Gaseous toxic substances are especially dangerous because they are usually invisible and often odourless. It should be kept in mind that their physical behaviour is not always predictable since their temperature and pressure affect their properties dramatically as well as the effects of draughts.
In each category the required gas monitoring system can be one of two types. For minor risk applications, a simple gas monitor interfaced with a panel that sounds an alert may be adequate. Higher risk applications often require continuous (e.g., 4-20 mA) output sensors; however, before integrating the sensors into the control system consider the risk when the control system is unavailable, such as during upgrades, sensor replacements, service etc.
We offer both simple and complex systems.
INDUSTRIES WHERE TOXIC GASES ARE FOUND
AMMONIA
Refrigeration Plant
Clean Water Sites
Chemical Manufacturers
Fertiliser Manufacturers
Refrigerated Storage Depots
Food Processing Engineers
Plastics & Foams
Currency Manufacture CARBON DIOXIDE
Breweries
Food Manufacture
Mushroom Growing
Landfill Sites
Water & Sewage Plant
Refrigeration Plant
Chemical Industries CARBON MONOXIDE
Car Parks
Power Stations
Steel Works
Generating Plant
Mine Shafts
Chemical Companies
Garages
Metal Refinery & Heat Treatment
Underground Work
Nuclear Engineering
Laboratory
Car Manufacturing Plant
Tunnels
CHLORINE
Clean Water Plant
Paper Manufacturers
Chemicals & Plastic
Manufacturers
Food Industry
Textiles HYDROGEN CYANIDE
Gold Refining
Acid Gases
Petrochemical Plant
Chemical Engineers
Laboratory
Pharmaceutical Manufacture
Hospitals HYDROGEN FLUORIDE
Hospitals
Pharmaceutical
Leaded Petrol Manufacturing
Chemical Companies
HYDROGEN SULPHIDE
Dirty Waste Water Sites
Petrochemical Companies
Offshore Companies
Tunnelling Contractors
Man Entry Applications
Chemical Companies
Laboratories
Dye Makers
Mines NITRIC OXIDE &
NITROGEN DIOXIDE
All situations where there are
combustible emissions
therefore tunnels. car parks.
loading bays etc. SULPHUR DIOXIDE
Water Purification
Unclean Water Sites
Light Bulb Manufacturers
Power Stations
Paper Mills
Pet Food Manufacturers
Power Generating Plant
Steel Manufacturing
Exposures to toxic gases must be calculated on the Time Weighted Average (TWA) basis, which is the medium concentration relevant to a common 8 hours working day, at which it is considered that all employee can be exposed without injuring their health.
Exposure limits to toxic gases have been established by occupational safety agencies and may vary according to local directives. They commonly refer to the short term exposure limit (STEL) defined by the American Conference of Governmental Industrial Hygienists (ACGIH). The lower is the STEL –either expressed in ppmor mg/m3 –the higher is the compound toxicity.
