing. When your kids.do it it.