Formic acid muaj nyob rau hauv secretions ntawm muv, tej ntsaum, thiab kab ntsig. Nws cov tshuaj aqueous yog tsis muaj zog acidic thiab corrosive heev, thiab tuaj yeem tsim cov tawv nqaij blistering. Hauv cov xwm txheej hnyav, nws tuaj yeem ua rau mob thiab mob, nrog rau qee zaus kev tsis haum tshuaj. Kev cuam tshuam rau nws cov vapor tuaj yeem ua rau conjunctivitis, daim tawv muag edema, rhinitis, bronchitis, thiab nyob rau hauv cov xwm txheej hnyav, mob ntsws chemical. Tom qab kev tswj hwm ntawm qhov ncauj, cov tshuaj muaj zog formic acid tuaj yeem ua rau lub qhov ncauj thiab lub plab zom mov, ua rau ntuav, raws plab, plab hnyuv los ntshav, thiab txawm tias tuag vim mob raum lossis ua pa tsis ua haujlwm.