When a paint-stripping chemical performs quickly and effectively, controlling the vapour it releases is every bit as important as the stripping result.
That was the central focus of a recent Ribble Technology installation for a customer using our Stripper HF cold-immersion paint remover. The system was designed to give the customer an effective stripping process while reducing operator exposure to volatile organic compound (VOC) vapour, particularly dichloromethane (DCM) fumes.
The readings taken during commissioning showed a clear difference.
Under the test conditions, this represented a reduction of more than 80% at the chemical surface, with the vapour being captured before it reached the operator’s working position.
Dichloromethane, also known as methylene chloride, is a highly volatile solvent used in some professional paint-stripping products. It evaporates readily at room temperature and can produce a significant amount of vapour from a relatively small volume of liquid.
DCM vapour is colourless, has a low odour and is heavier than air. This means it can accumulate at low level without giving a reliable sensory warning. Breathing it in can affect the central nervous system, causing symptoms including headache, nausea, tiredness, poor coordination and, at high concentrations, loss of consciousness. DCM is also classified as suspected of causing cancer.
For these reasons, the Health and Safety Executive’s guidance for DCM-based paint stripping places strong emphasis on preventing or adequately controlling exposure through suitable engineering controls, safe working methods, maintenance and training.
The most effective way to control vapour is to prevent it spreading into the operator’s breathing zone in the first place.
The new installation uses local exhaust ventilation (LEV) to draw vapour away from the tank and into the extraction system. Capturing the fumes close to the point at which they are released reduces the opportunity for DCM vapour to escape into the wider working area.
This is why the two monitoring positions matter. A reading of 17 ppm immediately above the chemical shows that vapour is still generated at source, as expected. However, no VOC was detected at operator level during the test. The system was therefore doing what it was designed to do: controlling the contaminant close to the tank and protecting the operator’s working position.
The result also demonstrates why general workshop ventilation alone may not be enough for a process involving DCM. Effective control depends on a system engineered around the tank, its opening, the process and the amount of vapour likely to be generated.
LEV is a critical part of the solution, but it is not the only one. Safe operation also depends on using the system correctly and maintaining every control measure.
This includes:
Stripper HF also contains hydrofluoric acid and other hazardous components, so users must follow the current Safety Data Sheet, complete a thorough COSHH assessment and have suitable emergency arrangements in place. The controls for DCM vapour form one important part of that wider safety system.
For us, a successful installation is not simply a tank and an extraction fan. It is a complete process designed around the chemical, the application, the site and the people using it.
The commissioning readings from this project provide a clear illustration of the value of that approach:
Those figures show how properly designed engineering controls can make a substantial, measurable difference at the point of use, helping the customer combine effective paint stripping with better control of DCM fumes.
If your business is reviewing an existing paint-stripping process or planning a new installation, contact Ribble Technology to discuss a system designed around your products, throughput, premises and operator-safety requirements.
Monitoring results relate to the equipment, instrument, test positions and operating conditions present during commissioning. A reading of 0 ppm means no VOC was detected by the instrument at that position; it should not be interpreted as proof of zero exposure. Spot readings are not a substitute for a suitable COSHH assessment or, where required, personal exposure monitoring by a competent occupational hygienist.
