Exposure to excessive vibration can result in injuries and diseases such as vibration white finger, Raynaud's phenomenon, and carpal tunnel syndrome. In extreme cases, these injuries and diseases can lead to permanent impairment of the hands and arms.

Vibration can be explained as the back and forth motion produced by objects such as tools, machinery and equipment. It has two components:

• Frequency (or repeat rate)
• Amplitude (or displacement)

The risk of vibration-induced injury depends on the average daily exposure as well as the individual's sensitivity to vibration. An evaluation considers the intensity and frequency of the vibration, the duration of exposure, and the body part that receives the vibration energy.

Special caution should be exercised when workers are exposed to vibration in cold conditions, which may require reduced exposure limits.

As an employer, you must:

• Comply with, and ensure compliance with, the threshold limit values for exposure to physical agents as listed in the TLVs^® and Biological Exposure Limits (BEIs)® as determined by the American Conference of Governmental Industrial Hygienists (ACGIH^®). [N.S. Reg. 52/2013, s.2.3]
• Acquaint your employees with the hazards and control measures associated with their work.
• Provide the information and instruction necessary to ensure their health and safety.
• Enforce company safety rules, programs, codes of practice and procedures, including making sure employees follow the requirements below.

As an employee, you must:

• Be aware of the risks of using powered equipment with high-frequency vibration or high impact for extended periods.
• Be aware of the symptoms of the HAVS.
• Be aware of the daily exposure limits of the hand-arm vibration.
• Notify your supervisor and your joint health and safety committee if you experience symptoms of HAVs and seek medical attention.
• Follow and use the precautionary measures provided.

Hand–Arm Vibration

Employees who operate powered equipment with high-frequency vibration or high impact (such as chainsaws, grinders, jackhammers, impact wrenches, or sanders) for extended periods are at high risk of hand-arm vibration injuries. The adverse effect produced by exposure to vibration is called hand-arm vibration syndrome (HAVS).

Employees affected by HAVS commonly report:

• Numbness
• Attacks of whitening (blanching) of one or more fingers when exposed to cold
• Tingling and loss of sensation in the fingers
• Loss of light touch
• Pain and cold sensations between periodic white finger attacks
• Loss of grip strength
• Bone cysts in fingers and wrists

Attacks are usually triggered by cold temperatures or contact with cold liquids or solids. Cold weather and smoking are important aggravating factors. Both increase the risk of HAVS and may precipitate an attack.

Some preventive measures include:

• Identify the jobs or occupations that require the use of powered hand tools.
• Evaluate the extent of use of the equipment, including how long (duration) and how intense the exposure to vibration is.
• Determine if there are any employees showing HAVS symptoms.
• If vibration is a concern, develop a procedure for the use of tools, equipment, or machinery. The procedure should include, but not be limited to, the following items:
• Tool selection (buying anti-vibration tools, choosing the proper tool for the job, etc.).
• Alternative tools and methods for certain jobs (such as hydraulic tools in place of vibratory tools).
• Information and training to employees in the proper use and handling of tools and equipment and recognizing HAVS symptoms.
• Mandatory rest periods (10 minutes or more every hour) for vibratory tool operators.
• Regular inspections and equipment maintenance.
• Selection and use of anti-vibration gloves.
• Pre-placement and periodic medical evaluations of employees exposed to vibration.
• Monitoring exposure to vibration

As an employer, you must ensure compliance with the TLVs^®:

Table 1: TLV^® and Weighted Acceleration Levels

Source: 2024 TLVs^® and BEIs^® - Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices. Cincinnati: American Conference of Governmental Industrial Hygienists (ACGIH^®)

Whole-Body Vibration

The ACGIH^® Threshold Limit Values (TLVs^®) for whole-body vibration provide guidelines for the maximum levels of vibration exposure that workers should experience. These TLVs^® are based on how long (duration) and how intense the exposure to vibration is.

It is recommended that operators or occupants remain below these TLV^® levels during any 24-hour period to minimize the risk of adverse health effects. Additionally, action may be necessary if vibration exposure falls between the TLV^® and Action Level (AL) indicating a need to reduce exposure. The Action Levels (ALs) are also shown on the graph and listed in the table, indicating levels of vibration exposure that may require action to reduce the risk.

Table 2: TLV^® and AL Vector Sums of the Overall Weighted rms Accelerations (m/s^-2 rms)

Source: 2024 TLVs® and BEIs® - Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices. Cincinnati: American Conference of Governmental Industrial Hygienists (ACGIH®)

It's important to note that individual factors such as psychological and physiological differences can influence how someone responds to vibration exposure, and the TLVs should be used as guidance rather than strict boundaries between safe and unsafe levels of exposure.