Guidance

Monitoring stack emissions: low risk MCPs and specified generators

How to monitor emissions from low risk medium combustion plants (MCPs) and specified generators (SGs).

• From: Environment Agency
• Published: 16 February 2021
• Last updated: 20 January 2026
  Show all updates

  1. 20 January 2026

     The scope of the guidance has been extended to include MCPs and SGs with simple bespoke permits. For continuous monitoring, the use of MCERTS certified low risk plant monitors has been added. Only MCERTS certified HEMS with a suitable certification range may be used for periodic monitoring.

  2. 4 June 2024

     Clarified in section 10 'If you are following the monitoring approach in this guidance, you must not exceed a expanded measurement uncertainty of ±20% for nitrogen oxides.' and 'When assessing compliance for nitrogen oxides, we will use a fixed expanded measurement uncertainty of ±20%.

  3. 20 March 2024

     Removed reference to MCPD Help and replaced with MCP Returns.

  4. 12 July 2022

     Certified range multiplier changed from 2.5 to 6.5.

  5. 16 February 2021

     First published.

Applies to England

Documents

Monitoring stack emissions: low risk MCPs and specified generators

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Reporting sulphur dioxide emissions based on fuel sulphur content

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Details

This guidance provides a standardised approach to monitoring stack gas emissions from low risk plants regulated under the:

• Medium Combustion Plant Directive (MCPD) 2015/2193/EU Directive on the limitation of certain pollutants into the air from medium combustion plant
• Specified Generator Regulations (SGRs) EPR 2018 Schedule 25B 2 (1) – Specified Generators

This guidance is for operators of:

• MCPs and SGs with standard rules and simple bespoke permits
• other low risk MCPs and SGs
• MCP installations where the Environment Agency has agreed to the use of this standard

This guidance also provides an approach for calculating the sulphur dioxide (SO₂) content of stack gas emitted by MCPs.