Vinegar syndrome is a problem with film made with cellulose triacetate base, in which it degrades and releases a smell resembling that of vinegar; indeed, deteriorating triacetate film produces acetic acid. The process can be slowed (with a molecular sieve, or by storing cool and dry in vented cans) but is impossible to stop. The reaction is autocatalytic and thus is possibly contagious between film reels, although no scientific study has confirmed this. For archival, films suffering from vinegar syndrome must be quarantined and copied onto a medium not susceptible to the problem.