FOI Ref: FOI/2021/2666​

You asked

Please supply the following information for each of the below for the past ten years:

  • How many (a) poisonings and (b) deaths have been reported due to Carbon Monoxide (CO)?

  • Of these, how many reported poisoning / deaths were at home?

  • Of these, how many reported poisonings / deaths were due to a combination type boiler?

  • Of these, how many reported poisonings / deaths were due to a combination type boiler which had been issued with a gas safety certificate in the past 12 months?

  • Of deaths and poisonings due to a combination style boiler can you please break results down into owner occupied, private rented and social rented accommodation.

We said

​Thank you for your enquiry.

Our mortality data is derived from information collected at the point of death registration, and the cause of death is coded using the International Classification of Diseases, using version 10 (ICD-10).

Unfortunately, we do not hold data on the number of poisonings where there has been recovery. We only hold the number of poisonings resulting in death. NHS Digital may be better placed to assist with this query. They can be contacted via email at

Deaths where the underlying cause is assigned to an external cause are also assigned at least one nature of injury code (Chapter XIX) or a post-procedural code not within Chapter XIX. This means it is possible to have more than one nature of injury code for a single death. However, it is necessary to select which one of the nature of injury codes is to be identified as the one causing death. This one cause code is referred to by ONS as the secondary cause. More information is available in section 9.2 of the user guide to mortality statistics which you can access via the following link:

Using ICD-10, deaths from toxic effects of carbon monoxide would be given a nature of injury code of T58.

The total number of deaths by age, sex and secondary cause of death for 2010-2020 are available from Table 6 (2010 – 2017) and Table 8 (2018 – 2020) of Deaths registered in England and Wales (Series DR) :

We also hold ad-hoc analysis published on our website for 2011 to 2017 showing the total number of deaths where toxic effects of carbon monoxide were mentioned on the death certificate. This can be accessed via the following link: Number of deaths where Carbon Monoxide was mentioned on the death certificate in England & Wales 2011 and 2017.

Deaths from Carbon Monoxide in at home

Unfortunately, we do not hold analysis showing deaths from ICD-10 code T58 between 2010 to 2020 specifically in the home. To fulfil this request, we would need to create bespoke analysis. Under the Freedom of Information Act 2000, Public Authorities are not obligated to create information in order to respond to requests. We therefore consider this to be information not held.

However, information about deaths due to CO and place of occurrence (such as the home) may be available to commission as bespoke analysis. Such services would be subject to legal frameworks, disclosure controls, resources and agreement of costs. If you would like to request this bespoke dataset, please contact to discuss your enquiry further. Please note, there may be a charge for this work which would be subject to our charging policy.

Deaths involving carbon monoxide and type of boiler, date of gas safety certificate or the type of housing involved

Unfortunately, we do not hold this information as this is not supplied on the death certificate.

The Health and Safety Executive may be better placed to assist with your request. The can be contacted using the following: HSE FOI Request form.

You may also wish to contact The Carbon Monoxide and Gas Safety Society using the following email: