Incinerator Bottom Ash – Preparation, Testing and Monitoring

SOCOTEC boasts one of the UK’s leading laboratories for the energy & waste sector. As such, we offer an extensive range of accredited preparation, sampling and testing for power generators and waste management companies. As part of our portfolio of services, we provide Incinerator Bottom Ash (IBA) preparation, testing and analysis.

Why Test Incinerator Bottom Ash?

IBA is the ash that is left over after waste has been burnt in an incinerator. Depending on the composition of the waste, IBA can contain a number of materials including metals, rubble and concrete. Approximately 1 million tonnes of IBA are produced throughout England and Wales each year (ESAUK), while larger materials can be reused, there is a duty of care for the site operator to characterise the rest of the ash as hazardous or non-hazardous before choosing a waste route. 


Preparing Incinerator Bottom Ash

At SOCOTEC’s sample preparation facility, the IBA samples are dried, if required. Once dry, all the obvious metals, both ferrous and non-ferrous, are removed. The remaining sample is then processed through a series of crushing stages, with further metal removal when in a finely ground stage. At this point, the total metals are then recorded. The sample submitted to the laboratory for analysis is ground to a fine powder. By carefully following the correct preparation procedure, the sample is deemed as being representative of the bulk sample received from site.


Testing and Analysis for Incinerator Bottom Ash

Our environmental chemistry laboratory has vast experience in testing IBA and has even developed a methodology to reduce turnaround times to five days.

To test the metals for IBA, we typically digest the ash with aqua regia and analyse the sample using ICPMS or ICPOES. We understand your challenges and therefore stress the importance of getting a homogeneous sample, to reduce the risk of re-sampling which can be costly both in terms of money and time. In analysing the metals, we can determine how to classify the IBA, as either hazardous or non-hazardous, using the ESA protocol guidelines.


Monitoring Incinerator Bottom Ash

Monitoring IBA is a requirement for all energy from waste incinerators that have an Environment Agency permit. However, depending on the suite of analysis required, the frequency of test can vary, being as often as monthly to as infrequent as quarterly.

SOCOTEC can offer ongoing monitoring and testing for IBA using our accredited laboratories. The analysis suite includes:

  • Dioxins & furans, including total petroleum hydrocarbons (TPH)
  • Heavy metals
  • pH, alkali reserve and cyanides


What about APC?

Air Pollution Control (APC) residue is a by-product of cleaning flue gases following the combustion process, where waste gases essentially go further up the chimney. These are often classed as hazardous waste and therefore it is a permit requirement to test APC. SOCOTEC can monitor your APC residue, with our scope of tests including dioxins & furans, as well as heavy metals. We offer regular, bi-annual monitoring and testing to keep you compliant with your permit.  

Also, if your site changes its recycling route, then we can offer the necessary WAC analysis. This includes a standard WAC test, with a five day turnaround on results.


Why Choose SOCOTEC?

Testing your IBA with SOCOTEC can offer the following benefits:

  • Keeps you compliant - Helps to keep you compliant with your environmental permit
  • Choosing the most effective waste route - Determines what hazard the material contains, in accordance with the ESA protocol, so you could choose the most efficient and effective waste route
  • Reducing storage space - With our fast turnaround, you can ensure that the ash is removed from site sooner, rather than later, saving storage space and minimising costs
  • Saving money - Being confident in the characterisation of the ash ensures that you make the right disposal choices, which could save you money
  • Data precision - Our robust methodology ensures, minimising your risk and helping peace of mind


Find Out More About IBA

SOCOTEC takes a partnership approach to its testing, inspection and compliance services. We are keen to understand your challenges and work with you to create the best solution. Our team of UK leading experts can offer solutions at every stage of your IBA and APC testing and analysis. For more information, or some free advice, please contact 0845 603 2112 or