Health and Safety ReportVolume 9, Issue 9

On Topic

Putting the Squeeze on Carpal Tunnel Syndromeprint this article

What does a baker kneading dough, an assembly line worker using power tools and a surgical nurse picking up and handing off delicate instruments have in common? Their work involves repetitive wrist movements or vibration that may put them at risk for carpal tunnel syndrome.

The carpal tunnel is a narrow space in the wrist surrounded by bones and a rigid ligament that houses the flexing tendons of the fingers and thumb as well as the median nerve. The median nerve, which runs from the forearm into the palm of the hand, controls the actions of the thumb, index, middle and ring fingers. If the tendons swell and press or squeeze the median nerve you may develop carpal tunnel syndrome. Certain job tasks, like repetitive wrist movements, or exposure to vibration can put you at risk of this painful disorder.


If you are experiencing tingling in the thumb and index, middle, and ring fingers, night pain, and pain in your hand, arm and shoulder you may have carpal tunnel syndrome. If the carpal tunnel syndrome progresses, you may also feel numbness, loss of manual dexterity, and weakness of the hand making it difficult to pinch and grasp. You may drop objects or be unable to unscrew bottle caps, fasten buttons or turn keys with the affected hand. Your skin may dry because of reduced sweating.

Who is at risk?

If you are a woman, you are three times more likely than a man to develop carpal tunnel syndrome, perhaps due to the generally smaller size of the carpal tunnel. Also at high risk are people with certain diseases and conditions, such as arthritis, diabetes, pregnancy and cysts, which directly affect the body's nerves and make them more susceptible to compression.

In the workplace those at risk for injury include people whose job tasks involve repetitive hand or wrist movements, awkward hand positions, strong gripping, mechanical stress on the palm, and vibration. Workers at higher risk for carpal tunnel syndrome include bakers who flex their wrists while kneading dough, as well as those using power tools, performing assembly line work, manufacturing, sewing, finishing, cleaning, and meat, poultry, or fish packing. Carpal tunnel syndrome is three times more common among assemblers than among data-entry personnel. Some studies show that psychosocial factors (such as stress) can contribute to the development of carpal tunnel syndrome.


The key to protecting workers from developing carpal tunnel syndrome is reducing the risk factors, mainly their requirement to flex fingers and wrists to perform their jobs, and avoiding excessive use of vibrating hand tools.
This means that work stations, tools or even the job may have to be redesigned to eliminate the risks, and workers must be informed about the risk factors that can contribute to carpal tunnel syndrome.

Proper work station design that enables the work station to be adjusted to fit the employee reduces awkward wrist positions, and minimizes the stressful effects of repetitive motions.

It is also important to redesign tools to alleviate the need to bend and flex wrists. A study in a poultry processing plant found that workers who used knives with a bent handle rather than the standard straight handle, no longer needed to bend their wrists while cutting the meat. This change greatly reduced the occurrence of carpal tunnel syndrome.

Good job design enables the worker's wrist to maintain a natural position during work, minimizes tasks with repetitive motions as well as the need to use forceful exertion and provides variety in tasks performed to provide a break from the vibration that accompanies the use of powered hand tools.

Good job design includes the following:

  • analysis of the sequence of the tasks to allow changes in body position

  • work-rest schedule to relieve muscles from mechanical stress and vibration

  • work breaks to avoid monotonous and repetitive patterns of work

  • rotation of tasks to move workers from one job to another

The prevention of carpal tunnel should also include a training and education program that is organized, consistent and ongoing. Workers should be informed about the risk factors and trained on correct posture and wrist position to be used on the job, ways to reduce the number of repetitive motions and the importance of making sure that rest and work breaks are properly used.

Everyone at work, including workers, managers, and health and safety representatives, must get actively involved.

More information

Alerts & Bulletins

Safety in the Trenches print this article

Preventing Worker Deaths from Trench Cave-ins

Just last month a worker was rescued after the trench he was working in collapsed around him. He spent four hours buried to the waist in soil, however he survived the incident with minor injuries. The outcome was comparatively better than that of many others who perish every year in trench cave-ins.

The United States National Institute for Occupational Safety and Health (NIOSH) offers guidance on engineering controls, protective equipment, and safe work practices to minimize hazards and protect workers who are at risk of injury and death from cave-ins during trenching and excavating.

Risky business

Excavation sites can be hazardous and workers who dig the trenches are at risk of serious injury or death if the walls collapse. A trench can fail suddenly before workers have time to move out of the way. Soil is heavy. A single cubic yard of dirt can weigh more than 1360 kilograms (3,000 pounds) - enough to crush or suffocate a person.

There are precautions employers and employees can take to prevent injuries and deaths and address the hazards they face in trenching and excavation work.

What employers can do

Before the job begins:

  • Train and designate a competent person to ensure safety measures are in place.

  • Contact utility companies before digging to have utility lines marked, then hand dig test holes or potholes to expose utilities and determine their exact location and depth before excavating.

  • Evaluate the soil to determine its stability, keeping in mind that soil conditions can change substantially over a few days.

  • Plan the job layout to identify safe locations, well away from the trench, for spoil piles (excavated material) and heavy equipment routes.

  • Determine what type of protective system (shoring, shielding, or sloping) will be used for the job and have the system in place before workers enter.

  • Consult an engineer for more complex trenches greater than 20 feet deep, to determine the appropriate protective system that should be used.

  • Ensure that everyone working in the trench is aged 18 or over.

  • Ensure that workers involved in the job are trained about hazards and work practices in a language and literacy level that they understand.

  • Develop a trench emergency action plan to describe steps to be taken in case of an emergency, and ensure it includes emergency contact information.

Operating safely during the job:

  • Inspect the excavation, adjacent areas, and protective systems each day before the start of work, as needed throughout the shift, and after every rainstorm.

  • Notify subcontractors of the trench location and precautions, and ensure that vehicles are kept a safe distance from the excavation. Ensure that ladders and other means of exit are never more than 25 feet away from any worker in the trench.

  • Remove workers from the trench if any situation is detected that could cause a cave-in, such as water in the trench or problems with the protective systems.

  • Monitor other types of trench-related hazards that can occur such as falls from the edge, rigging hazards, or toxic and combustible gases.

  • Implement and enforce procedures to ensure that work in an unprotected trench is not permitted.


  • Do not enter an unprotected trench.

  • Inspect the protected trench before entering.

  • Exit the trench and call your supervisor if you see any evidence of problems with a protective system.

  • Do not assume there will be a warning sign before a cave-in or that you will have time to move out of the way so immediately report potential problems at the first sign of any trouble.

More information

More information about trenching and excavation, NIOSH

Preventing Worker Deaths from Trench Cave-ins, NIOSH

Trenching (Construction Health and Safety Manual), PDF, Infrastructure Health & Safety Association

Trench Digging and Excavation Safety (video), Ontario Ministry of Labour

Tips & Tools

Losing Scents at Workprint this article

Making the Move to a Scent-Free Workplace

Watery or itchy eyes. Sneezing. Headaches. Nausea. Breathlessness. Wheezing. These are just a sample of the symptoms experienced by people with fragrance sensitivities when they are exposed to the chemicals in scented products.

Reactions to fragrances can vary from one person to the next, however once a person has developed fragrance sensitivity, it may continue to get worse over time and with repeated exposure.

Scents are found in countless products that we use every day including soaps, detergents, household cleaners and personal care products such as shampoo, body wash and aftershave. And although these products may smell pleasant, for your coworker with scent sensitivities, they may come with unpleasant health effects.

The person wearing scents can be affected by them as well as anyone they come into contact with. This can create a challenge in the workplace where people interact or sit close to one another. Some workplaces promote the "arm's length" rule: that no scent should be detectable at more than an arm's length from the individual. Others are going one step further and adopting a scent-free policy for their workplace.

CCOHS has tools to help make the transition easier.

Webinar: Learn about the issue of scent sensitivities

Join CCOHS' Senior Technical Specialist for a free thirty minute webinar about scent sensitivities and the challenges faced in the workplace:

Making Sense of Scent-Free Workplaces

October 20, 2011 1:00 PM EST

Register now for the webinar.

Poster: Raise awareness of scent sensitivities

Post the "Air Aware" poster and inform your employees about the issue of scent sensitivities and help them understand how fragrances can impact the health of their coworkers. Get everyone on the same page with this important workplace health issue.

Poster: Designate areas or your building as "scent-free"

Post the "Scent-Free Zone" poster in work areas or buildings designated as "fragrance-free" as a reminder to employees and visitors. It clearly advises people not to wear perfume, cologne, aftershave and other fragrances, and to use unscented personal care products.

Button: Spread the message

Provide your employees with buttons that let them show their support for a fragrance-free environment, by declaring, "I'm air aware".

Ask for everyone's assistance in maintaining a fragrance-free workplace - so that all may be able to breathe easy.

Additional resources

Learn more about the health effects of fragrances and how to set up a scent-free policy for the workplace from CCOHS.

Learn about scents and indoor air quality from The Lung Association.

Download the free Air Aware poster from CCOHS.

Download the free Scent-Free Zone poster from CCOHS.


Proper Lighting and Workplace Mental Healthprint this article

CCOHS produces free monthly podcasts on a wide variety of topics designed to keep you current with information, tips and insights into the health, safety and well-being of working Canadians. You can download the audio segment to your computer or MP3 player and listen to it at your own convenience...or on the go!

This month's edition of Health and Safety To Go! features Proper Lighting in the Workplace. The podcast explores how poor lighting can affect worker productivity, and offers tips on conducting a lighting audit.

The podcast runs 2:31 minutes. Listen to the podcast now.

Encore podcast: Mentally Healthy Workplaces

In this podcast Donna Hardaker, Workplace Mental Health Specialist for the Canadian Mental Health Association, discusses mental health in the workplace and how to relieve workplace stress.

The podcast runs 8:24 minutes. Listen to the podcast now.

See the complete list of podcast topics. Better yet, subscribe to the series on iTunes and don't miss a single episode.


Healthy Minds at Workprint this article

Addressing Mental Health in the Workplace

When people go to work, all aspects of their lives follow them there whether it be family pressures, job stresses, emotional turmoil, or relationship woes. For some, it can be challenging to keep emotionally healthy and engaged in their work. With the number of waking hours workers spend on the job, the workplace environment can have a profound impact on their mental health and well-being.

The mental health of your employees impacts their productivity, ability to concentrate, and their interactions at work. When people are mentally well, they are more likely to fulfill their potential and cope with daily pressures in the workplace. Healthy work environments play an important role in reducing stress levels, creating a positive approach to work, and improving the mental well-being of employees.

To help workplaces recognize, understand and address mental health issues, CCOHS has launched the new Healthy Minds at Work website. This collection of quality online resources offers advice on how to create a healthy, supportive work environment, promote mental health, and effectively handle mental health issues that may exist - to improve workplace mental health for everyone.

More information

Visit the Healthy Minds at Work website.

Download the free Healthy Minds at Work poster.

Order "Working Well Together" buttons that your employees can proudly wear.

Last Word.

Work Safely with Radiationprint this article

Webinar Focuses on Radiation Safety in the Workplace

Radiation is all around us in Canada. Natural background radiation is found in soil, air, food, and water, but radiation is also used in healthcare, power generation, construction, manufacturing, research, and other workplace settings. Over 150,000 Canadians are monitored each year for occupational radiation dose, and many more are exposed during diagnostic or therapeutic medical procedures.

To help Canadian workers gain a greater knowledge of radiation, CCOHS has partnered with the Radiation Safety Institute of Canada to present a live webinar:

Radiation Safety in the Workplace

Presenter: Claire Cohalan, Scientist, Radiation Safety Institute of Canada

When: Tuesday, October 18, 2011, 1:00 pm – 2:30 pm EST

This online session will give participants a better understanding of what radiation is, the health effects of exposure, and some of the principles and practical methods of radiation protection. Gain the knowledge required to make informed decisions and opinions about radiation safety related issues, in any industry.

The cost of the session is $39 and includes a copy of the presentation slides, the ability to ask questions during the live session, and access to the recording.

Learn more and register online.

Visit the Radiation Safety Institute of Canada website.

Tell us what you think.
We welcome your feedback and story ideas.

Connect with us.

The Health and Safety Report, a free monthly newsletter produced by the Canadian Centre for Occupational Health and Safety (CCOHS), provides information, advice, and resources that help support a safe and healthy work environment and the total well being of workers.

You can unsubscribe at any time. If you have been sent this newsletter by a friend, why not subscribe yourself?

Concerned about privacy? We don’t sell or share your personal information. See our Privacy Policy.

CCOHS 135 Hunter St. E., Hamilton, ON L8N 1M5

© 2022, Canadian Centre for Occupational Health and Safety