Coal tar
Contents |
[edit] Introduction
Coal tar is a by-product derived from coal during the manufacture of domestic town gas. It was commonly used in the UK as a binding agent for aggregate in the construction of highways, car parks and paving until the 1980's when North Sea gas was introduced and town gas works closed. Bitumen was then adopted as the binding agent for macadam and top dressings.
Coal tar can have a high concentration of carcinogenic material such as benzo(a)pyrene and many other polynuclear aromatic hydrocarbines (PAH’s). This means it is potentially hazardous to human health (a potential cause of cancer) particularly when mixed with other materials such as asphalt waste.
[edit] Disposal
Because of this risk to human health, it is obligatory to carry out tests before digging up such material. These tests will determine:
- The identity and composition of any PAH’S.
- Whether it is to be classified as waste coming under the Hazardous Waste Regulations 2005.
- Whether the material can be re-used or has to be sent to a specially designated landfill site for hazardous waste.
Needless to say there are substantial financial implications resting on the outcome of such tests. It is strongly recommended that early discussions are held with the Environmental Agency and local planning authority following the removal and testing of cores to establish a strategy for maximum re-use and to avoid disposal to landfill.
[edit] Re-use
If the Environmental Agency agrees to its re-use it can be re-processed at a registered and approved facility as aggregate in a bitumen bound material such as a cold mix asphalt. The treated asphalt waste containing coal tar will have to meet the Specification for Highways Works 900 Series (clause 948) and 800 series (clause 810 to 880).
[edit] Related articles on Designing Buildings
- Coal.
- COSHH.
- Deleterious materials.
- Health and safety.
- Pitch.
- The architectural use of wood and coal tar in England.
[edit] External references.
- CM Magazine. CPD Coal tar, by Russell Cobyn, May 2013 edition.
- Hazardous Waste Regulations 2005.
- Government, How to classify different types of waste.
Featured articles and news
Future Homes Standard Essentials launched
Future Homes Hub launches new campaign to help the homebuilding sector prepare for the implementation of new building standards.
Building Safety recap February, 2026
Our regular run-down of key building safety related events of the month.
Planning reform: draft NPPF and industry responses.
Last chance to comment on proposed changes to the NPPF.
A Regency palace of colour and sensation. Book review.
Delayed, derailed and devalued
How the UK’s planning crisis is undermining British manufacturing.
How much does it cost to build a house?
A brief run down of key considerations from a London based practice.
The need for a National construction careers campaign
Highlighted by CIOB to cut unemployment, reduce skills gap and deliver on housing and infrastructure ambitions.
AI-Driven automation; reducing time, enhancing compliance
Sustainability; not just compliance but rethinking design, material selection, and the supply chains to support them.
Climate Resilience and Adaptation In the Built Environment
New CIOB Technical Information Sheet by Colin Booth, Professor of Smart and Sustainable Infrastructure.
Turning Enquiries into Profitable Construction Projects
Founder of Develop Coaching and author of Building Your Future; Greg Wilkes shares his insights.
IHBC Signpost: Poetry from concrete
Scotland’s fascinating historic concrete and brutalist architecture with the Engine Shed.
Demonstrating that apprenticeships work for business, people and Scotland’s economy.
Scottish parents prioritise construction and apprenticeships
CIOB data released for Scottish Apprenticeship Week shows construction as top potential career path.
From a Green to a White Paper and the proposal of a General Safety Requirement for construction products.
Creativity, conservation and craft at Barley Studio. Book review.
The challenge as PFI agreements come to an end
How construction deals with inherited assets built under long-term contracts.
Skills plan for engineering and building services
Comprehensive industry report highlights persistent skills challenges across the sector.
Choosing the right design team for a D&B Contract
An architect explains the nature and needs of working within this common procurement route.
Statement from the Interim Chief Construction Advisor
Thouria Istephan; Architect and inquiry panel member outlines ongoing work, priorities and next steps.