1. What is PG5/2(25)?
PG5/2(25) is the current UK process guidance for crematoria. It sets out the technical framework used by regulators when assessing crematorium installations and permits, including emission limits, monitoring, control measures and Best Available Techniques.
The guidance applies to cremation installations across the United Kingdom, subject to the applicable regulatory framework in each nation and the conditions of the individual environmental permit.
PG5/2(25) is not simply a “filter rule”. It affects how the cremator, flue-gas treatment system, monitoring, controls and operating procedures are considered as a complete installation.
2. The key date: 4 December 2029
The most important date for operators of existing crematoria is 4 December 2029.
This does not mean every crematorium will need a complete new cremator. It does mean that operators should assess the technical capability of their current equipment well before the deadline.
New cremator
A new cremator must be engineered around the current requirements and the relevant site permit from the outset.
Replacement cremator
Where an existing cremator is replaced, the replacement should be treated as a modern installation and designed around the applicable current requirements.
Substantial change or retrofit
Major technical changes can affect how the current standards are applied to the modified parts of an installation. Examples may include replacement of the principal cremation unit or major changes to the flue-gas treatment system.
The final interpretation for a specific site depends on the regulator and the site permit. CFI Systems provides engineering and technical support, not regulatory certification.
3. Mercury abatement becomes a central design question
PG5/2(25) places strong emphasis on flue-gas treatment and mercury abatement. For many existing crematoria, this means the 2029 strategy must look beyond the cremator itself.
Typical dry flue-gas treatment architectures can combine gas cooling, sodium bicarbonate or lime, activated carbon, a baghouse or ceramic filter, extraction and instrumentation. The correct architecture depends on gas temperature, flow, pollutant loading, available space and the existing installation.
Mercury control should therefore be considered together with reagent choice, temperature window, mixing, filter performance, residue handling and the interaction between the cremator and the downstream treatment line.
4. Emission limits: what changes for existing cremators?
The current guidance tightens several emission values for new cremators. Existing cremators transition to the new-cremator values from 4 December 2029.
| Pollutant | Existing cremator | New cremator / 2029 target for existing |
|---|---|---|
| Particulate matter | 10 mg/Nm³ | 5 mg/Nm³ |
| HCl | 30 mg/Nm³ | 20 mg/Nm³ |
| TOC | 20 mg/Nm³ | 10 mg/Nm³ |
| Mercury (Hg) | 50 µg/Nm³ | 30 µg/Nm³ |
| NOx | 200 mg/Nm³ at the four-year implementation point | |
| PCDD/F | 0.1 ng/Nm³ for cremators with flue-gas treatment | |
These figures show why a 2029 programme should start with measurements and a technical assessment rather than with a product decision.
5. Retrofit or replace?
There is no single answer for every crematorium. The correct strategy depends on the age and condition of the cremator, the current abatement system, available space, electrical infrastructure, operating profile, number of cremations, maintenance history and long-term energy strategy.
Optimise
Combustion tuning, process control, instrumentation, automation and operating parameters.
Retrofit
Flue-gas treatment, mercury abatement, NOx reduction, filtration, automation and heat recovery.
Replace
New gas, hybrid or electric cremator with a complete modern abatement and control system.
Keeping technically sound equipment can be economically sensible. Replacing equipment that can no longer achieve the required performance can be equally sensible. The decision should follow the assessment, not precede it.
6. Mercury abatement alone is not the whole 2029 question
Conventional dry reagent systems are highly relevant for mercury, acid gases and particulate matter, but they do not by themselves solve every emissions issue.
NOx must also be considered. Depending on the existing cremator, the strategy may include combustion optimisation, process-control improvements and, where necessary, a dedicated NOx-reduction technology such as SNCR or another technically appropriate solution.
This is why CFI Systems approaches the 2029 problem as a complete thermal-process question: cremator performance, secondary combustion, air management, gas temperature, filtration, extraction, monitoring and automation all influence the result.
7. The 2029 transition can also create a heat-recovery opportunity
Flue gases often need to be cooled before downstream treatment. Where the energy balance and local demand justify it, this can create an opportunity to recover useful thermal energy.
Potential uses include building heating, domestic hot water, adjacent facilities or a local heat network. The opportunity should be studied without compromising the flue-gas treatment temperature window or cremator operation.
A major retrofit programme can therefore be more than a compliance project. It can also be an opportunity to improve energy performance and reduce wasted heat.
8. How CFI Systems can support UK crematoria
CFI Systems combines nearly 20 years of technical experience in cremation, combustion and flue-gas treatment with an engineering approach covering the complete installation.
Existing installation assessment
Measurements, equipment review, pressure losses, combustion, filtration, automation and operating constraints.
PG5/2(25) upgrade strategy
Technical scenarios for optimisation, retrofit, abatement or replacement.
Flue-gas treatment
Cooling, reagent dosing, mercury abatement, filtration, extraction and monitoring.
Cremator replacement
Gas, hybrid and electric cremator projects integrated with the downstream treatment line.
Regulatory note: CFI Systems provides engineering and technical support. Environmental permit requirements and final regulatory interpretation remain the responsibility of the relevant regulator and the applicable site permit.
Frequently asked questions
What is PG5/2(25)?
PG5/2(25) is the current UK process guidance for crematoria. It addresses emission limits, monitoring, control measures and Best Available Techniques.
What changes on 4 December 2029?
Existing cremators must comply from that date with the emission limit values applicable to new cremators under the current guidance.
Does every crematorium need a new cremator?
No. Some sites may be suitable for optimisation or retrofit, while others may require partial or complete replacement. The correct decision depends on the condition and technical capability of the existing installation.
Is mercury abatement the only issue?
No. Mercury is a major part of the discussion, but particulate matter, acid gases, TOC, NOx, dioxins/furans, monitoring and process control also need to be considered.
Can CFI Systems support a UK project?
Yes. CFI Systems can assess the existing installation and develop technical scenarios covering cremator performance, filtration, mercury abatement, retrofit, automation, heat recovery and replacement.
The earlier the existing installation is characterised, the more options remain available for phasing, budgeting and minimising operational disruption.