Vehicle Emissions

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.

Vehicle Emissions

Please find information relating to Vehicle Emissions, including:

Emissions - Smoke or other debris
Emissions - Noise

Exhaust emissions

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 I and Euro II) and 99/96 (Euro III and Euro IV) specify maximum limits that can only be measured on a testbed and, as such, can be regarded as the responsibility of the manufacture-rather than the user. The Euro III 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 IV was introduced for new vehicles registered from 1 October 2006.
Euro V was introduced for new vehicles registered from 1 October 2009.
Euro VI was introduced for new vehicles registered from 31 December 2013.

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. The limits are shown here with the earlier limits in brackets.

Turbocharged 3.0m-1 (3.7)
Naturally aspirated 2.5m-1 (3.2)

From 1 July 2009, more stringent smoke level tests were introduced at the annual test on vehicles equipped with Euro IV engines or better. Vehicles in this category, which were registered from 1 July 2008, are required to pass a smoke test with a reduced smoke limit of 1.5m'.

From 20 May 2018, for vehicles first registered from 1 January 2014, 0.7m’1 for all C1 engines or the level specified on the manufacturer's plate, whichever is lower?

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.

Full details of emissions data is detailed in the Department of Transport publication.

Emissions 17Th Edition (pdf, 0.8 MB)

Legislation limiting the emissions from petrol engine 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
In order to examine the working of the machinery following the failure
In order to work the machinery for a purpose other than driving the vehicle
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 under Road Traffic (Vehicle Emissions) (Fixed Penalty) (England) Regulations 2002.

The following link provides guidance and further information

C&U Regulations – Table of Contents
https://www.legislation.gov.uk/uksi/1986/1078/contents/made