If you’re running, or planning to install, a biomass boiler that burns waste wood, chippings or dust, you’ll need an environmental permit — and for the vast majority of installations in the woodworking and manufacturing sector, that means what’s known as a “Part B” permit. Most larger Talbott MWE installations fall squarely into this category, so we wanted to put together a clear, practical guide to what a Part B permit actually covers, what it requires of you as an operator, and why it’s worth understanding properly rather than treating it as small print.
What is a Part B environmental permit?
In England and Wales, burning waste wood in a plant with a capacity of 50kg/hour or more falls under Schedule 1, Part 2, Chapter 5, Section 5.1, Part B of the Environmental Permitting (England and Wales) Regulations 2016 — provided the waste wood doesn’t contain halogenated organic compounds or heavy metals from preservatives or coatings (different rules apply to that kind of waste). Scotland and Northern Ireland have their own equivalent regulations, regulated by SEPA and the NIEA respectively, with broadly similar principles.
Who regulates your permit depends on the scale of your plant:
- Below 1MW rated thermal input: your local authority is the regulator.
- 1MW rated thermal input or more: you fall within scope of the Medium Combustion Plant Directive (MCPD), and the Environment Agency (England) or Natural Resources Wales regulates your permit instead.
- 3 tonnes/hour or more (1 tonne/hour in Northern Ireland): you move out of Part B entirely and into Part A permitting, a different and more stringent regime.
The official reference document covering all of this is technical guidance PG5/1(21), the successor to the earlier PG1/12(13). Worth noting: at the time of writing, this guidance is formally listed as a pre-publication draft — but it’s already being actively used and cited by regulators in permits being granted right now, so it reflects current practice even though its final publication status is still pending. Always check with your regulator for the latest position.
What waste wood can legally be burned under a Part B permit?
Not all waste wood qualifies. The guidance sets out specific waste classification codes that are acceptable for Part B combustion, and in almost every case, the wood must be untreated — no chemical treatments, preservatives, or coatings:
- Waste bark and cork from wood processing and panel/furniture production
- Sawdust, shavings, cuttings, wood, particle board and veneer (this includes MDF and chipboard, provided it’s untreated) — waste classification code 03 01 05
- Waste bark and wood from pulp, paper and cardboard production
- Clean wooden packaging, including pallets
- Source-segregated, visibly clean waste wood streams, such as pallets
Critically, waste wood classified as hazardous, or originating from construction and demolition work — commonly referred to in the industry using the WRAP wood grading system as Grade B, C or D — cannot be incinerated under a Part B permit.
This is an important distinction for panel product manufacturers specifically. Offcuts and dust generated directly from your own production process — cutting, machining or sanding untreated MDF or chipboard — fall under waste classification code 03 01 05 and are Part B-eligible, provided no chemical treatment (laminates, coatings, adhesive facings) has been applied and the material stays untreated and source-segregated. Talbott MWE boilers are specifically designed to burn this kind of material as standard fuel. Where this changes is once that same material leaves the site as general waste: if it’s mixed with other waste streams during external disposal or processing, it can shift into a different classification (commonly Grade C under the WRAP system) with a different, more restrictive set of permitted uses. Dealing with your own panel product waste on-site, as fuel, keeps it within the straightforward, Part B-eligible category — one more reason on-site conversion to heat is often the simplest route for manufacturers working with MDF and chipboard.
Key operational requirements
A Part B permit isn’t just paperwork — it comes with real operational expectations, including:
- Continuous, automatic fuel feed rather than manual stop-start burning, which produces cleaner, more stable combustion
- Proper start-up procedure — the combustion chamber must be brought up to temperature before waste wood is introduced, commonly using an ancillary burner fired by natural gas, gas oil, or virgin wood, though the guidance permits other techniques provided they achieve an equivalent level of combustion control. Talbott MWE boilers use electrical heat ignition as standard for this purpose, with a virgin wood pre-start also available as an option.
- Consistent fuel handling — storing and feeding different waste wood types (offcuts, chips, dust) separately improves combustion control, since mixed fuel with variable size and moisture is much harder to burn cleanly
- Emissions monitoring at a frequency appropriate to your plant size and as required by the regulating authority, typically using accredited (MCERTs) testing providers
- Record keeping for a minimum of six years, covering inspections, maintenance, training, and emissions testing
- An environmental management system — if you’re already ISO 14001 accredited, this requirement is generally already met
Understanding emission limits
Emission limit values (ELVs) are expressed as a concentration of pollutant per volume of waste flue gas, and vary by plant size. As a general guide, for a typical mid-sized installation (90kg/hr burn rate up to 1MW thermal input), current limits include carbon monoxide at 375 mg/Nm³, dust at 90 mg/Nm³, oxides of nitrogen at 600 mg/Nm³, and total volatile organic compounds at 30 mg/Nm³. Two additional limits — for hydrogen cyanide and formaldehyde, both at 7.5 mg/Nm³ — apply specifically when melamine-faced, plywood, chipboard or fibreboard material is part of the fuel mix, which is directly relevant if chipboard dust makes up part of your waste stream.
Dust limits in particular depend heavily on the abatement technology in place: cyclones alone give variable performance depending on gas flow and dust characteristics so are typically suitable for smaller installations, while ceramic filters can achieve below 10 mg/Nm³ — comfortably within limits with the right equipment specified from the outset even for very large installations.
Plants of 1MW thermal input or more face additional requirements under the Medium Combustion Plant Directive, with compliance deadlines already in place for existing plants (over 5MW from 1 January 2025, and 1–5MW from 1 January 2030).
Why this matters when choosing your heating system
This is exactly why Talbott’s designs the MWE range around these requirements from the ground up, rather than treating compliance as an afterthought. Automatic continuous fuel feed, electrical heat ignition for start-up (with a virgin wood pre-start option available), LAMBDA control, Oxygen trim, fully modulating flue gas recirculation and full compatibility with high-performance dust abatement are built into the system design — not bolted on later. For an operator, that means a system that’s engineered to sit comfortably within Part B emission limits and operational requirements from day one, rather than a generic boiler adapted after the fact and hoping it scrapes through testing.
This makes the MWE range a particularly strong fit for manufacturers working with panel products — MDF, chipboard and particle board — where offcuts and dust generated on-site can be converted directly into heat while remaining within the straightforward, Part B-eligible waste category, rather than becoming a costlier, more complex waste stream to dispose of externally.
Given the scale of some of these installations, getting this right from the design stage — not after installation — makes the permitting process considerably more straightforward.
Practical next steps
- Engage your regulator early — local authority or Environment Agency/NRW depending on your plant’s scale — before finalising your system design, not after.
- Work with an MCERTs-accredited emissions testing provider from the outset, so monitoring requirements are built into your commissioning process.
- Keep thorough records from day one — inspections, maintenance, training, and testing all need to be retained for a minimum of six years.
- Talk to your equipment supplier about compliance, not just capacity — the right system design makes meeting these requirements dramatically easier.
Talk to us
If you’re planning a new biomass installation and want to understand how a Talbott MWE system fits within Part B requirements for your specific site, get in touch with our team — this is a conversation we have with customers every week.
Important note
This article is intended as general educational information based on current guidance (technical guidance PG5/1(21), successor to PG1/12(13)), which was in pre-publication draft status at the time of writing but is already being applied in practice by regulators. Environmental permitting requirements are specific to individual sites and installations — always confirm current requirements and your own permit conditions directly with your regulator (local authority, Environment Agency, or Natural Resources Wales) or a qualified environmental consultant before making compliance decisions.