Smoke Clearance and TExT Testing – Spray Booth Performance and Safety

Beta offers a wide range of services relating to the performance and safety of spray booths, and with 20 years of experience behind us, our expert engineers are highly knowledgeable of the hazards posed to human health by poorly maintained equipment or careless/outdated working practices. Exposure to isocyanate is a particularly tangible danger for those working in the spray booth industry, and one that we test extensively for using our smoke clearance testing and overarching TExT tests. More detail about the nature of these tests, and why they’re so important, is laid out below.

Dangers of isocyanate

Isocyanate exposure is one of the most crucial safety concerns surrounding spray booths. Isocyanate is an odourless, tasteless, colourless organic compound (vapour). Many paint products and lacquers contain isocyanate and contrary to popular belief, it can often be found in many water-based products too. Exposure to isocyanate can lead to occupational asthma and according to the HSE, vehicle paint sprayers are about 80 times more likely to contract this than the average worker.

People become sensitised to isocyanate at different rates, which means that no level of exposure is safe. Therefore, it is vital that spray booth operators and other personnel in the area are protected from isocyanate. When in a spray booth, operators must wear air-fed Respiratory Protective Equipment (RPE) if using isocyanate based products. In addition to this, the air supply must be tested every 3 months to ensure that it is safe for the operators to breathe. The cabin must be under negative pressure at all times to prevent the escape of any isocyanates, and the cabin and ducting must be fully sealed and tested at least every 14 months.


Smoke clearance testing

Smoke is used to replicate, as closely as possible, how isocyanate vapour behaves in a spray booth cabin and ducting. Beta offers smoke (mist) clearance testing to identify how long it takes for a spray booth to purge itself of isocyanate once spraying has ceased, along with detection of leakage.

One of the mandatory measures of this procedure is that a clearance poster must be displayed clearly on each personnel door of the spray booth. However, in our experience, we have found that the clearance poster alone realistically does not provide an adequate solution to inform all personnel of when it is safe to enter the spray booth cabin without RPE. Essentially, a poster alone is easily ignored or overlooked, either accidentally or intentionally.

Therefore, we also recommend that specialist systems are installed to provide a traffic light indication of when it is safe to enter the spray booth. Beta offers various systems that can be linked to the spray gun to indicate (using this traffic light system) when the spray booth cabin is safe to enter without RPE. This enables a more reliable and effective control measure for employers to prevent exposure to isocyanate, protecting the health of their employees.

As mentioned above, it is also vital for employers to prevent positive pressure within the cabin, as this can leak isocyanate from inside. To this end, Beta offers a range of solutions to shut down or alarm the system to ensure a spray booth does not continue to operate in positive pressure. We recommend all customers have a shut-down alarm fitted as an essential minimum control.


Thorough Examination and Testing (TExT)

The TExT test is a comprehensive examination of the spray booth system. This incorporates the previous LEV (Local Exhaust Ventilation) test, along with some elements of COSHH, Workplace safety regulations 1997 and DSEAR 2002 regulations. The smoke clearance test outlined above is a key part of the overarching TExT test.

Regularly, we receive requests to undertake a smoke test in isolation, to enable a clearance poster to be produced. However, it is a mandatory requirement for the spray booth to undergo a TExT every 14 months. This is also an insurance requirement.

At Beta, our engineers are trained to P601 standard (Competence in Thorough Examination and Testing of LEV systems) to ensure competence to undertake the TExT. During the test, we will inspect all aspects of the systems and make recommendations where necessary. Common issues we identify include:

  • cracked light and door glasses
  • blocked filters
  • unsuitable electrical components
  • open paint tins
  • other trip hazards

A good understanding of the test can enable employers to keep their spray booth in the optimum condition, helping them to avoid unexpected remedial repairs and down time. When undertaken at the time of a service, our customers have the benefit of reduced test costs and the potential for faults or potential failings to be rectified before the test is carried out.


Competence/why choose Beta Group

All services undertaken by Beta are completed by our own, highly qualified engineers. We ensure that our staff are trained to the very latest standards, and take care to comply fully with the Gas Safe Register. In the course of our services, we sometimes come across gas systems that have not been tested to the standards of the Gas Sage Register, or have been maintained by someone unqualified. This is illegal, since the law says that no gas appliance can be serviced by by a non-gas safe person. Permitting burner components and parts to be swapped or adjusted by someone not qualified to do so could result in void insurance or criminal prosecution. By the Gas Safe Register’s standards, a person is only competent if their accreditations are valid, applicable and in date.

Though the law is clear on this point, we understand that in a broader sense, legislation and guidance can be difficult to understand in the spray booth industries. This is why Beta experts are always on hand to offer professional guidance and advice, ensuring that our customers are kept up to date with the changes and requirements of the current standards. Should you have any issues, please contact our team on 01706 878330 for more information.

Alongside this consultation and advice, we’re maintaining our focus on providing you with market-leading products and services around air filtration, spray booths maintenance and building services. Feel free to give us a call on 01706 878330.


  • gas-safe
  • safe contractor approved
  • BESA
  • NBRA
  • ABP
  • chamber of commerce
  • CHAS Transparent