Oil disposal in industry & with PCBs: Is incineration the solution?

In many industrial sectors, used oil is still incinerated – a quick and definitive way of getting rid of the material. When it comes to transformer insulating oils, however, a closer look is worthwhile, because these oils are high-value and critical to safety. Whenever transformer oil is replaced during maintenance or refurbishment, one central question arises: dispose of it or regenerate it? 

When is incineration a good choice for oil disposal? 

Incineration is a valid option when the insulating oil in a transformer is significantly contaminated with PCBs (polychlorinated biphenyls). For heavily PCB-contaminated transformer oil, strict regulations apply. Two treatment methods are available:

1. Decontamination (e.g. dechlorination), or 
2. Destruction in authorised facilities – this includes incineration in high-temperature furnaces.  

Which method must be chosen depends on the PCBs content and the applicable legal framework. Both in the EU and in the United Kingdom, clear legal thresholds apply: 

• All volumes of insulating oil containing PCBs above 50 ml and with a concentration greater than 0.005% (50 ppm) must be destroyed or irreversibly transformed (EU Regulation on Persistent Organic Pollutants – POPs Regulation (EU) 2019/1021). 
  
• A clear deadline has been set: this must be completed by the end of 2025.

(Source: European Commission – PCBs and PCTs)

This type of oil disposal also means that the raw material is lost forever – and incineration generates additional CO₂ emissions.

For insulating oils that are not, or only lightly, contaminated with PCBs, this is rarely the optimal solution. For transformer oil without PCB-contamination, there are several alternatives.

Read more on this topic:

• PCBs in transformers: Why it is high time to act

Considering oil treatment and oil regeneration (recycling) instead of  transformer oil disposal 

If there is no PCB-contamination, transformer oil does not have to be destroyed – it can be processed (reconditioned) or even regenerated (recycled).

Typical steps in improving the quality of transformer oil include:

• Filtration and drying – removes particles and water from the insulating oil 
• Degassing – stabilises the dielectric strength of the insulating oil 
• Adsorption – reduces ageing products and acids in the insulating oil
• Regeneration or recycling – restores the insulating oil to a like-new condition in line with IEC 60296 

During regeneration or recycling, the insulating oil is processed to meet the requirements of IEC 60296 (the standard defining the quality criteria for new and recycled mineral insulating oils) and is thus restored to a like-new virgin oil condition.

For purchasing managers, this means: once the standard is met, regenerated insulating oil is technically equivalent to new insulating oil according to IEC 60296 – and fully fit for use.

Both oil reconditioning and regeneration can be carried out in specialised stationary plants or with mobile equipment on site – often without long downtimes.

More to read:

• Minimising effort and costs: Benefits of mobile regeneration of transformer oil

Avoid oil disposal: keep transformer oils in the cycle for as long as possible

Insulating oils are valuable materials – and at the same time a lever for greater sustainability in the energy sector.

Those who keep transformer oils within the cycle reduce procurement costs, cut down on waste volumes and actively contribute to conserving valuable resources. Modern regeneration processes make it possible to restore insulating oil to a like-new condition multiple times, without compromising technical quality.

The result: lower feedstock consumption, reduced environmental impact and a clear alignment with corporate objectives as well as the goals of the circular economy.

Learn more in the interview:

• Waste management company: Dispose of or save used transformer oil?
  
  
      

Conclusion: Check whether your transformer oil really needs to be disposed of 

Incineration only makes sense where destruction is legally or technically required – for example, in the case of PCB-contamination without a practicable decontamination option. In all other cases, regeneration to insulating oil in like-new condition is an equivalent but more resource-efficient solution. It meets the same standards as new oil (according to IEC 60296), saves costs and supports a sustainable procurement strategy. 

Further reading:  

• How cost-efficient and sustainable is recycling transformer oil?

Practical tips for insulating oil disposal

Before arranging oil disposal, the following points should be checked in advance: 

• Heavily aged or contaminated transformer oil:  
  Before making a decision, a laboratory analysis is recommended – for example, Dissolved Gas Analysis (DGA), determination of water content and acid number, as well as the PCB content. The results of this analysis will show whether incineration is necessary or whether regeneration of the transformer oil is economically and technically viable.
• Transport and permits:  
  The transport of insulating oils is subject to hazardous goods regulations and may only be carried out by authorised companies. Complete documentation is mandatory.
• PCB-containing transformer oil:
  • Inventory and labelling: Oils containing PCBs must be inventoried and labelled in accordance with legal requirements.
  • Disposal routes: Depending on the PCB content, either decontamination (e.g. dechlorination) or destruction in authorised facilities is required – incineration is only one of the possible methods.