Summer Beach

Keeping Cool Beyond OSHA

The Occupational Safety and Health Administration (OSHA) can trace its history back to President Nixon’s signature in 1970.  Driven by calls from labor unions and the increasing reality of deaths and disabilities in many industries, both OSHA and its sidekick NIOSH were born.  Interestingly, OSHA became a division of the Department of Labor while NIOSH (National Institute for Occupational Safety and Health) reported into the CDC, alias Health and Human Services.  Clearly the former deals with enforcement and the latter with research.

Since its inception OSHA has done much to improve industrial safety, often in response to tragic episodes.  Many efforts and compliance directives have focused on chemicals and pollutants such as asbestos, vinyl chloride, arsenic, lead, benzene, and carcinogens.  Unsafe working conditions have been eliminated or diminished in many industries including shipbuilding, meat packing, petroleum refining, sugar, grain, construction, textile, and process industries.

While such regulations have dealt appropriately with obvious industrial issues, it was not until 1987 that minimal initial standards were issued for the more subtle, seasonal, and variable issue of Heat Stress.  This originated in the fields where low wage braceros roamed from crop to crop to harvest our nation’s agricultural bounty.  These invisible and defenseless Mexicans would perform the “Stoop Labor” that was somehow a better living standard than in their own country.  The basic regulations demanding potable drinking water, toilet type facilities, and clean water for washing hands was an initial step and those instructions are still posted in most restaurant bathrooms to this day for kitchen help.

Now let’s fast forward to the Heat Stress Issues of today:

  • Many companies still look at resolving Heat Stress as a business cost and not an opportunity.
  • Heat Stress is addressed by “Definitions, Symptoms, and Guidelines”.
  • Manufacturing operations and distribution budgets are always under intense scrutiny, often by management in air conditioned offices not even on job locations.
  • Much of the OSHA standards, by necessity, deal with modifying work schedules where possible, emergency planning, supervisor training, and promoting adequate water and rest breaks.

In an effort to illuminate some issues regarding Heat Stress, consider looking at this issue in the light of significant benefits of cooling and the hidden cost of not cooling.

The negative impact of having a significant incident can be quite costly.  Of course there is the exposure to increased OSHA oversight, paperwork, and possible fines.  The 911 call, if necessary, can prove expensive if an ambulance is required.  Disruption or a slowdown of the work force for a length of time is natural.

In many industries finding and training new employees is significant.  Take an auto shop that competes with a new car dealer with a new air conditioned service area.  If it is 100 degrees in the summer, the risk of your best employee being enticed to a better work environment is something to think about.  And consider the onetime cost of investing in your worker comfort as opposed to the annual issue always being salary.

Now consider productivity.  Do workers work as efficiently when their glasses are fogging up or when the sweat is dripping off their noses?  How many water and rest breaks might be avoided if it were 10-12 degrees cooler?  How many errors are made that need to be reworked or retooled?  How many shortcuts are taken that lead to customer complaints?  However, possibly the greatest reason for reducing the heat is the feeling a work force gets when they believe that management cares a little about them and wants to make them more comfortable.  That can be a more valuable inducement than a pay raise.

What is Heat Stress and how is it measured? 

The Heat Index Table is considered THE BIBLE for Heat Stress measurement and is simply a combination of the temperature and the relative humidity (%).


As you can see, the combined impact of heat and humidity greatly increases as each one increases.

  • At 40% humidity and 88 degrees the index is only 88
  • At 40% humidity and 94 degrees the index is up to 97
  • At 40% humidity and 100 degrees the index is now 109
  • At 60% humidity and 88 degrees the index is up to 95
  • At 60% humidity and 94 degrees the index is up to 110
  • At 60% humidity and 100 degrees the index is now 129

Clearly, higher humidity climates are particularly at risk as the temperature becomes more intense.

The various types of heat stress symptoms correlate closely to the heat index.  Difficulties can vary from a heat rash or cramps to fainting, exhaustion, and stroke.  Most, if not all, OSHA professionals are well in tune with these relationship issues and I won’t labor to repeat the obvious here.

The most important solutions to Heat Stress are frequent rest and water breaks IN THE SHADE.  If laborers work in the sun they absolutely must have tents or shade sails available with cool water and seating.  In California, for example, it is a state OSHA regulation that there must be shade to accommodate at least 25% of workers at any given time.  To further cool workers, a mist line can be attached to the perimeter which will reduce the temperature by up to 20degrees.  Even if no faucet is available as a supply line, portable units are available with 12 volt batteries and booster pumps (200 psi) that do an excellent job for 5 hours without a water refill.


portable misting tent

Many industries have horrific issues with sugar or grain dust or petroleum processing vapors that can explode with a spark.  For those intense problems, Class 1, Div 2 explosion proof pumps are available, albeit at about triple the price of a regular pump.  Just the same, those industries are some of the most demanding on workers and the price seems insignificant compared to the human relief.

For intense heat, personal gear is available as vests with freezable ice packs that can last 2-3 hours or as air vests which are inflated by a compressed air tube; yes they are somewhat cumbersome, but also effective.

In the factory, warehouse, or shop floor, circulating fans to move air and exhaust fans to remove hot air from above have been a traditional method to make the air more bearable.  Large areas have found some relief by installing 8to 24 foot diameter ceiling fans under the brand names “ BIG ASS” or “Macro-Air”.

In the past decade a new and remarkable workplace cooling capability has emerged through the use of HIGH PRESSURE MISTING FANS.  Most likely, you have seen fogging fans on the sidelines at college and professional football games to chill players during intense heat of the summer and fall games.  These are similar to what some fire department use for emergency “BLAST” chilling of trauma burn victims.  When a boiler needs repair, or maintenance work is required by an individual or small team, high pressure portable misting fans can be filled with water, moved to locations, and run for 5-6 hours without a refill.  This can reduce the temperature by up to 30 degrees, not including the increased Wind Chill factor.

Portable Misting Fan

Misting fans have the advantage that many fans can be outfitted with nozzles and run off of a single pump.  They can be wall mounted, hung from support beams, or attached to pedestals.  Many people suspect that mist will wet equipment, product, and floors, but that is simply not true if the smallest orifice nozzle is utilized with 1000 psi pumps.cat_low_pressure_fans

In less humid areas (40 % or less) a simple 180 psi booster pump can suffice with a significant cost savings if no more than 25 nozzles are required for cooling 4-5 workers in auto shops and related venues.

In summary, because the impact of Heat Stress varies with the worker exertion level, humidity, and shade factors it is clearly up to management to determine the best path to reduce the chance of incidents and consider the improved performance of workers by providing a cooler atmosphere.