Diesel pollution has gone unchallenged in the UK and Europe, and now we must implement diesel particular filter (DPF) testing in MOT tests to limit the effect of particulate matter emissions on public health.
In the WCRAQ Air Monitoring working party, Chair Ralph Wilce, Founder of Wijs-Air, led the conversation on why diesel vehicle emissions need to be addressed in the MOT test with particulate number measurements, as a result of car manufacturers using short cuts around emission regulations.
Guest speaker Beth Gardiner, Author of Choked: The Age of Air Pollution and the Fight for a Cleaner Future, spoke on the difference between the handling of the diesel-gate scandal in America and in Europe.
Gardiner described the smell of diesel in London, after moving from New York City, and developing a headache with feelings of light-headedness, which she had never experienced living in America. From there, Gardiner discovered that 40,000 Britons die every year due to air pollution, and was shocked to learn that children were even more affected.
The answer to this difference between London and New York City is the popularity of diesel, which are significantly more polluting fuels than petrol. Yet, the reason the UK and Europe are more polluted than America, is not just the difference in fuel choice, but the failure to enforce legislation. Whereas the US Environmental Protection Agency exists to reinforce and build up the Clean Air Act of 1970, after which pollution levels fell by 77 per cent.
Meanwhile, Europe and Britain have written regulations particularly for vehicles. Although this is often less ambitious than the equivalent American legislation, and fundamentally lacks a well-resourced agency to allow manufacturers to be accountable and hold them to regulations.
This became apparent after the diesel-gate scandal was brought into light, whereby car manufacturers, namely Volkswagen, sold vehicles across both Europe and America that were not wholly compliant with emission legislation.
Whereas the US criminally prosecuted Volkswagen and forced them to spend billions to compensate and buy back cars from drivers who had bought them in good faith. Yet, Europe has many times more of these cars on the road, and allowed manufacturers to get away with cheap software adjustments. As a result, there are 50 million diesel on road emitting three times more than the legal limit of nitrogen oxide. Moreover, they still do not meet the air pollution requirements in law currently in place today.
Ultimately, the US enforced the law and Europe did not. Consequently, air quality across Europe is in fact worse than America.
Guest speaker Gerrit Kadijk next spoke on the importance of particulate filter testing. Previously, the smoke opacity meter would be used to measure emissions, however this has become outdated as the issue of missing or faulty DPFs has grown.
A single missing or faulty DPF has the ability to emit the equivalent emissions of 360-miles of three-lane motorway traffic with working filters. Therefore, it is crucial to implement testing at MOT that will identify if a vehicle’s DPF is functional and present.
The new Particle Filter Test can detect DPF malfunctioning. Given the launch of several certified PN counters for the mandated Dutch DPF control test, suppliers are providing low-cost solutions (around £5k) based on either Condensation Particle Counting or Diffusion Charging technologies. The test is conducted at idle and takes less than a minute to complete. The limit set in the Netherlands for all vehicles first registered with a DPF has been set at one million particles (pt) per cubic centimetre (cm3).
Referring to the Volvo Euro 5b vehicle, the PN reading was 1.9 million pt/cm3 and would have failed the newly proposed Dutch test.
During the regulatory preparation of the new pass/ fail criteria, it was shown that the vehicle type approval limit as measured in total PN per km would be equivalent to approximately 50,000 pt/cm3 at idle.
In Germany, where only post Euro 6 diesel vehicles will be tested from January 1, 2023, a limit of 250,000 pt/cm3 will introduced. In Belgium, the fail limit for post Euro 5b cars and light vans will be one million pt/cm3 as in the Netherlands, but owners will receive a warning if the reading is >250,000 pt/cm3 <one million pt/cm3, which would become a fail during the next scheduled test.
In conclusion, to check the working of the DPF, either Particle Number or Particle Mass measurements are required. The light absorption principle as used in smoke meters is no longer fit for purpose on DPF equipped vehicles. A Particle Number performance standard for testing DPFs has now been developed and implemented in the Netherlands, Belgium, and Germany with Notified Bodies able to provide product type approvals to ensure traceability to primary standards. Despite examples of particle mass-based instruments, this standard has not yet been developed for regulatory DPF testing, although standards (such as MCERTS) do exist for air monitoring applications.
If you are interested in protecting the quality of air we breathe, email jason.pidgeon@visiecommunications to join the WCRAQ as a member.
