Heat illness prevention emergency regulation enforcement questions and answers

This standard applies in all outdoor places of employment at those times when the environmental risk factors for heat illness are present. (See Q&A No.s 4, 5, and 9 for a more complete explanation of the definition of “environmental risk factors for heat illness.”)

An outdoor place of employment is best thought of as one that is not an indoor workplace. A workplace with a roof and enclosed sides is generally considered an indoor workplace.¹

For the purposes of this standard, the important quality of indoor workplaces is that they modify the environmental risk factors for heat illness. For example, building codes require that buildings provide sufficient ventilation, either by natural or mechanical means. Indoor workplaces usually also block exposure to direct sunlight.

On the other hand, open areas like agricultural fields, forests, parks, equipment and storage yards, outdoor utility installations, tarmacs, and roads, are obvious examples of outdoor workplaces. Outdoor workplaces also include construction sites in which no building shell has been completed and areas of construction sites that are outside of any building shells that may be present. Outdoor areas adjacent to buildings, e.g., loading docks, will also be considered outdoor places of employment if an employee spends a significant amount of time working in those areas.

Sheds, packing sheds, and partial or temporary structures such as tents, lean-tos, and structures with one or more open sides can be either indoor or outdoor workplaces depending on the circumstances. In many cases these structures may actually be hotter than the environment outside of them because of heating by the sun and conditions inside like limited air circulation and/or lack of insulation. The Division will consider a structure in this category to be an outdoor workplace if it does not significantly reduce the net effect of the environmental risk factors that exist immediately outside of the structure.

Yes. They include requirements for employers to have an effective Injury and Illness Prevention Program and to provide for drinking water, first aid and emergency response. There are also requirements tailored to specific industrial operations.

IIPP. Title 8 CCR 3203 requires an employer to establish, implement, and maintain an effective Injury and Illness Prevention Program. All IIPPs must include effective procedures for hazard identification, evaluation and control, hazard correction, investigation of employee injuries and illnesses, and communication with employees about health and safety matters.

The requirement for effective communication is particularly relevant to heat illness prevention. In evaluating compliance with this requirement, the Division will determine what the employer does to account for the whereabouts of all employees at appropriate intervals during the work shift and at the end of the shift. This is a critical procedure to follow when the outdoor work environment creates a heat hazard that could result in the collapse of an employee due to heat illness.

Construction 8 CCR 1524

Hand labor in agriculture 8 CCR 3457

Mining 8 CCR 6975

All other places of employment 8 CCR 3363

These standards require provision of sufficient quantities of drinking water in general in any work environment to which they apply. For employees working in the heat, a minimum of one quart of drinking water per hour must be available to each employee, e.g., two gallons per employee for an eight-hour shift, to replace water lost by sweating.

Construction 8 CCR 1512

Agriculture 8 CCR 3439

Logging and sawmills 8 CCR 6251

Petroleum drilling and production 8 CCR 6511-6512)

Petroleum refining, transportation and handling 8 CCR 6767

Tunneling 8 CCR 8420-8421

Telecommunications 8 CCR 8602(e)

All other places of employment 8 CCR 3400

Hazardous waste sites and emergency response 8 CCR 5192

Working chambers subjected to compressed air 8 CCR 1230(a)

Ventilation. Building ventilation systems are regulated by 8 CCR 5142 and 8 CCR 5143.

Section 3395 defines environmental risk factors as including “air temperature, relative humidity, radiant heat from the sun and other sources, conductive heat sources such as the ground, air movement, workload severity and duration, protective clothing and personal protective equipment worn by employees.”

Some of these factors, such as air temperature, radiant heat, air movement and conductive heat sources determine how much a worker’s body is heated from external sources. Relative humidity, air movement, protective clothing, and some personal protective equipment affect a worker’s ability to cool through the evaporation of sweat and contact with cooler air. Workload intensity and duration, which can be increased by use of personal protective equipment, add to the worker’s heat burden by producing metabolic heat.

Judging by the time of year. In general, employers should assume that environmental risk factors for heat illness are highly likely to be present from the beginning of April through the end of October in most areas of California. Of course, the actual weather conditions, like temperature, humidity, and sunshine, are what determine the actual risk each day throughout the whole year.

Using the Heat Index. Employers may want to use the Heat Index, a number calculated by the National Weather Service to rate heat illness risk using temperature (in degrees F) and humidity.

The Heat Index chart can be found at http://www.crh.noaa.gov/dvn/tools/heatindex.pdf When you know the temperature and humidity, the chart easily allows you how to find the Heat Index, which is the temperature adjusted for the effect of humidity.

In general, employers should assume that there is a significant risk of heat illness for employees working in the sun if the Heat Index for the day is 80 or above. If employees will be working in shade, a heat index of 90 or above is the equivalent point of risk. This adjustment for work in the sun is critically important because the Heat Index you calculate from the chart is assumes a person will be working in the shade.

It is also necessary to account for the clothing workers are wearing. The Heat Index assumes people are wearing light summer clothing. When workers use heavier clothing, or use some types of personal protective equipment, the risk of heat illness becomes significant at a lower Heat Index.

The National Weather Service forecasts the temperature in various locations in California. Weather forecasts and information are broadcast on NOAA Weather radio and can be accessed at http://iwin.nws.noaa.gov/iwin/ca/ca.html.

Unfortunately, detailed weather information including humidity and heat index calculations are not available for many microclimates. If you are using current temperature and humidity reports from the National Weather Service or the media, keep in mind how your local area typically differs (for example, is it typically hotter or cooler, and if so by how many degrees?) from the area reported on. Keep in mind that the most reliable approach may be to take your own measurements of temperature and humidity and use the Heat Index to evaluate them. Simple inexpensive devices are available on the market that will measure temperature and humidity. These measurements should always be taken in the actual work area, with the device shaded. These do not provide sophisticated scientific measurements like the WBGT ², but they will suffice for the purposes of this standard.

Workers who use chemical protective clothing, such as hazmat suits that are meant to be impervious to chemical liquids and vapors, can be at risk of heat illness even when temperatures are mild. These workers should be included in a comprehensive heat stress-monitoring program.

In conditions of high heat and strenuous work, the human body can lose over a quart of fluid per hour just by sweating. Continuous replacement of this lost fluid is critical to preventing heat illness, and this means assuring the presence of, ready access to, and consumption of potable drinking water.

Where unlimited drinking water is not immediately available from a plumbed system, and the employer chooses not to provide the full-shift quantity of drinking water at the beginning of the work shift (2 gallons per employee for an 8-hour shift), the standard requires effective procedures for drinking water replenishment to allow employees to drink one quart or more per hour. This means that at all times there must be a sufficient quantity of water present and readily accessible to allow every employee to consume at least one quart of water per hour.

Any water supply procedure that depends on replenishment during the work shift will be out of compliance if it is not reliable. If employees cannot count on reliable replenishment of the water supply they will feel pressured to reduce their water consumption in order to conserve the supply. Employers will also be out of compliance if at any time no drinking water is available to employees, or if their practice is to wait until the water vessel is empty to replenish it. It is similarly impermissible for an employer to replenish the drinking water supply only when requested by employees.

Shade is blockage of direct sunlight. Shade can be provided by buildings, canopies, lean-tos, or other partial and/or temporary structures that are either ventilated or open to air movement. Trees can be used for shade as long as the cover provided by the trees blocks the direct sunlight.

Shade is sufficient when objects do not cast a shadow in the shaded area. An enclosed area used to provide shade must allow cooling comparable to that provided by shade in the open air.

Therefore, it is not permissible to use the interiors of cars or other vehicles for shade unless the vehicles are air-conditioned or kept from heating up in the sun in some other way. Similarly, metal storage sheds and other out-buildings do not provide protection from sunlight that meets the definition of shade unless they provide a cooling environment comparable to shade in open air. This means they must be mechanically ventilated or open to air movement.

The shaded area must also allow the employee to assume a comfortable posture and must not cause exposure to another hazard. Therefore, the shade requirement cannot be met by using areas underneath mobile equipment, like a tractor.

The purpose of the recovery period is prevention of heat illness. The employer is required to provide access to shade for those employees who believe they need a preventive recovery period from the effects of the heat and any who actually exhibit indications of heat illness.

Access to the shade must be permitted at all times, and the employee must be permitted to remain in the shade for a period of at least five minutes. The importance of prevention cannot be overstated. When employees wait until actual symptoms appear before seeking shade and recovery, they are at significant risk of developing serious heat illness and the purpose of the standard is defeated.

The purpose of the preventive recovery period is to reduce heat stress on the employee. Since people produce more metabolic heat while working, resting reduces this source of heat, and also reduces the heart rate. Water should be available in the recovery area to prevent further dehydration and enhance recovery.

The preventive recovery period is not a substitute for medical treatment. If an employee has any symptoms of heat illness, first aid procedures should be initiated. Common early signs and symptoms of heat illness include headache, muscle cramps, and unusual fatigue. However, progression to more serious illness can be rapid, and can include loss of consciousness, seizures, mental confusion, unusual behavior, nausea or vomiting, hot dry skin, or unusually profuse sweating.

Any of these symptoms require immediate attention. Even the initial symptoms may indicate serious heat exposure. If medical personnel are not immediately available on-site, and you suspect serious heat illness, emergency medical personnel should be immediately contacted. No employee with symptoms of possible serious heat illness should be left unattended or sent home without medical assessment and authorization.

See Q&A No. 4 and 5. It is up to the employer to develop effective procedures for identifying, evaluating, and controlling these risk factors in their workplaces. Generally speaking, the best starting place is to obtain the weather forecast, including temperature and humidity for the area of the worksite, or for the area closest to the worksite. This information can be confirmed by taking measurements of temperature and humidity at the worksite. The temperature and humidity can be evaluated with the Heat Index.

If actual temperature and humidity measurements are not used, it is important to take advantage of reasonably available information on how the area of the worksite compares to the area for which temperature and humidity are reported. For example, if information is published for an area that is typically cooler than the area in which employees are to be working, this should be taken into account where practicable.

Whatever method employers use to determine temperature and humidity, they must also take into account the work severity and duration at the worksite, the amount of exposure to direct sunlight, and the types of clothing and personal protective equipment used.

Depending on the operation, employers can control these risk factors through a variety of means. Providing shade for work areas, scheduling outdoor or vigorous work in the cooler parts of the day, scheduling additional breaks during the hot times of the day, providing misters and other cooling mechanisms, rotation of particularly hot jobs, and cooling vests are all effective measures some employers have taken to reduce the risk of heat illness.

In addition to having a strategy for dealing with environmental risk factors for heat illness, employees must be trained so that they understand the employer’s basic approach. The most successful employers make this training a matter of teamwork and profit from a team approach to making the system work.

In determining compliance, the Division will look to the content of information provided to employees about personal risk factors for heat illness and whether this information has been conveyed using methods of training generally accepted as effective. The standard does not require employers to get personal information from employees, and employers are neither expected nor encouraged to do this.

The Division believes that the intent of the standard is to ensure that employers provide employees with basic information about risk factors that may affect their vulnerability to heat illness, e.g., age, degree of acclimatization, health, water consumption, alcohol consumption, caffeine consumption, and use of prescription medications. With the exception of the length of time an employee has been working recently in high heat, which is an acclimatization issue, most employers do not have information about their employees regarding their personal risk factors for heat illness and are not expected to have it.

Many employers may have information available to them about their employees’ degree of acclimatization, because they know where their regular employees have been working and can ask new employees about where they have been working and what kind of work they have been doing recently. Training for employees must include the importance of acclimatization and how it is developed. Employers are encouraged to develop procedures to aid employees in becoming adjusted to work in the heat, such as modifying work cycles or limiting work in heat. It is important to exercise additional caution with employees when there is a heat wave, when new employees come onto a job site, and when employees return to work in heat after an absence lasting more than a few days.

The basic test of training is its effectiveness. The standard lists several items of training information content and the Division will evaluate compliance with the training requirements by looking at the content as well as the manner in which it has been presented.

Employers often make a common mistake after obtaining competent training content from a reputable source by failing to tailor the information so that it is applicable to the actual work situation of the employer and his or her employees. It is crucial that employers who wish to use a “one size fits all” product understand the information provided and make sure that they add and subtract what is necessary to make the information relevant to their individual work situation.

Cal/OSHA has often heard from employers that training must be frequently reinforced to be effective. Some employers recommend a daily “tailgate meeting” approach, where a brief safety reminder about issues considered particularly relevant to the work to be performed that day is given every day prior to starting work.

As part of its evaluation of compliance, Cal/OSHA personnel will ask a representative number of supervisory and non-supervisory employees questions about the required training elements. They will be asked questions to determine whether they have received training and whether they exhibit sufficient understanding of the training content to indicate that the information has been conveyed using training methods generally recognized as effective.

The intent of such questions is not to test for answers that are always correct, but to look for the indicators of effective training that come with a good faith and sincere effort to get across essential and complete information. In summary, the test of compliance with the training requirements of this standard will be whether the training has occurred, whether the required content has been provided, and whether the training has been effective overall in communicating the essentials to employees.

Emergency preparedness. Training must include the information necessary for effective emergency preparedness. This includes the procedures to be used in responding to an employee showing indications of heat illness, contacting emergency medical services, and providing directions to the work site. Where the workers themselves are not capable of communicating directly with emergency services and giving directions to their location, the employer must ensure that a designated person who can communicate is identified to employees and is immediately available to contact emergency services.

There are many publications and websites with information on heat illness. Cal/OSHA recently published a heat advisory that is available at: http://www.dir.ca.gov/dosh/heatadvisory.pdf.

The American Conference of Governmental Industrial Hygienists (ACGIH) has adopted detailed guidelines for prevention of occupational heat stress and heat strain based upon the WBGT. These guidelines can be purchased from ACGIH (www.acgih.org). See also Q&A No. 5 for information sources heat measurement and weather information.