Dust created during thermal spraying processes can give rise to a number of potential hazards to equipment operators, unless correctly addressed. It is now mandatory within the law to undertake a proper risk assessment when considering new plant to ensure that these risks are minimised.
Issues to be condsidered include:
For many years the use and handling of flammable gases in industry has been tightly controlled by rules that dictate what is acceptable practice in 'zoned areas'.
There are also many dust types which are potentially explosive when suspended in air, but it was only recently that the regulations contained in the ATEX directive came into force to lay down acceptable safe practice for dust handling.
The new regulations clearly state that operators of equipment that generates and captures dust must be able to prove that, through the design and deployment of the equipment, the explosion risks have been assessed, quantified and minimised.
Minimisation of the explosion risks means that where a risk has been identified, acceptable measures have been taken to avoid ignition and to have a safe pressure venting system in place, should an explosion occur.
Many of the airborne dusts created by thermal spraying processes can be very hazardous to health if inhaled. It is therefore extremely important when installing thermal spraying systems that adequate dust control measures are incorporated.
Ideally the process should be carried out in an enclosure to prevent escape of the dust and noise into the work area. A dust and filtration system should be provided to allow the harmful dust to be captured safely.
The other function of the thermal spraying enclosure is to reduce the noise to acceptable levels. Typically, noise levels between 120 and 130 dBA can be generated whilst spraying and, in order to comply with COSHHH regulations, this needs to be reduced below 80 dBA at 1 metre.
The greatest hazard to personnel is the thermal spraying process itself. Severe burns or blindness can result if operators are not suitably protected and, in addition, crushing injuries could occur if robots are not made safe, and even asphyxiation could result from build-up of the process gasses if inadequately vented.