I was raised in process safety, with a focus on flammables, and I was taught that one thing you just don't allow into your flammable process is plastics! But even I was unaware of how much plastic I had always overlooked, which was right under my nose, such as my LOTO tags.
New Hazard - Static Discharge from Isolation Tag
CCPS was recently (January 2023) made aware of a newly identified hazard regarding the ability of plastic or coated isolation tags to hold a sufficient static charge to act as an ignition source for flammable gases—even if the tags have an antistatic coating.
These tags are readily available in the marketplace and are typically used with LOTO label printers. The tags were evaluated for surface resistivity and charge transfer following IEC test methods. They were found to pose an ignition hazard for Zones 0, 1, 2, and Gas Groups IIA, 118, and Zone IIC. The tag size was reduced to an area of 11 in2 (71 cm2) and was still found to be an ignition hazard in all of Zone O and Gas Group IIC for Zones 1 and 2.
CCPS recommends that operating companies ensure that isolation tags used in hazardous areas are incapable of holding and discharging an electrostatic charge that would enable them to serve as an ignition source.
