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 Wiki
[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
The benefits of writing articles for your organisation
How to create a profile for your organisation and publish for free.
No Falls Week. The importance of safe working at height
What to expect and what is on offer to avoid accidents.
Scottish Government action to reach net-zero targets
Retrofit expert group highlight critical actions needed.
A forward thinking, inclusive global community of members.
From engineered product life-spans, to their extension.
Circular economy in the built environment
A brief description from 2021. Where are we now?
Mental Health Awareness Week with ABS
Architects Benevolent Society programme of activity.
CLC publishes domestic retrofit competency framework
Roadmap of Skills for net zero.
May 13-19: Moving more for our mental health.
Understanding is key to conservation.
Open industry engagement survey seeks responses
Institutions and the importance of engagement.
National Retrofit Hub unveils new guide
Digital Building Logbooks and Retrofit: An Introduction.
Enhancing construction site reporting efficiency
Through digitisation and the digital revolution.
Noise in the built environment
BSRIA guide TG 20/2021.
17,000 people suffer conditions as a result of exposure to excessive noise at work.
Turning down the noise: Auditory health
A pervasive risk with far-reaching consequences.
Getting the most out of heat pumps and heating
How heat pumps work and how they work best.
Electrotechnical excellence, now open for entries.