Spray Foam Application Heat Stress
For as long as spray foam insulation has been available, protecting workers from severe heat exposure has been a major concern. The applicator’s head and body are often within two feet of the applied product, which can reach a staggering 165 degrees Fahrenheit in an attic application. The reaction of spray foam material when applied to a substrate radiates much of that heat into the air, exposing the sprayer to sweltering temperatures. All the while, the sprayer is wearing a mask or hood assembly respirator, a full body suit and gloves, which trap their natural body heat. While intense heat can certainly be irritating for the sprayer and helper, the impact is more than an issue of comfort. There are significant safety, liability and productivity considerations as well.
When the outside temperature increases, the body tries to cool off by directing more blood just under the skin and by perspiring. When the body is no longer able to keep its temperature in check, a condition called heat stress sets in and the effects can be severe. Symptoms include irritability, weakness, shivering and disorientation. Prolonged exposure may result in heat stroke, which is characterized by chills, convulsions and a loss of consciousness. Any respirator user that is not being supplied with the proper cfm amounts is going to breathe back in their own carbon dioxide. The majority of fresh air supply systems offer only a limited amount of CFM’s above OSHA/NIOSH standards. The Tennessee Chill Box supplies almost 100 CFM’s! If a public library needs 20 CFM’s per person, reading a book in an air conditioned building, why would a contractor purchase a compressed air supply system that delivers 10 to 15 CFM’s to a man in a 150 degree attic?
In extreme cases, the health consequences can be dire. In a recent five-year period, there were 3,442 worker fatalities linked to heat. This should be of particular concern to employers who conduct spray foam insulation services, as the average working conditions for applicators and helpers are very difficult.
Even in less severe circumstances where clear physical symptoms aren’t evident, intense heat can affect the sprayer’s ability to perform work successfully. A growing body of research indicates that heat stress hinders one’s ability to concentrate and perform tasks that require even a moderate level of skill. As a result, employees work at a slower pace and with less accuracy. Because spray foam is often used in applications where insulation needs and factors are critical, the significance of each error is magnified. Mistakes that go undetected can not only damage the company’s reputation for reliability and quality, but can be a liability and cause danger if a critical thickness of material is made with less accuracy. Even those that are caught can be costly to correct, and neither outcome is one today’s companies can afford.
Naturally, manufacturers and contractors have taken a number of measures over the years to combat heat exposure, such as ventilation of spray areas, using fans for spot cooling and controlling humidity with dehumidifiers. Companies have also mandated frequent water breaks to rehydrate employees, equipped sprayers with protective clothing and used cooling vests to lower the individual’s core temperature. While these measures have been somewhat effective, each comes with certain limitations as well. For instance, it can sometimes take up to 24 hours for someone to fully rehydrate by consuming fluids, and repeated trips to get water can curb productivity and create production bottlenecks. Vests that expose the chest and back to cool water can lower body temperature, but are heavy, cumbersome to wear all day and can create productivity challenges of their own since refilling may be frequently required.
How Does Heat Stress Affect Productivity?
Because of the prolonged exposure to heat experienced by sprayers, the risk of bodily harm is very real. When temperatures rise above 90 degrees, heat cramps and sunstroke are possible with lengthy physical activity; above 105 degrees, these conditions become probable. Typical retro attic applications can soar past 150 degrees during spring through fall.
However, heat can have a detrimental effect on mental activity and motor skills, even before bodily symptoms are present. A number of studies over the years have addressed the impact of heat exposure on worker performance. The clear conclusion from this body of research is that employees become not only less productive, but also less accurate, when the air temperature around them is well above the comfort range.
A comprehensive review of existing research that was published in the journal Ergonomics noted a gradual deterioration of worker performance when exposed to hot environments. In cases where the research subjects were exposed to temperatures of 90 degrees or higher, the reduction in performance was as high as 15 percent when compared to normal conditions.
In 2005, American and Finnish researchers published their own review of heat-related research and arrived at remarkably similar conclusions. The authors cited a consistent and proportional decline in productivity as a result of heat. On average, output dropped 2 percent for each degree above 77 degrees. That means that a sprayer exposed to a 90 degree environment would be able to perform 26 percent less work. Compound the loss of production with sprayers and helpers calling in sick of being sick.
The effect of this phenomenon from a business perspective is substantial. If the production of a single sprayer is valued at $75,000 a year, even a 5 percent drop in productivity means that company is seeing a $3,750 reduction in revenue. Of course, the effect is multiplied for each sprayer the business employs.
Evidence suggests that working in intense heat for several hours a day can also affect the employee’s quality of work. One early and very influential study evaluated the performance of workers who were subjected to different room conditions. At 80 degrees, the workers made five errors per hour and 19 errors after three hours. When the temperature was raised to 90 degrees, the workers made nine mistakes per hour and 27 after three hours. At 95 degrees, the workers made 60 mistakes per hour and 138 after three hours. Overall, the study concluded that a similarly hot environment will produce a proportional amount of errors regardless of task. Inversely, it can be calculated that by cooling the worker 15 degrees, they will make approximately 90% fewer errors.
Increased errors can have a substantial financial impact on a business with sprayers. To give a hypothetical example, if a crew working at 95 degrees makes 100 errors in a week, and the cost of correcting each mistake is $20, the cost of those errors is $2,000 during that stretch. If you could reduce sprayers’ temperature to 80 degrees, the number of heat-related errors could be reduced to 10, for a total cost of $200. That translates to a total savings of $1,800 per week. Even if the number of errors were reduced by just 50 percent, the company saves $1,000 each and every week.
More recent studies have supported this relationship. In one 2007 experiment, utility workers were asked to set up a mock power line in both indoor and outdoor environments. Subjects who performed the work in hot outdoor weather (between 90 and 100 degrees) without any cooling gear made 78 percent more errors than those who did the same tasks inside. Many spray foam contractors refuse to bid retro work during the hot summer months.
Another consideration when it comes to productivity for the entire business is the role that proper risk management plays. Laws protect workers from occupational injuries associated with exposure to high temperatures over a prolonged period of time. Adopting technologies as part of an integrated heat management plan may help control time and resources spent dealing with legal liabilities associated with heat related injuries. Each company’s situation is different and they should make their own assessments in consultation with legal advisors.
What Steps Can You Take?
Given the health risks and detriment to performance associated with lengthy heat exposure, manufacturers and contractors are looking for cost-effective ways to keep their sprayers cool. The old school continues to take breaks and consuming liquids throughout the day can certainly be part of the solution, although rehydrating the body can result in lost productivity. The preferred approach is one that keeps the employee comfortable and operating at peak performance without sacrificing total output. A significant downside of cooling vests that some sprayers use is their size and weight, which can make the worker uncomfortable and actually increase fatigue.
The TENNESSEE CHILL BOX is the only logical choice for respirator protection. Please allow us to share our history with you, and explain the benefits of our systems. Visit us at www.tennesseechillbox.com or call our office at 423-710-1476.
We will be the best investment you will ever make.
Mike Asbra, Inventor
- Centers for Disease Control & the Bureau of Labor Statistics
- U.S. Department of Labor
- National Oceanic and Atmospheric Association
- J.J., Nadler, E. and Busch, C., 2002, Effects of hot and cold temperature
- Seppanen, O., Fisk, W.J. and Faulkner, D., 2003. Cost benefit and analysis of the night-time ventilative cooling in office buildings. Lawrence Berkeley National Laboratory.
- Mackworth, N.H., 1946. Effects of heat on wireless telegraphy operators hearing and recording Morse messages. British Journal of Industrial Medicine, 3, 143-158.