Section 06 Products of the chemical or allied industries 29 Organic chemicals 29 07 Phenols; phenol-alcohols 29 07 23 4,4'-Isopropylidened-iphenol (bisphenol A, diphenylolpropane) and its salts. 29 07 23 00 4,4'-Isopropylidened-iphenol (bisphenol A, diphenylolpropane) and its salts. Commodity Code Description 29 07 23 00 000 4,4'-Isopropylidened-iphenol (bisphenol A, diphenylolpropane) and its salts.