Overview

Hand-arm vibration is vibration that moves into the worker’s hands and arms through the palms and fingers.

This occurs when someone is working with or holding:

  • hand-held power tools (for example, sanders, jackhammers, rock drills, etc.)
  • hand-guided equipment (for example, lawnmowers)
  • materials being processed by machines (for example, using a pedestal grinder)

The risk of illness and injury due to hand-arm vibration depends on the frequency and magnitude (level) of the vibration, and the length of time a person is exposed to vibration.

Health risks

Workers who are regularly exposed to hand-arm vibration can develop damage to the soft tissues of the fingers, hands and arms. This causes symptoms that together are known as hand-arm vibration syndrome HAVS, which is an occupational illness.

HAVS: is a range of permanent injuries to a person's fingers, hands and arms that includes damage to the:

HAVS is irreversible and there is no effective treatment or cure.

Symptoms

  • symptoms may come and go over time however, they may become permanent with repeated and continued exposure to vibration.
  • symptoms generally occur after exposure to vibration over a few years, however they can occur after only a few months.

Vascular system

One symptom of HAVS that is present in the vascular system is episodes of whitening or blanching of the fingers. This symptom is sometimes called “Raynaud’s phenomenon of occupational origin” or “vibration-induced white finger.”

Vibration can damage small blood vessels and temporarily reduce blood circulation, making fingers turn white. This usually happens when the hands or body become cold or wet.

As blood flow returns to the fingers, they will turn red and are often painful. During a blanching attack, the worker can experience a loss of touch sensation and manipulative dexterity.

The severity of these attacks can be described using a 5-stage system called the Stockholm Workshop Classification System for Vibration-Induced White Finger. The stages are:

  1. No attacks.
  2. Mild: occasional attacks affecting only the tips of one or more fingers
  3. Moderate: occasional attacks affecting the end and middle of one or more fingers
  4. Severe: frequent attacks affecting all parts of most fingers
  5. Very severe: stage 3 symptoms, with trophic skin changes (changes in the skin due to disruption of the local nerves and blood vessels) in the fingertips

Workers exposed to vibration at the feet can also develop vascular symptoms in the feet, including vibration-induced white feet. 

Nervous system

Tingling and numbness in fingers and hands can be a symptom of HAVS. Continued exposure to vibration can worsen these symptoms and result in:

  • reduced sense of touch
  • reduced sense of touch temperature
  • impaired manual dexterity

Symptoms

Symptoms in the hand include :

  • tingling
  • numbness
  • pain
  • weakness

These can interfere with work activities and daily tasks.

The use of vibrating tools in combination with repetitive movements, forceful gripping and awkward postures may increase the risk of developing carpal tunnel syndrome.

Carpal tunnel syndrome

Exposure to hand-arm vibration can also increase a worker’s risk of developing carpal tunnel syndrome. Carpal tunnel syndrome is a condition in which a nerve passing through the wrist is compressed by inflammation (swelling) of other tissues.

Musculoskeletal system

Musculoskeletal system symptoms include muscular weakness, pain in the hands and arms.

Workers exposed to hand-arm vibration have reported:

  • wrist and elbow osteoarthritis
  • tendinitis in the upper limbs
  • Dupuytren’s contracture (in which fingers are pulled into a flexed position and cannot be straightened completely)

Tools that cause hand-arm vibration

Exposure to hand-arm vibration can be found in almost every job sector. However, it is most often seen in:

  • construction
  • forestry
  • mining and some industrial sectors, such as:
    • metal working
    • automotive manufacturing
    • furniture manufacturing

Commonly used hand tools where hand-arm vibration may be a concern include but are not limited to:

  • chainsaws
  • chipping hammers
  • demolition hammers
  • grinders
  • impact drills and wrenches
  • jackhammers
  • rock drills
  • sanders
  • saws
  • vibratory rammers
  • leaf blowers
  • lawn mowers
  • edge or lawn trimmers

Legal requirements

The following outlines the legal requirements under the Occupational Health and Safety Act (OHSA) regarding hand-arm vibration.

Limit exposure to hand-arm vibration

Employers have a duty under clause 25(2)(h) of the Occupational Health and Safety Act to take every precaution reasonable in the circumstances for the protection of a worker. This includes the protection of workers from exposure to hand-arm vibration.

Exposure to vibration is determined by two factors:

  • the amount of time a worker is exposed to vibration
  • the frequency-weighted root mean square magnitude of vibration

It is important to evaluate the risks to workers to understand:

  • the tasks and equipment that produce hand arm vibration
  • the worker exposure
  • the control measures that may be available to protect workers

Notify the Ministry of Labour, Immigration, Training and Skills Development of occupational illnesses

Conditions that are sustained due to exposure to hand-arm vibration are considered an occupational illness.

Under OHSA subsections 52(2) and (3) employers have a duty to provide written notice of occupational illness to the Ministry, the joint health and safety committee and the trade union, if any, within four days of being advised by or on behalf of a current or former worker that the worker has an occupational illness or if a claim in respect of an occupational illness has been filed with the Workplace Safety and Insurance Board. 

Conditions sustained from exposure to hand-arm vibration are considered occupational illnesses.

Under OHSA subsections 52(2) and (3), employers have a duty to provide a written notice of occupational illness, to the:

  • ministry
  • joint health and safety committee
  • trade union, if any

The employer must provide this notice within 4 days of learning that the worker has an occupational illness, or a claim of an occupational illness has been filed with the Workplace Safety and Insurance Board.

The employer may learn about this illness from a current or former worker, or from someone else on behalf of that worker.

Risk assessments

A hand-arm vibration risk assessment conducted by a competent person will allow the workplace to determine:

  • the tasks and equipment where vibration exposure is occurring
  • whether any worker is at an increased risk of injury

This assessment also allows workplaces to make informed decisions about measures to prevent or control health risks associated with hand-arm vibration exposure.

The risk assessment should:

  • identify if hand-arm vibration exposure may be causing or contributing to a health and safety risk
  • estimate hand-arm vibration exposures to workers and compare them to recommended limits
  • identify controls
  • identify steps to control and monitor risk

Exposure limits

The exposure limits for hand-arm vibration recommended by the American Conference of Governmental Industrial Hygienists (ACGIH) are reasonable as a benchmark to determine if a worker is at an increased risk of injury. The following is a summary of those recommendations from the (ACGIH) (2018).

Workers should not be exposed to a frequency-weighted root-mean-square daily (8 hours) vibration exposure above 5 m/s2 (meters per second squared, a standard unit of measurement).

A daily vibration exposure of 5 m/s2 is believed to be the maximum value that most workers can be exposed to repeatedly without progressing beyond Stage 1 of the Stockholm Workshop Classification System for Vibration-Induced White Finger.

Putting controls in place

Workplaces should consider putting controls in place when daily exposure reaches 2.5 m/s2. Examples of potential controls include:

  • educating workers about the signs and symptoms of HAVS
  • developing ways to eliminate or reduce exposure to hand-arm vibration, such as:
    • procurement procedures to purchase tools with lower vibration exposure emissions
    • regular tool maintenance schedules

For more information about reducing or eliminating exposure, see Preventing injuries.

Measure or assess workers exposure

Refer to the following two International Organization for Standardization (ISO) Standards to measure or assess workers’ exposure to hand-arm vibration.

ISO Standards

Mechanical vibration — Measurement and evaluation of human exposure to hand-transmitted vibration:

The European Union’s vibration publication

  • contains a good practice guide about hand-arm vibration
  • discusses how to determine exposure duration and magnitude
  • shows sample vibration magnitudes of some common tools and machines that present risk to workers

These sample vibration magnitude values, or values obtained from the manufacturer, can be used, along with the United Kingdom’s Health and Safety Executive’s “Hand-arm vibration exposure calculator” to estimate a worker’s level of exposure. This helps to determine if an in-depth risk assessment by a person knowledgeable in measuring vibration is needed.

Note: daily exposure limits recommended by the ACGIH are the same as limits in the European Union’s vibration publication and the United Kingdom’s Health and Safety Executive’s “Hand-arm vibration exposure calculator”, but are different from the general health effects values provided by ISO 5349-1:2001.

Preventing injuries

Controls are available to reduce or eliminate exposure to hand-arm vibration. When there is exposure in the workplace, measures should be taken to control exposure and prevent injury.

The appropriate workplace controls will be different, depending on the type of exposure and other factors. Some measures may include the following.

Elimination

The most effective method of preventing exposure to vibration is to remove the source of the vibration or remove the worker from the vibration, for example:

  • mechanisation or automation of tasks
  • remote operation of equipment
  • redesigning the task so that vibrating equipment is not used

Engineering controls

  • Purchase tools that are known to be below the recommended limits for hand-arm vibration exposure and are appropriate for the job.
  • Install vibration dampeners or isolators.
  • Ensure that tools and accessories are maintained and in good operating condition (for example, balanced, sharp cutting blades and bits, etc).
  • Provide jigs and anti-vibration handles designed to avoid the need to hold vibrating surfaces, reduce required grip strength or lessen the weight of the tool handled by the operator.
  • Reduce grip or push forces (reduces the vibration passing into the worker’s hands).

Administrative controls

  • Reduce the exposure to vibration by providing alternate tasks for the worker to perform in addition to working with vibrating tools.
  • Allow frequent work breaks when using vibrating tools.
  • Provide training and information to workers and supervisors regarding hand-arm vibration, including:
    • health effects
    • how to detect and report early signs of illness
    • potential sources of exposure
    • ways to decrease exposure, including safe work practices with vibrating tools
    • the effects of smoking on circulation and HAVS risk.
  • Keep warm at work, especially the hands. Wear warm gloves and extra clothing when working in the cold (cold temperatures reduce blood flow in the extremities.)
  • Avoid smoking, particularly prior to or while operating vibrating tools or equipment. Smoking constricts the blood vessels, affecting blood flow.

Personal protective equipment

If anti-vibration gloves are used, they should meet the requirements of ISO 10819:2013. However, the reduction in vibration magnitude is generally negligible so anti-vibration gloves alone should not be relied upon to protect workers from hand-arm vibration.

Contact us

If you need more information about safety requirements, please contact the Ministry of Labour, Immigration, Training and Skills Development Health & Safety Contact Centre at 1-877-202-0008 on Monday to Friday, from 8:30 a.m. to 5:00 p.m., or webohs@ontario.ca.

This resource does not replace the Occupational Health and Safety Act OHSA and its regulations, and should not be used as or considered legal advice. Health and safety inspectors apply the law based on the facts in the workplace.