Language & WorldFact
Never order jam "without préservatif" in France.
French "préservatif" is not a preservative but a condom: a thin sheath of latex or polyurethane. Food preservatives are "conservateurs". The false friend is so common it's a classic in language classes; Spanish ("preservativo") and Italian ("preservativo") hide the same trap.
Useful: On French food labels, look for "sans conservateurs".
Source: fr.wikipedia.org