Halma plc provides technology solutions in the safety, health, and environmental markets. It operates through four segments: Process Safety, Infrastructure Safety, Environmental & Analysis, and Medical. The Process Safety segment offers specialized interlocks that control critical processes safely; instruments that detect flammable and hazardous gases; and explosion protection and corrosion monitoring systems. This segment serves the gas detection, industrial access control, pressure management, and safe storage and transfer markets. The Infrastructure Safety segment provides fire detection systems, specialist fire suppression systems, elevator safety systems, people and vehicle flow technologies, and security sensors. It serves the fire detection and suppression, and elevator markets. The Environmental & Analysis segment offers opto-electronic technology and sensors, flow gap measurement instruments, and gas conditioning products, as well as solutions for environmental data recording, water quality testing, water distribution network monitoring, and UV water treatment. It serves the optical analysis, water analysis and treatment, and environmental monitoring markets. The Medical segment provides devices that assess eye health; assist with eye surgery and primary care applications; critical fluidic components used by medical diagnostics and original equipment manufacturers; and laboratory devices and sensor technologies used in hospitals to understand patient health. This segment serves the life sciences, health assessment, and therapeutic solutions market. The company was incorporated in 1894 and is headquartered in Amersham, the United Kingdom.