Carbon reporting: questions and answers

Q: What is the benefit of calculating carbon emissions? 

A: Calculating and reporting carbon emissions will show where your CO2 emissions come from and help you plan how to reduce your emissions; it is important for tackling the challenge of climate change and the drive towards Net Zero. Customers are increasingly demanding the data from their supply chains and often, reducing emissions can reduce costs.

Q: What are Scope 1, 2 and 3 emissions?

A: The Greenhouse Gas Protocol categorises a business’ emissions into Scopes 1, 2 and 3. Scope 1 covers emissions released directly from a company’s controlled assets, for example those from onsite industrial processes or company vehicles. Scope 2 emissions are those released indirectly from the company but within the company’s control. An example is the purchase of electricity. Scope 3 emission are indirect emissions out of the company’s control and account for around 70% of a business’ carbon footprint.

Q: Is there an industry standard checklist of exactly what should be measured for each scope of emissions?

The Greenhouse Gas (GHG) Protocol defines the Scopes and what they cover - https://ghgprotocol.org/tools-resources - but there is no comprehensive, universally agreed and accepted checklist.

Q: What is the international standard, and should I align to it? 

A: The international standard for organisational GHG quantification and reporting is ISO 14064. There are other schemes an organisation can align to, but supply chains are international and so alignment with and verification against ISO 14064 is likely to dominate and be expected by customers. 

Q: Are there standard methodologies for carbon calculation and reporting?  

A: There are many methodologies for calculating carbon emissions. The CHSA’s advice is to work with a consultancy able to adapt their approach to the needs of your business.

A variety of organisations will independently verify data, however verification via a UKAS (United Kingdom Accreditation Service) accredited body is the ‘gold standard’ in the UK.

Q: Which emission factor database would be recommended for calculating Scope 3 emissions?

A: It depends on where you are and what you're measuring. The Carbon Accounting Alliance is collaborating across the industry to produce guidance on which emissions factor databases are best for which use. A beta site is under development that will list a lot of the most common databases: https://wiki.carbonaccountingalliance.com/index.php?title=Portal:Emission_Factors 

Watershed (watershed.com) has published an emissions factors database, CEDA, for open-source use with attribution.

DEFRA (The Government Department for Environment, Food and Rural Affairs) has published a set of emissions factors covering transport, materials, waste etc: https://ghgprotocol.org/Third-Party-Databases/Defra.

Q: Can you recommend any reference materials?

A: The UK Business Climate Hub is a good resource, designed specifically for SMEs. It is a Government supported portal: https://businessclimatehub.uk/become-a-net-zero-business/

SMEs can also make use of free carbon calculator tools, such as Clean Growth UK.

The EU has published guidance called Voluntary SME. It can be considered a sustainability standard. The UK is developing something similar - the SME Sustainability Data Reportingstandard. The intention is set out a consistent format and structure for reporting and so standardise the data being requested of SMEs by large organisations.  It is currently out for consultation: https://www.bankersfornetzero.co.uk/wp-content/uploads/2025/06/From-Burden-to-Benefit.pdf.

Q: Can I compare one organisation’s carbon emissions to another’s?

A: It can be challenging to compare the carbon footprints of different organisations unless you are certain the measurement boundary and approach taken are the same or very similar. If one organisation is measuring emissions more robustly, overall emissions may appear higher when the reality is the other organisation is not measuring as much. Generally, the most practical is to focus on how an organisation is progressing against its own targets and measurements.

Q: Given the emphasis on reducing carbon, has there been any progress in comparing the carbon impact of biotech cleaning products versus traditional petrochemical-based ones?

A: Not to our knowledge. It is extremely difficult to compare carbon emissions across technology areas in this way because of the different methodologies used. 

The CHSA’s advice is evaluate the transparency of the organisation’s approach, the quality of the data, and whether the data has been independently verified. 

Lorcan Mekitarian is chair of the Cleaning & Hygiene Suppliers Association

For more information, visit www.CHSA.co.uk