EN 943-1 sets the requirements for gas-tight chemical protective suits. This is the top level of chemical protection: the suit completely isolates the wearer from the environment, including from gases and vapours that pass freely through ordinary fabric.
Types
- Type 1a
- Breathing apparatus worn inside the suit
- Type 1b
- Breathing apparatus worn outside the suit
- Type 1c
- Air supplied from an external source at positive pressure
The gas-tightness test
The suit is checked by a pressure-retention test: it is inflated and the pressure drop over time is measured. This has to be done not only at the factory but before and after every use — a single split seam or damaged valve cancels the whole protection.
Operational reality
Working in a Type 1 suit is physically demanding: heat stress builds very quickly, vision is restricted, communication is difficult and movement is constrained. Working time is typically 15–30 minutes, limited by the breathing apparatus. Teams must never work with fewer than two people, and the decontamination procedure has to be set up in advance.