Carbon Monoxide Detectors
Carbon monoxide is colourless, odourless and produced wherever fuel burns without enough air. At work it is a risk from engines, boilers, furnaces, forklifts, generators and any combustion in an enclosed space.
Industrial sources of CO
Boiler houses and plant rooms
Vehicle workshops, loading bays and car parks
Foundries, kilns and furnaces
Commercial kitchens
Generators, pumps and engines used in confined spaces
UK exposure limits
EH40 sets workplace exposure limits for CO of 20 ppm (8-hour TWA) and 100 ppm (15-minute STEL), reduced in 2020 from the previous limits.
Why a domestic alarm is not enough
Domestic CO alarms are designed for homes and are not linked to workplace exposure limits or set up for personal monitoring. Workplaces need detectors that alarm at the levels your risk assessment requires and that can be bump tested and calibrated.
Personal and fixed CO detection
Personal CO monitors clip to the collar and suit lone workers, maintenance teams and engineers moving between plant rooms.
4-gas monitors include CO for confined space entry.
Fixed CO detectors protect plant rooms, car parks and kitchens and can switch ventilation or shut off gas.
Choosing a CO detector
For individuals, a personal CO monitor clipped in the breathing zone gives warning wherever they work. For plant rooms, car parks, loading bays and workshops, fixed CO detectors watch the area continuously and can switch on ventilation. Where CO is one of several hazards, a 4-gas monitor covers it alongside oxygen, flammable gas and H2S.
The UK limits are 20 ppm as an 8-hour TWA and 100 ppm as a 15-minute STEL. Our EH40 reference for common gases lists the limits for other gases.
Hydrogen and CO sensors
Standard CO sensors also react to hydrogen, which can cause false readings near battery charging or electrolysis. Hydrogen-compensated CO sensors are available; tell us if hydrogen may be present.
Bump testing and calibration
A bump test exposes the detector briefly to a known gas to prove that the sensors respond and the alarms sound. It takes about a minute and should be done before each day's use. A full calibration adjusts each sensor against certified gas and is normally needed at least every six months, or sooner if a bump test fails, the monitor has been dropped or it has seen a high exposure.
Our calibration service covers any brand of portable or fixed detector at standard rates by instrument type: from £40 for a single gas monitor, £50 for a 4-gas monitor, £90 for a multigas monitor and £140 for a PID. Each instrument comes back with a traceable calibration certificate.
Training your team
A detector only protects people who know how to use it. Our gas detection training covers start-up checks, bump testing, reading alarms and what to do when one sounds. We run on-site courses anywhere in the UK from £750 a day, or a three-hour online session from £350.
Talk to our engineers on 01489 326031 or email sales@7solutions.co.uk. We supply, hire, calibrate and train across the UK.
Frequently asked questions
What are the UK exposure limits for carbon monoxide?
EH40 sets 20 ppm as an 8-hour time-weighted average and 100 ppm as a 15-minute short-term exposure limit.
Can I use a domestic CO alarm at work?
Domestic alarms are designed to warn occupants of a home and alarm at levels and times that are not linked to workplace exposure limits. Workplaces should use personal or fixed detectors set to EH40 limits.
Where is fixed CO detection used?
Plant rooms and boiler houses, car parks, loading bays, kitchens, workshops and anywhere engines, burners or generators run indoors.
Do lone workers need a personal CO monitor?
Where CO may be present, a personal monitor worn in the breathing zone gives the individual an immediate warning, which is especially important for people working alone.