Petrol-driven engines

Potential sources of carbon monoxide hazards include metal-refining processes, in which it is formed as a byproduct and used as a fuel (LEL 12.5%), and running vehicle engines (particularly petrol-driven) or gas-fired heaters in poorly ventilated confined spaces. It is also a feedstock in the manufacture of a variety of chemicals, e.g. methanol, acetic acid, phosgene and oxo-alcohols. 

The first air-quality sensors for cars used a Japanese sensor element in which a sensitive tin-oxide material was layered onto a ceramic carrier. This sensor matches very well the requirements for a sensor for controlling air quality in petrol-driven vehicles. In 1986 the first generation was completed it used an Sn02 sensor and detected more than 85% of exhaust gases. However, diesel engines also produce nitrogen oxides, which can not be detected by tin-oxide sensors. 

A petrol- or diesel-driven vehicle or a trailer towed by a petrol- or diesel-driven vehicle is used. It is better to use either battery-operated trucks or diesel engine vehicles in an enclosed explosive area. If a petrol engine vehicle is used, it must be parked outside the traverse of an explosive building or at least 5 m away from an untraversed building. 

Environmental airborne hazards in the form of pollution can be produced from petrol or diesel engine powered vehicles or machinery. This is a particular problem when the engines are poorly maintained or being overworked. Carbon monoxide from petrol or diesel driven plarrt is a serious health problem when operated in enclosed areas. 

Long-term factors which will increase the electronic content of cars include the arrival of fuel-cell powered cars and the further development of hybrid vehicles where the petrol engine is used to generate electricity using an alternator and the wheels are driven by electric motors, power being stored in... 

An intermediate step in the search for an acceptable battery-powered car may be some form of hybrid vehicle, which uses an auxiliary power source (e.g. a petrol or diesel engine, or perhaps even a small fuel cell) as well the battery-driven electric motor. Several prototypes are currently under development. The auxiliary engine extends the range achievable and can be used to recharge the battery whilst in motion. Aithough these are iow rather than zero-emission vehicles, they may be an acceptable short-run compromise, especially if the auxiliary motor is restricted to non-urban use. 

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