Construction solvents: Spraying

Spraying products that contain solvents such as glues, paints and paint strippers can produce very high levels of airborne exposure to solvents.

What you should know

Solvents can produce narcotic effects like dizziness and tiredness. High concentrations increase the severity of these effects. Unconsciousness and death can even occur. This means it is very important to have the right controls in place and to make sure they are properly used. This page tells you how to control this risk and why. You also need to be aware of the general information on construction solvents.

What you must do

Follow the Assess, Control and Review model. Pay particular attention to the following things:

Assess

Identify and assess: The risks from spraying solvent containing materials vary. Risks can be reduced by choosing other methods of application, such as brushes/rollers to apply paint or using spatulas to apply glues.  You need to consider the factors outlined in the general information on solvents . You are generally at lower risk if you are spraying low solvent products for short periods in an open / well-ventilated space. Spraying tasks involving high solvent products, especially in poorly ventilated work areas, can produce very high airborne exposure to solvents. You are particularly at risk if spraying highly volatile solvents Dichloromethane (DCM) in small / enclosed spaces. Seek specialist help if you are unsure.

Control

Follow the precautions for controlling general solvent risks . In addition, you should also consider the issues below. These are guidelines only. The range of solvent containing products available means that you must decide on the specific controls you need based upon your assessment of the risks. Take specialist help if you unsure about this.

• Spray equipment - choose the correct equipment for the work. Be aware of issues associated with different types of spray equipment. 'Conventional' spraying uses compressed air to atomise the product. This can create quite a lot of overspray / mist in the air that can travel significant distances. You may improve this by using high-volume low-pressure (HVLP) spray guns. Alternatively, airless spraying forces products such as paint through a nozzle under high pressure. There is less overspray / mist travel with this method. However, there is risk of injecting the product into the skin if the spray tip is not properly guarded. Use the correct tip sizes and pressure.
• Ventilation - always ensure good ventilation.  For some highly volatile and/or very hazardous solvents, such as DCM, general natural ventilation is not sufficient to disperse the airborne solvent.  In these circumstances you will need mechanical ventilation, or local exhaust ventilation (LEV) to prevent build-up of airborne solvent to a dangerous level. Make sure any extracted air is discharged to a safe place.
• Segregation - keep all non-essential people away from the work area until the risk has been minimised. You may need to barrier off the area. Consider wind speed and direction if working outside. This can cause spray / vapour to drift large distances.
• Respiratory Protective Equipment (RPE) - you are likely to need RPE in most instances. The level of protection will vary with the risk. Below are some examples that may be suitable for different situations:
  • half-face mask respirator with an A1P3 filter(s) for intermittently spraying lower solvent products over a shift with little general ventilation
  • powered (fan-assisted) respirator with a visor and A2P3 filter(s) for longer tasks like spraying lower solvent products most of a full shift in one location
  • constant flow air-fed breathing apparatus (CFABA) with a low flow indicator for spraying products containing high levels of solvent, especially those containing highly toxic and/or volatile solvents such as DCM, particularly in an enclosed space. Make sure the breathing air is uncontaminated and meets 'minimum flow conditions' in terms of tubing length / internal bore and air pressure.

These are examples only. You must get the correct RPE for the work you are doing. Check with your supplier if you are unsure.

• Work practices - good spraying technique is important to limit overspray and bounce back. Improve visibility by using tear-off visor protectors if needed. Keep RPE on until you have left the work area or the area is clear. Cleaning the spray gun is another potential source of significant exposure if the gun is cleaned with thinner and sprayed through without proper controls.
• Confined spaces - your work may mean that solvent vapours could build up to dangerous levels. You will need special precautions if you are working in a confined space.
• Fire and explosion - sufficient amounts of solvent / vapours create a fire and explosion risk. You may also need special precautions for these risks.

Review

Supervise: Ensure equipment is properly used and RPE is worn correctly. Anyone using tight fitting RPE also needs to be clean-shaven and face-fit tested.

Maintain: Make sure all the controls are properly maintained.

Monitor: You are likely to need exposure monitoring where the risk is high to ensure your controls are working properly. Be clear about what you are going to measure and how you will use the information.