Formaldehyde

Abstract

Formaldehyde, as an aqueous solution ranging from 37 to 50 wt%, continues to be the preferred aldehyde for reaction with phenol for the preparation of phenolic resins. Over 30 million metric tons of formaldehyde represent the global worldwide consumption of formaldehyde for an array of products, besides phenolic resins. These include urea formaldehyde resins, melamine formaldehyde resins, polyacetal resins, methylenebis (4-phenyl isocyanate), butanediol, pentaerythritol, and others.

The two basic processes to produce formaldehyde from methanol – the silver catalyst process and the metal oxide process – are described along with the strengths and weaknesses of the respective processes. Furthermore, methanol plant siting location is a factor due to raw material (natural gas) and energy costs.

The controversy regarding the classification of formaldehyde as a human carcinogen remains unsettled. In 2004, the International Agency for Research on Cancer (IARC) of the World Health Organization reclassified formaldehyde from a group 2A substance (probable carcinogen to humans) to a group 1 (carcinogenic to humans) substance. Yet no government regulating agency has classified formaldehyde as a known human carcinogen. The studies that acknowledged formaldehyde to be a human carcinogen are being re-analyzed with additional research by IARC to re-examine its current classification of formaldehyde. By end of October 2009, despite strong disagreement among participants of the voting body, who were evenly split at the vote, IARC concluded that there is sufficient evidence in humans of a causal association of formaldehyde with leukemia. Industry disagrees with this conclusion and believes that the weight of scientific evidence does not support such a determination. A review of all of these data is still in process but impact on possible governmental reclassifications expected to be seen in 2010.