Heat Stress

International Paper Cedar River Mill Curt Krambeer, Process Team Member Leon Hospodarsky, Manufacturing Support Team Member

What is Heat Stress Heat stress is defined as a condition in which the total net heat load on your body from internal heat production and external sources exceeds your body’s capacity to cool itself.

Why worry about Heat Stress A report from the U.S. Department of Commerce, states that a conservative estimate of the number of workers in industries where heat stress is a potential safety and health hazard would be 5 to 10 million workers. The CDC reported that during the 1999-2003 period a total of 3442 deaths resulted from exposure to extreme heat.

Levels of Heat Stress Mild or moderate heat stress may be uncomfortable and may affect performance and safety, but it is not usually harmful to your health. When heat stress is more extreme, the possible health effects or heat-related illnesses include: Heat edema: swelling. Heat rashes: tiny red spots on the skin, which cause a prickling sensation. Heat cramps: sharp pains in the muscles. Heat exhaustion: excessive loss of water and salt. Heat syncope: fainting. Heat stroke: the most serious level of heat stress.

Heat Exhaustion vs. Heat Stroke Heat Exhaustion: is caused by excessive loss of water and salt. Symptoms include: Heavy sweating (Eventually sweating may stop) Weakness Dizziness Nausea Headache Muscle cramps Heat Stroke: (elevated body temperature) is the most serious type of heat illness – life threatening and requires immediate medical attention. It is the worsening of all the heat exhaustion symptoms plus: Elevated body temperature greater than 41°C (106°F). Complete or partial loss of consciousness.

Personal Factors Tolerance to heat stress will vary from person to person (think: age, gender, body mass, medical conditions). An individual’s tolerance to heat will vary from day to day (think: food and liquid intake, sleep, clothing, drug/alcohol use). At a minimum, heat stress will generally decrease an employee’s judgment and workmanship.

Other Factors Affecting Heat Stress Air Temperatures What can be measured by a thermometer. Other sources of heat Direct sunlight, machinery that generates heat. Relative Humidity Moisture in the air. The more moisture in the air the less your body is able to sweat and cool itself. Moving air (speed) usually cools a person. Moving air will cool a person as long as the air moving is cooler than the person. (less than 37°C (98.6°F) Physical Exertion Moving around or working generates heat.

The Body’s Response to Heat Body works best when it has an internal “core” temperature of 37°C (98.6°F). During regular day, your body may vary by about 1°C (2°F). When you work in extreme hot temperatures, your body has to adapt. Sweat – evaporating sweat cools the body Increase blood flow to the skin – (radiate away excess heat)

Acclimatization People can adapt to hotter temperatures through a process called “acclimatization.” Acclimatization allows you to work more safely and efficiently. However, becoming acclimated takes time. (4 to 7 working days) Your body will learn to adapt, sweat more, conserve body salt, and reduce cardiovascular stress. Work schedules should consider acclimatization needs.

Developing a Heat Stress Program Prevention is your best defense against heat stress. Planning should include an analysis of work environments and job duties. Identify methods to limit employees’ exposure to heat. Education and training of employees. Evaluate effectiveness of program.

Analysis Various ways to measure heat. Thermometer: Air temperature Heat Index: Temperature + Humidity WBGT (Wet Bulb Globe Temperature) Index

WBGT Our Heat Stress Team chose to work with the WBGT (Wet Bulb Globe Temperature) This device monitors a dry bulb sensor that measures ambient temperature; a wet bulb sensor takes into account evaporative cooling, giving an indication of the effects of humidity on an individual; and a globe sensor provides an indication of the radiant heat exposure on an individual due to either direct light or hot objects in an environment.

WBGT continued The team performed studies in each mill during the summer of 2008, gathering information to determine potentially hot locations. In addition, the team worked with maintenance personnel to study the affects of moving and cooling the air for scheduled jobs. Data from the studies along with feedback from those working on the jobs was collected.

What did we determine? There are definite hot spots in the mill regardless of the time of year. Both maintenance and process have jobs that are more susceptible to heat stress regardless of the time of the year.

Red Zones A “Red Zone” was defined as having the capability of being a hot area regardless of the time of year. Those areas marked were: #1 PM #2 PM Pulpers – Op. Floor Pulpers – Op. Floor Saveall Saveall Dryer section (All) Dryer section (All) All of OCC Mezzanine from All of OCC Mezzanine from North Hatchway North. North Hatchway North. Top side of Machine Top side of Machine

Possible Control Methods Pre-work planning can decrease the chance of heat stress. Engineering controls (such as AC units). By using fans, misters, air horn, etc., we can control the environment. Using cooling PPE can help control body core temperature. Limiting the amount of exposure time will help.

Decision Tree

Risk Assessment Card

JPSA

Fan Maintenance Exhaust and Cooling Fans are critical to help cool these warm environments Team members are responsible to write work notifications for any permanent fan that requires attention Portable fans should be transported to the Shop for repair as necessary Area Process Owners will maintain fans

PPE Options Safety cooling vests Chill cap Chill It bandana Terry cloth tori band Sponge tori band

Hydration Options Additional water fountains Portable water coolers Extra bottled water when needed Gatorade stations Electrolyte packets Popsicles

Policy Development Heat stress policy updated to incorporate identified process improvements. Education and training required for all employees.

Education Symptoms Recognition Treatment Prevention is the key.

Training New hire orientation training Yearly refresher training First responder training Leadership training

Preventing Heat Stress Know signs/symptoms of heat-related illnesses; monitor yourself and coworkers. Block out direct sun or other heat sources. Use cooling fans/air-conditioning; rest regularly. Drink lots of water; about 1 cup every 15 minutes and electrolyte drinks in moderation. Wear lightweight, light colored, loose-fitting clothes. Avoid alcohol, caffeinated drinks, or heavy meals.

Scenario – OCC Sump Pump Belt Replacement (in July) Review Heat Stress Decision Tree Unplanned job in non - Red Zone Complete JPSA or Risk Assessment Card Per the JPSA or Risk Assessment Card consider whether any Heat Stress controls or PPE are necessary Stay hydrated!

Scenario – Removing Dryer Section Pileup (in August) Review Heat Stress Decision Tree Unplanned job in Red Zone Complete Risk Assessment Card Per the Risk Assessment Card use appropriate Engineering Controls and PPE for Heat Stress Examples of PPE include cooling vests Stay hydrated!

TIP! Intense thirst is not a good warning sign of heat stress, an unacclimatized worker may not experience thirst. If you experience thirst you are already becoming dehydrated! Prevention is your best defense against heat stress.