Health and Safety ReportJuly 2010 - Volume 8, Issue 7

It's called giant hogweed for a reason. This plant can stand as high as 15 to 20 feet with leaves that can grow up to five feet wide. And although the size is impressive, the hazard giant hogweed poses to human health is just as big. If you come into contact with giant hogweed sap your skin can become extremely sensitive to sunlight, resulting in severe burns and blisters.

Giant hogweed (Heracleum mantegazzianum) is part of the parsley or carrot family, and except for its larger size, it looks very much like cow parsnip. The plant has hollow stalks and stems that range from 2 to 4 inches in diameter, with dark reddish-purple splotches and coarse white hair. The plant produces flattened oval shaped fruit and forms small white flowers that bloom from June to August. Each of the huge flower heads can produce up to 100,000 seeds that can lie dormant in the soil for up to 15 years.

Health hazards

A clear and watery sap is found in the stem and hairs of giant hogweed. Contact with the sap itself is not painful. However, skin that comes into contact with the sap can become extremely sensitive to ultraviolet light in sunlight.
A few quick facts:

• The reaction can occur up to 48 hours after contact.


• The resulting rash and blisters can develop into purplish or blackened scars that may last for long periods of time.


• Depending on individual sensitivity, effects can last for months.


• The skin can remain sensitive to ultraviolet light for years.


• Temporary or permanent blindness can occur if the sap gets into your eyes.

Where giant hogweed can be found

Originating from the Caucasus Mountains and southwestern Asia, giant hogweed was brought to Europe, the United Kingdom, Canada and the United States as an ornamental garden plant. Over time it escaped and invaded new environments in many of the places where it was first introduced including Ontario, New Brunswick, Nova Scotia, British Columbia, and Newfoundland and Labrador. Sightings in other regions continue to be reported as the plant spreads. It often grows along streams and rivers, forming a dense canopy that overtakes native species. Giant hogweed is also found along roadsides and railways, waste areas, fields, and vacant lots. It prefers moist soils and partial shade, but may also grow in full shade to full sun.

Protect yourself

When working near these plants, avoid getting sap on your skin. Cover your body from head to toe with protective, nonabsorbent clothing made from synthetic, waterproof material: long sleeved shirts and pants, gloves with long cuffs, boots and protective coveralls. Protect your eyes and your entire face. To prevent contamination, remove your clothes and gloves by turning them inside out. Avoid putting soiled clothes in contact with other objects or clothing and wash them well before any further use.

What to do if you get sap on your skin:

• Remove the sap as quickly as possible without rubbing and spreading it by blotting it with absorbent cloth or paper.


• Wash the affected area thoroughly with soap and water, and then rinse thoroughly.


• Wash and rinse your hands afterwards.


• Change and wash your clothes to avoid contaminating yourself or other people.


• Cover affected areas with protective clothing (gloves, long pants, and long sleeves) to avoid any exposure to light (sun or artificial light) for at least 48 hours.


• See a doctor as soon as possible if your skin reacts.

If you get sap in your eyes:

• Rinse your eyes thoroughly with clean water for at least 10-15 minutes.


• Wear dark sunglasses to protect your eyes from any exposure to light.


• See a doctor as soon as possible.

Plant removal

It is best to have a licensed weed exterminator remove giant hogweed from private property. However, if you choose to remove the plant yourself get professional advice to protect yourself.

Additional Resources

Download the free educational poster for outdoor workers from the Province of Ontario and Guelph University

Watch the video, Attack of the Giant Hogweed, WorkSafeBC

Ontario Weeds: Giant Hogweed at Ontario Ministry of Agriculture Food and Rural Affairs

More information from Weed Info.ca

No sooner had summer arrived then weather stations were issuing heat advisories. For some workers, the heat is a serious occupational hazard.

The human body is usually good at maintaining its ideal temperature of 37°C. At any time of year and in various circumstances, the body produces heat from muscle use and prevents overheating by sweating. In extreme temperatures however, when the air is as hot or hotter than the body, the cooling mechanisms don't work. When the body can no longer cool itself properly, a number of heat-related health problems may occur.

Heat stroke and heat exhaustion are the most serious health illnesses caused by hot environments, and a real danger to people who work outside in the summer. In outdoor occupations such as construction, road repair, open-pit mining and agriculture, summer sunshine is the main source of heat. In laundries, restaurant kitchens, and canneries, high humidity adds to the heat burden. In all instances, the cause of heat stress is a working environment which can potentially overwhelm the body's ability to deal with heat.

Without immediate medical attention, heat stroke can be fatal. In previous years, people have died at work of heat stroke in occupations ranging from agriculture workers to football players. Heat exhaustion and fainting are other less harmful heat-related health risks that can cause temporary illness.

Know the warning signs

Heat stroke victims usually don't recognize their own symptoms. Their survival therefore depends on their co-workers' abilities to detect symptoms and seek first aid and medical help immediately.
While the symptoms vary from person to person, they include dry, hot skin (due to failure to sweat), a body temperature often exceeding 41°C, and complete or partial loss of consciousness.

Signs of heat exhaustion (caused by loss of body water through excessive sweating) include heavy sweating, weakness, dizziness, visual disturbances, intense thirst, nausea, headache, vomiting, diarrhea, muscle cramps, breathlessness, palpitations, tingling and numbness of the hands and feet.

How to prevent health problems from overheating

Avoid sun exposure. Move some tasks indoors or into the shade. When that's not possible, erect a temporary shelter. Take frequent breaks in a cool or well-ventilated area to get out of the sun and heat.

Don't be afraid to sweat. Sweating is the body's most effective cooling mechanism. The cooling occurs as sweat evaporates. In some cases a fan can be used to move cool air into a room and help keep body temperatures down.

Become acclimatized. Don't take on strenuous activities too soon if you're not accustomed to the heat. It can take six to seven days for the body to fully adapt (or acclimatize) to a new thermal environment. Ease into your tasks gradually, taking frequent breaks from the heat as needed. It is advisable to assign about half of the normal workload to new employees or those back from vacations or illnesses on the first day of work and gradually increase day by day.

Stay hydrated. Drink plenty of cool water (on average one litre every hour) in hot weather conditions. Drink every 15 to 20 minutes whether you feel thirsty or not to replace the fluid loss. Avoid consuming caffeine and alcohol, which can dehydrate you.

Clothing. For protection from the sun and heat when working outside, cover up as much as possible with loose-fitting clothes made of a light fabric that "breathes". When you work in the sun without a shirt or hat, the sun dries your sweat too quickly and prevents it from cooling the body. Clothes give sweat a chance to cool the body, and help protect the skin from the sun's harmful rays.

Emergency action plan. An emergency plan should include procedures for providing affected workers with first aid and medical care. Workplaces where heat stress can occur should monitor conditions and ensure that workers get specified rest periods dependent on the measured heat levels. The Threshold Limit Values for Heat Stress and Strain, produced by the ACGIH (American Conference of Governmental Industrial Hygienists) offers guidelines to determine when the weather should have no effect on outdoor workers, when caution should be exercised and when work should be discontinued.

Learn more about health effects of hot environments, CCOHS

Provincial regulations concerning heat

Working in Hot Environments: Health and Safety Guide, CCOHS

Listen now to the CCOHS podcast: Working in the Heat: How Hot is Too Hot?
(Length: 6:11 minutes)

Health care professionals who treat patients with neck pain, ranging from mild pain to whiplash, will want to take notice of a new report released by the Institute for Work & Health (IWH). The Neck Pain Evidence Summary outlines the research gathered by The Task Force on Neck Pain and Its Associated Disorders (Neck Pain Task Force) from 1999-2008. The summary provides guidance on the grades of neck pain, helpful treatments and patient assessment.

Neck pain is common among workers, whether it be caused by lifting heavy objects, being rear-ended in a car accident, sitting for long periods at a desk job, or by one of myriad other reasons. While neck pain can't always be cured, there are a variety of available treatments. The question is, which treatments are the most effective?

Established in 2000, the Neck Pain Task Force has sought to find the answer. Comprised of scientists and clinicians in disciplines that actively treat patients with neck pain, the international task force's mandate is to recommend clinical practice guidelines for the management of neck pain and its associated disorders. Their work has produced a comprehensive picture of neck pain including its causes, how many workers report it, and how it progresses, and has been published in more than 20 research studies and "best evidence" systemic reviews.

The IWH worked with the Canadian Memorial Chiropractic College, the Ontario Chiropractic Association, and members of the Neck Pain Task Force executive committee to prepare the summary.

Download the report from IWH: Neck Pain Evidence Summary

The Workplace Hazardous Materials Information System (WHMIS) is working toward adopting the new Globally Harmonized System of Classification and Labeling of Chemicals (GHS). The Canadian Centre for Occupational Health and Safety (CCOHS) has created a new guide to introduce Canadian workers to GHS and to help workplaces prepare for potential changes.

The goal of GHS is to have the same set of rules for classifying chemical hazards and the same format and content for labels and safety data sheets (SDS) adopted and used around the world. WHMIS After GHS: Preparing for Change is geared to guide organizations through the anticipated changes, assist in the understanding of the new requirements, and facilitate a successful transition to "WHMIS After GHS."

While exact details of the revised legislation will not be known when it is published in the Canada Gazette II, sufficient information is known to encourage workplaces to begin preparing for changes. This overview covers the basics of classification, safety data sheets, symbols and pictograms, labels, hazard statements, and precautionary statements.
CCOHS publications are unique in that they are developed by experts in the field and reviewed by representatives from labour, employers and government to ensure the content and approach are unbiased and credible.

More information about WHMIS After GHS: Preparing for Change

Take the free e-learning courses from CCOHS:

• WHMIS After GHS: An Introduction


• WHMIS After GHS: How Suppliers Can Prepare

Every month new free podcast episodes are added to the Health and Safety to Go program. The most recent episodes provide tips on how to stay safe in a lightning storm, how to protect yourself from sun exposure and how to use Twitter to enhance your social media health and safety initiatives. You can listen now or you can download to your MP3 player and listen when it is most convenient for you.

Lightning Safety Listen now.

CCOHS discusses how to stay safe during a lightning storm.

Length: 5:17 minutes

Safety in the Sun Listen now.

CCOHS discusses the importance of staying safe while working in the sun and the preventative measures you can take to protect yourself from harmful UV rays.
Length: 3:53 minutes

Twitter Tips Listen now.

Krista Travers, Marketing Communications Officer at CCOHS, discusses 10 Twitter tips that will enhance your social media health and safety initiatives.
Length: 6:51 minutes

You can see a complete listing of all podcasts on the CCOHS website.