HAND-ARM VIBRATIONS

• 09.01 - Causes of health problems
  
• 09.02 - Detection of problems
  
• 09.03 - Preventive and safety measures
  
  

Discription of chapter

The specific chapter, deals with issues concerning a number of hazardous situations originating from mechanical vibrations, as well as ways of detecting, preventing and facing health problems associated with exposure to hand – arm vibrations.

The objective of this chapter is to familiarize all personnel involved in occupational health and safety at metal processing installations, with hand-arm vibrations, in terms of human body strain, as well as preventive and safety measures that can be implemented at workplace.

Cause of health problems.

Frequent exposure to high levels of vibration may lead to permanent injuries. This is most likely to happen if contact with a vibrating tool is part of daily routine work.

Although occasional exposure rarely results in an injury, it should be definitely avoided by people suffering from Raynaud syndrome.

Symptoms: Frequent exposure to vibrations may cause irreversible damage to hands and arms, a condition, which is known as hand-arm vibration syndrome. The effects may concern:

• Blood circulation (white finger syndrome)
  
• Sensor neural damage
  
• Muscles, bones or joints
  

Health problems may be painful, for example:

• Painful white finger seizures (stimulated by exposure to either high or low temperature conditions)
  
• Loss of feeling and temperature sense
  
• Tingle and pain
  
• Inability to hold an object tight
  
• Loss of hand efficiency
  

The time that symptoms take to appear depends on a number of factors including the intensity of hand vibration and exposure period. People exposed to vibrations regularly, are most likely to be affected. Some people experience a number of symptoms after a few months, while others after many years of exposure.

Detection of problems

• Manufacturer usually states the vibration level that equipment produces at nominal operation. Using a hammer or a similar tool for more than half an hour on daily basis is considered hazardous for human health. The same goes for someone who uses a rotating tool (e.g. a lap) for more than 2 hours every day. Regular questions to personnel (every 6 months) usually prove to be valuable in locating problems. The standard questions are:
  
• Do hands turn white when exposed to low temperatures?
  
• Do hands ache or tingle each time you use a vibrating hand tool?
  
• Do you suffer from hand muscle or joint problems? Do you experience difficulties in handling small items such as screws or nails?
  
  

Preventive and safety measures

There are many prevention measures available, some of which considered low-cost, that may improve productivity and quality, such as:

• Introduce alternative ways of performing a task in order to eliminate exposure to vibrations
  
• Ensure that all personnel use the right tools for each task (improper equipment may stall works or produce stronger vibrations)
  
• Reduce exposure to equipment which produces vibrations (exchange working posts occasionally)
  
• Minimize continuous work intervals with vibration–producing equipment (perform other tasks in-between)
  
• Organize production processes in a way that leads to avoiding uncomfortable human body postures which may cause hand strain
  
• Perform frequent and adequate maintenance of all equipment
  
• Replace anti-vibration accessories frequently
  
• Inspect rotating parts for eccentricity and replace if necessary
  
• Keep cutting machinery and cutting tools sharp