Source: Chemical & Engineering News, December 16, 2013
Author: Cheryl Hogue
Eliminating a toxic substance from a product’s ingredients seems like a straightforward way to improve product safety. But when a toxic chemical gets removed from a product, some other substance — or substances — goes in as a replacement to carry out that ingredient’s function, such as softening plastic or helping remove grease. Such a switch is intended to resolve the problem. But in some cases this situation can lead to what is being called “regrettable substitution.”
For example, brake cleaner, which auto mechanics use, once contained chlorinated solvents, primarily methylene chloride. But in the 1990s, pollution control regulations pushed manufacturers of the cleaner to rid their products of chlorinated solvents. In place of these compounds, brake cleaner makers substituted n-hexane, which performs well in their products.
By the late 1990s, physicians began to report that auto mechanics using brake cleaner were suffering nerve damage, according to the Centers for Disease Control & Prevention. Since the 1960s, n-hexane has been known to be neurotoxic. Product makers had swapped chemicals with a significant pollution downside for a substance that posed a serious health risk to workers.
TURI’s Note: The TURA Administrative Council has voted to designate methylene chloride as a Higher Hazard Substance. See TURI’s Policy Analysis for Methylene Chloride.