A method of deacidifying paper which involves the use of a material that is capable of supplying the deacidification agent in the form of a vapor. Ammonia, diethyl zinc, morpholine, or other volatile alkaline substances can be used, but most are not permanent in the presence of high relative humidity. Another method, and one which has received considerable notice, involves the use of cyclohexylamine carbonate. The books are interleaved with tissue paper impregnated with the compound, while loose documents may be treated by placing sacks containing the compound with the documents in box files. The deacidification agent is the free amine given off as a vapor.
Some authorities also contend that the vapor is potentially toxic.