Written evidence submitted by Norman Highnam (RDF0005)




About Norman Highnam, Member of the Institute of Refrigeration


A leadership awarding winning and published transport refrigeration consultant having spent over 35 years in the industry at all levels from engineering to senior board level appointments.


I look to help people understand the industry and I actively lobby for engineer safety including the removal and control of emissions in the transport refrigeration sector.


Emission Control in the Cold Chain and engineering and driver safety in the Cold Chain sector.

I would like to bring to the committee attention to the forgotten emitters in the transport supply chain.

The diesel transport refrigeration units

There are about 70k to 100k of these units operating in the UK with UK haulage companies and supermarkets etc with many more entering the UK via the ports and collecting or delivering temperature controlled goods including foods – medicines – antiques and even formula 1 car tyres.

Each load and characteristic of the load will be different with lot of regulations and tracking of the temperature of the load and the conditions of the load being carried.

The trucks that the fridges are connect to are regulated under the Euro6 regulations on emissions and are tested annually for emissions as part of the MOT standards. These trucks are monitored as part of the Ultra-Low Emission Zones and Low Emission Zones inforce in various towns and cities in the UK now.

Operators of these trucks and older trucks have to pay fees- fines to enter these zones due to the emissions from their trucks.

In a report commissioned by Transport Scotland as part of their Air Quality review and completed by Zemo Partnerships a emission test was carried out on transport refrigeration equipment.

Air quality (transport.gov.scot)

It found that transport refrigeration units emit substantially higher emissions than the Euro6 truck they are fitted to with some levels between 100 -1000 times higher.

Section of the report detailing the figures.

It also showed the level of soot emitted during the testing.

Photo 1 - The filter image on the left is from the transport refrigeration unit, the right is a Euro6 van.


Photo 2 – The image below shows the exhaust stains of the transport refrigeration diesel engines on the roof of the trucks that they are fitted to.

The images are clear indicators of the soot and the Zemo Partnership report confirmed the levels of the emissions from the transport refrigeration diesel engines in comparisons to the Euro6 engines used in the trucks.

These trucks and trailers can enter a ULEZ with the fridge diesel engine running with no regulation attached to controlling the emissions or even to recognise the emission as part of the ULEZ.

These trucks and trailers go to schools and to hospitals every day with the diesel engines running with no regulation to stop them.

Imagine an area with a few large distribution centres for the supermarkets and the haulage companies, with each yard having about 100-200 of these trucks and trailer transport refrigeration units. These could be running on diesel engines waiting to be taken out on the delivery run. If there was 7 or 8 of these yards in one area then you could have up to 1000 transport refrigeration units running in one area near a town or in a city. Then add to that all the trucks and trailers that deliver into the distribution centres 24hrs a day, you could have up to 1200 -1500 transport refrigeration units running on diesel 24hrs a day.

With no tests or checks on them or regulations to make them plug into electric standby, and if they did then they might fall foul of the Climate Change Agreement ( CCA) about power reduction credits which many cold stores already collect.

This is called a cluster emission effect and is little known about in the UK.

But in the state of California the California Air Resource Board have carried out tests and they have observed the cluster effect of warehouses and shop deliveries based on the use of diesel powered transport refrigeration units and they have observed the effect on the local population that surround the sites and or work in the sites.

Photo 3 is a image from the CARB report the concept is the effect of taking the diesel engine transport refrigeration units out of the cold chain and linked back to cancer risk.

They are so concerned they have passed a law to ban and set in place a phase down of all diesel driven transport refrigeration equipment used in the state and entering the state , all diesel driven transport refrigeration systems fitted to trucks are banned from 2030 and trailers by at the latest 2034.

The full report is via this link.




Photo 4 Image from the CARB page confirming the first enforcement steps.

New Transport Refrigeration Unit Regulation in Development | California Air Resources Board

As you can see clearly the USA State of California which operates a similar level of trucks and trailers as the UK, has taken affirmative action to remove the issue of diesel transport refrigeration emission.

Alternative solutions are starting to be adopted by haulage companies in California and new companies have entered the market place, 2 main players are still offering diesel solutions rather than non-diesel solutions.

These 2 main players are both dominant in the UK market place as well and both are USA based companies.

The UK Government has taken some steps toward change with the banning of the use of red diesel in the sector from April 2022 as this was seen as a barrier to investment in new non diesel technologies.


The UK Government also set up a £40m fund program via the BEIS team to find a replacement for sectors using red diesel – with construction – mining – quarrying and also to include the transport refrigeration sector in its scope document.



Photo 5 Image is a section from the report completed by E4tech (UK) Ltd and Cenex for UK Department for Business, Energy and Industrial Strategy March 2021 and titled

“Red Diesel Replacement, Stakeholder Engagement Pre Innovation Study,Final Report for BEIS”

Which clearly shows that the transport refrigeration unit is included.



Photo no 6 Image is a Parlimentry question raised to DEFRA on the subject with confirmation that the Transport Refrigeraiton unit are included. No alternative text description for this image


When the competition came out the Transport Refrigeration units were excluded from the report and it was confirmed in a virtual meeting between myself and the project team, that due to an error in the red diesel usage reports at the Office of National Statistics the transport refrigeration sector was dropped.

I talked to the ONS and they confirmed that they do not register the use of red diesel in transport separate from diesel used in trucks. Diesel is diesel in their eyes. ( Which put the diesel usage of truck figure out as well then). 

So the transport refrigeration sector has been omitted from any help to remove diesel from its day to day operation.

This Link is to the revised competition excluding transport refrigeration.

  Red Diesel Replacement Phase 1 Competition: guidance (publishing.service.gov.uk)

Just to confirm these are my estimates of red diesel usage in the transport refrigeration sector sent to the BEIS team after the virtual meeting to reconfirm their incorrect figures. 

Photo 7 Image from emial sent to BEIS Team 01/10/2021


Photo 8 Image from the BEIS report indicating the main user and volume of red diesel used.