Type 4 Strip

ISO 11140-1 Type 4 Multi-Critical Process Variable Indicator for monitoring Low Temperature Steam Formaldehyde processes. The indicator strips are intended to demonstrate that the material has been exposed to a steam formaldehyde process to distinguish between processed and unprocessed items. Multi-critical process variable indicators react to all critical process variables (time, temperature and steam formaldehyde concentration). The backing of the strip is removable which exposes latex-free adhesive for easy application of the strip to packages during exposure and /or for record keeping purposes after exposure. Indicator can be used as a strip, label or both for record keeping post-exposure. True Indicating multi-critical process variable indicator strips contain no lead or other toxic heavy metals. Transition from violet to green when exposed to low temperature steam formaldehyde processes.