Compressed air systems and tools

Compressed air bottles

Compressed air bottles must be fitted with:

  • Rating plate.
  • Safety valve with relief device.
  • Pressure gauge (manometer) marked with a red line to show the maximum permitted working pressure.
  • Drainage nozzle for condensate in reservoir.

Bottles must be positioned so as not to be subject to collision, knocks or blows.

An expert must inspect compressed air bottles internally and externally every four years, ensuring that the pressure in bar (ato) times the volume in litres is greater than 200.

Compressed air tools

Machines and tools operated using compressed air are subject to the general provisions for machine protection.

Compressed air-driven tools/devices should be used in place of low-voltage devices in tanks, wet rooms, on wet concrete and elsewhere where there is strong leakage to earth.

Compressed air tools often cause a lot of noise and dust. Therefore, acquire the tool that makes the least possible noise, and use it at the lowest possible pressure. Apply special nozzles to the tool in order to reduce the spread of noise and dust, e.g. a cover or bellows and possibly a filter. If it is not possible to reduce the noise or dust load sufficiently, personal protective equipment must be used.

Minors under 18 must initially not work with rotary compressed air tools, compressed air hammers and chisels and sandblasting, unless this is taking place in connection with training which aims to give them skills (e.g. as apprentices), and unless they are to receive the proper instruction. However, they may work with these if they receive proper instruction.

There must be usage instructions in Danish which indicate how to set up, operate and maintain the tool in connection with work.

Rotary compressed air tools

Grinding wheel tools must be secured to prevent the disc rotating at too high a speed, including in the case of air being connected at a pressure higher than prescribed.

Compressed air hammers

When using compressed air hammers, it is necessary to ensure that vibration in the building will not cause a hazard.

Drilling hammers

Hazardous concentrations of dust, e.g. quartz dust, may be given off when chiselling in concrete and masonry. Here, it is necessary to limit the spread of dust to the surrounding area by means of dust extraction or by spraying water, if it is not possible to extract the dust. It is necessary to remove dust in a way which does not spread dust – e.g. by means of dust extraction.

Drilling hammers vibrate extensively. As far as possible, plan the work so that you use remotely controlled tools or so that handheld tools can be supported mechanically. Vibration-damped tools should be selected when acquiring tools.
It is possible to damp vibration in existing tools by using handles made of shock-absorbent materials.

You must always wear eye protection, and normally ear defenders and respiratory protection as well, when working with compressed air hammers, and it may also be necessary to wear safety footwear.

Sandblasting

Sandblasting is understand to include blasting with natural sand, steel sand, cast iron sand, baking powder, steel balls, corundum, glass and similar.

Sandblasting with natural sand should be avoided as this contains quartz. Quartz is particularly hazardous to health and poses a risk of silicosis and cancer.

As far as possible, limit the spread of dust during sandblasting outdoors by means of a tarpaulin or similar. Put up warning signs and make sure that sandblasting only takes place in areas where it will not cause inconvenience to others.
The operating arrangement must have a hold-down handle (dead man’s control). In the case of long hoses (above 40 m), it is advised that the opening function be controlled electrically. Unified air control is not permitted.

When working at low temperatures, the hold-down handle of the ejector must be secured to prevent incorrect function due to frost in condensate. This can be done using anti-freeze and dosing equipment.

  • Sandblasters must use respiratory protection with an air supply either as a hood which covers the head, neck and shoulders, or as a full mask plus a hood. The air supply to respiratory protection must be provided from a system with an oil separator and possibly also a heating or cooling unit.
  • Sandblasters and all other people in the sandblasting area, even for a short time, must wear special dust-repellent workwear such as a close-fitting overalls, tall boots and working gloves with long cuffs.
  • Ear defenders are normally necessary.
  • Workwear and personal protective equipment must be kept separate from everyday clothes and must not be taken into eating areas.

Remove used sand as quickly as possible. Cleaning using compressed air is not permitted. Brushing and shovelling may be carried out once the sand has been wetted. The sand may only be reused following special cleaning. Respiratory protection must be used when cleaning.

Before starting work on renovating façades, the municipal authorities must give permission for the work.

Waste must be removed in accordance with the rules laid down by the Ministry for Energy and the Environment.

It is possible to increase the cleaning effect by adding water. Wet sandblasting is not as hazardous to health as dry sandblasting as the quantity of dust in the air here is just 1/10. The sand must be removed while it is wet.

High-pressure cleaning

High-pressure systems with a maximum pressure in excess of 800 bar pose particular hazards, and these must never be used handheld due to the cutting ability of the jet and its powerful kickback.

When working with high-pressure cleaners with pressures in excess of 25 bar, or where the product rating (the maximum pressure in bar times the number of litres per minute) is in excess of 10 000, it is necessary to make sure that:

  • There is no-one else in the work area.
  • You do not spray onto electrical installations.
  • You have a non-slip foothold.
  • You have a free, unhindered working area around you. (Working on ladders is not permitted.)

If you are working for more than half an hour, you must have a shoulder strap or similar which can relieve the pressure of the hands on the spray nozzle.

Hazards during use:

  • The jet acts as a cutting tool on both materials and people (injuries are deep and serious, even though the lesions do not appear to be much).
  • The jet may be thrown back from hollows and curved surfaces.
  • Substances which are toxic or hazardous to health may be spread in the form of a mist.
  • Hoses and nozzles may vibrate like compressed air tools (causing white fingers).

Use the wind direction on the site to remove impurities. It is generally necessary to use personal protective equipment.
Minors under 18 must initially not carry out high-pressure cleaning at a working pressure in excess of 70 bar (7 MPa) unless this work is taking place in connection with training which aims to give them skills (e.g. as apprentices), and unless they receive the proper instruction.

There must be usage instructions in Danish which indicate how to set up, operate and maintain the machine in connection with work.

High-pressure cutting

Never use high-pressure cutters handheld if the pressure is in excess of 800 bar. This is hazardous due to the cutting ability and powerful kickback of the jet.

Nozzles must be secured in special tools.

The cutting area must be inaccessible due to the power of penetration. The working field of the jet must be shielded according to the rules for machine protection.

Mist and noise may occur as with high-pressure cleaning, so respiratory protection and ear defenders may be necessary.

Minors under 18 must not carry out high-pressure cutting unless this is taking place in connection with training which aims to give them skills (e.g. as apprentices), and only if they have received the proper instruction.

There must be usage instructions in Danish which indicate how to set up, operate and maintain the machine in connection with work.