The ESLI technology is an end of service-life indicator for respirator cartridges used to block contaminant gas inhalation in industrial working environments. The indicator is a porous fiber that absorbs contaminants in a manner very similar to activated carbon used in cartridges. A section of fiber placed inside the cartridge indicates its saturation, warning the user that the cartridge no longer offers adequate protection.
FISO plans to fine-tune the technology for industrial application, releasing a commercial product.
More than 10 million cartridges per day are used in North America. Currently there are no efficient and economic ways of detecting the end of service-life of these cartridges. The most common current method to determine if the cartridge is no longer useful is for the worker to detect the odor or taste of the contaminant or to sense a throat irritation. April 1998 legislation by the Occupational Safety and Health Administration (OSHA) requires that respirator cartridges be equipped with ESLI as soon as such a device becomes available.
Edited by Kristin Lewotsky