Do airlines allow these in carry ons?
Yes.
For definitive and up-to-date info, visit tsa.gov and go to the "For Travelers" section. This will help you avoid all of the myths and misconceptions about what can (and cannot) legally be carried on!
From the US, yes, they are allowed. Coming back from Europe might be a different story as they are not governed by the TSA.
I have carried disposable razors in my carryon back from Zurich and Venice with no problems. Never had a problem flying from the US. So, even if they take them as you are heading back home - no big deal.
No issues with these. It seems as if recently they have been most concerned about liquids so study the rules carefully is you have any.
If they are just the basic disposable razor, they are allowed.
For awhile, a few years ago, disposable razors were not allowed past security. (They are now.)
Al Roker told a story of how his disposable razors were taken away from him at the security checkpoint. After security, as he walked to his gate, he went into one of the sundry shops--and bought a pack of the exact same disposable razors he just had taken away. He put them in his bag and walked onto the plane.
Security issue or money-making scheme?
Thanks. I know that the TSA site states they are allowed, but I've heard stories of them being taken. Thanks so much for your responses.
Some Airline toiletry kits now contain a razor and shave cream. They were banned for awhile but now they are part of the kits again.
All in one disposable razors are explicitly allowed from British airports, but plain razor blades aren't.