Gypsum industry news

US: Carbon monoxide (CO) from external sources can easily penetrate gypsum wallboard according to a study published in the Journal of the American Medical Association by Neil B Hampson, James R Holm and Todd G Courtney of the Virginia Mason Centre for Hyperbaric Medicine. The study is believed to be the first to examine the ability of CO to diffuse through gypsum wallboard.

In the study, a plexiglas chamber divided by various configurations of gypsum wallboard was used to determine whether CO diffuses across wallboard. Wallboard of various thicknesses were used. CO test gas was infused into the chamber and then CO concentrations were measured once per minute in each chamber for 24 hours. The authors sought to determine how rapidly a concentration of CO toxic to humans would be reached in the non-infused chamber and whether diffusion would then continue. The researchers found that CO diffused across single-layer gypsum wallboard of two thicknesses, double-layer wallboard and painted double-layer wallboard.

"Gypsum's permeability to CO is due to its porosity. The ability of CO to diffuse across gypsum wallboard may explain at least some instances of CO poisoning in contiguous residences. Exempting residences without internal CO sources from the legislation mandating CO alarms may put people in multifamily dwellings at risk for unintentional CO poisoning," said the study. Carbon monoxide poisoning causes about 500 accidental deaths annually in the US.