Increasing limits on paint preservatives could lead to chemical-resistant biofilms, a prominent paint manufacturer warned at a recent conference.
Chemical Watch reports that Marian Rabone Johannesen, an official with Norwegian paints and coatings maker Jotun, told attendees at CW's Biocides Europe event that options for in-can preservatives are "being reduced one by one."
The report noted that the common preservatives methylchloroisothiazolinone and methylisothiazolinone — CMIT and MIT, respectively — are expected to be limited to concentrations of 15 parts per million in consumer products.
That threshold, however, amounts to a ban on the chemicals because the preservatives are not effective at that level.
Future regulations, meanwhile, could impact other preservatives, including formaldehyde, bronopol and zinc pyrithione.
Those restrictions could limit the ability of paint makers to vary their preservatives and, as a result, promote tolerance to them among biological contaminants.
In addition, Rabone Johannesen said the process of developing new preservatives is too costly for most paint manufacturers.