Quick answer: use point detectors at defined leak sources and high-consequence hazards - reactors, storage, loading racks and compressor rooms. Use fixed multi-gas systems where several process gases must be observed together, and distributed monitoring where a release can move across an operating area or toward the fenceline.
The gas hazards
- Chlorine (Cl2) - OSHA ceiling 1 ppm; NIOSH IDLH 10 ppm.
- Ammonia (NH3) - OSHA PEL 50 ppm; NIOSH IDLH 300 ppm.
- Hydrogen (H2) - wide flammable range; leaks ignite easily.
- Hydrogen sulfide, VOCs and oxygen depletion from inerting and nitrogen blanketing. OSHA treats air below 19.5% oxygen as oxygen-deficient.
Where fixed detection fits
- Reactor and process units
- Tank farms and storage
- Loading and transfer racks
- Compressor and utility rooms
- Confined spaces
Where wireless fits
- Turnarounds and maintenance
- Fenceline and perimeter monitoring
- Emergency response
Regulations to know
OSHA PSM (29 CFR 1910.119), EPA RMP (40 CFR Part 68) and OSHA Permit-Required Confined Spaces (29 CFR 1910.146).
Safeguard products that apply
- SA-220 Fixed Gas Detector - single sensor, 4-20 mA and Modbus output, optional relays, rated -40 °C to +60 °C. Hazardous-location certification is in progress and not yet held.
- SA-XDS (diffusion) and SA-XES (aspirated) multi-sensor gas detection systems.
- SCX Gas Detection Control System.
- Foresight monitoring, analytics and compliance reporting.
FAQ
Point detection or multi-gas? Point detection fits a known single hazard; multi-gas fits areas where several process gases must be watched together.
Exposure limits cited are from OSHA and NIOSH. Confirm detector selection and placement against your site's hazard assessment, and verify specifications with Safeguard before specifying equipment.