Honeywell Analytics offers Toxic Gas Monitors. Honeywell Analytics products are manufactured in accordance with UL 2034, BS 7860:1996, and EN-50291:2001 and ISO 9001:2000. The Toxic Gas Monitors are of MDA brand and are useful for protecting employees, processes and local communities from the dangers of toxic gas leaks. Chemcassette Technology is the heart of these systems. It is based on classic colorimetry. The Chemcassette detection system is the single most important part of an MDA toxic gas monitoring system. Chemcassettes use a dry reagent medium to collect and analyze air to detect gas leaks. When the Chemcassette is exposed to a target gas, it changes color in direct proportion to the concentration of gas present. MDA Scientific monitors can read color intensity changes and determines the gas concentration by comparison to a known gas response pre-programmed into the instrument.