Biphenyl
The short version
An aromatic post-harvest citrus fungicide — banned in the EU since 2003 over toxicity concerns.
It's allowed, but comes with clearer cautions — such as reactions in sensitive people, stricter limits, or contested safety. The Safety section below explains why.
Where it comes from
Manufactured by dehydrogenation of benzene at high temperature, or recovered from coal tar distillates. The simplest aromatic hydrocarbon dimer.
How it's used
Historically applied to citrus packing tissue and crate liners as a vapor-phase post-harvest fungicide. The vapor penetrates the wax coating and inhibits Penicillium growth without direct fruit contact. EU food use was revoked in 2003. Still used in industrial chemical synthesis and as a heat-transfer fluid.
Safety profile
ADI revoked along with EU food authorization. Banned as a food contact material in the EU since 2003 because of cumulative toxicity concerns (reproductive, neurological, and possible carcinogenic signals at chronic high doses).
Physical & chemical properties
White crystalline solid with a faint, pleasant odor. Practically insoluble in water; soluble in ethanol and oils. Volatile enough to function as a vapor-phase fungicide.
Regulation worldwide
Banned for food use in the EU since 2003. Permitted in some non-EU citrus-exporting countries (Argentina, South Africa); some US import tolerance remains for receiver-country labeled fruit.
Educational information only. Not medical or dietary advice.