Emmissions
Introduction
Regulation 61 and 97 Road Vehicles (Construction and Use) Regulations 1986 sets out the regulations on Smoke Emissions and Noise; combined
these regulations deal with Pollution Control. Although under EU Directives on emissions and noise, the emphasis is intially placed upon
the vehicle manufacturers to ensure that the product produced complies, it should equally be noted that when the vehicle (having satisfied
manufacturing criteria) there is a significant role to play here by the driver of the vehicle(s), and to a lesser degree the Operators
maintenance provider in ensuring that these regulations are kept abreast of.
Emissions - Smoke or other debris
A distinction must be made between emissions legislation as laid down in the EU directives which deal mainly with the construction of the
vehicles and the UK domestic legislation which deals with their use. Directives such as 91/542 (Parts 1 and 2 of which are better known
as Euro 1 and Euro 2) and 99/96 (Euro 3 and Euro 4) specify maximum limits that can only be measured on a test bed and, as such, can be
regarded as the responsibility of the manufacturer rather than the user.
The Euro 3 standard which was introduced for new vehicles from 1 October 2001 used the European Steady State Test Cycle. In addition those
engines fitted with a particulate filter and/or DeNOx catalyst have to be tested under the European Transient Cycle. Euro 4 was
introduced for new vehicles registered from 1 October 2006.
UK domestic legislation on the other hand is aimed at vehicles in service and includes checks on the emissions of carbon monoxide (CO) and
hydrocarbons (HC) from petrol engines and black smoke from diesel engines.
The use of the smoke meter at the annual test was introduced in September 1992 for turbocharged and naturally aspirated diesel engines
followed by a reduction in the maximum permitted smoke levels on 25 September 1995 - see table below.
| Engine Type | New Limit | Previous Limit |
|---|---|---|
| Turbocharged |
|
(3.7) |
| Naturally aspirated |
|
(3.2) |
Legislation limiting the emissions from petrol engined vehicles in service was introduced in 1991 and was updated on 1 January 1996 to include vehicles equipped with advanced emissions control systems such as three-way catalytic converters. The limits, which can be enforced at roadside checks as well as at the MOT test, are as follows:
- for vehicles first used before 1 August 1986, a maximum of 4.5 per cent CO;
- for vehicles first used on or after 1 August 1986, a maximum of 3.5 per cent CO;
- for all vehicles, a requirement that the HC content does not exceed 0.12 per cent of the total exhaust emissions from the engine by volume;
- for engines first used on or after 1 August 1992 and equipped with advanced emissions control systems, the limits for CO emissions are based on the manufacturer's specification or on the default value specified in the directive where the specific data is not available.
Regulation 61 Road Vehicles (Construction and Use) Regulations 1986 states that every vehicle shall:
- be constructed and maintained so as not to emit any avoidable smoke or avoidable visible vapour, or
- comply with a relevant EC or ECE directive.
It is an offence for a person to use, cause or permit to be used on a road any motor vehicle from which any smoke, visible vapour, grit, sparks, ashes, cinders or oily substance is emitted if that emission causes or is likely to cause damage to property or injury or danger to any person who is, or who may reasonably expect to be, on the road.
There are numerous technical requirements for vehicle emissions. Certain Local authorities are now empowered to authorise persons to test for emissions and fixed penalty tickets may be issued - Road Traffic (Vehicle Emissions) (Fixed Penalty) (England) Regulations 2002.
Emissions - Noise
Regulation 97 Road Vehicles (Construction and Use) Regulations 1986 states that no motor vehicle shall be used on a road in such a manner
as to cause any excessive noise which could have been avoided by the exercise of reasonable care on the part of the driver.
Stopping engine when stationary
Regulation 98 Road Vehicles (Construction and Use) Regulations 1986 states that the driver of a vehicle shall, when the vehicle is
stationary, stop the action of any machinery attached to or forming part of it so far as may be necessary for the prevention of noise or
exhaust emissions except:
- when stopped in traffic, or
- in order to examine the working of the machinery following failure, or
- in order to work the machinery for a purpose other than driving the vehicle, or
- machinery connected with gas propulsion units.
This offence has been extended to include exhaust emissions as a reason to turn off the engine. Certain Local authorities are now empowered to authorise persons to issue fixed penalty tickets for the offence - Road Traffic (Vehicle Emissions) (Fixed Penalty) (England) Regulations 2002.
Further Reading
For further information relating to the subject of emissions, please use the links below.
Roadside Checking of vehicle Emissions - VOSA
