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High temperatures and the rush of summer activity prompt many of us to think about problems that heat may bring. An early wave of hot weather and a few headline-making farm worker deaths already this year have intensified concerns about the most extreme hazards of heat to the human body. But heat can cause plenty of harm short of fatality, and not only in warm-weather seasons. It is a fact of life to deal with in fields, vineyards, orchards, nurseries, dairies, and many other types of workplace. With harvest work in full swing, California growers and workers are facing familiar heat-related challenges in a changed legal context. A permanent state regulation designed to reduce risks of heat illness in outdoor workplaces took effect in mid-summer 2006, adding to employers’ responsibilities for safe operation. While people in agriculture have long coped with heat in various ways, the new rule obligates all covered employers to take a specific set of measures to help workers control heat stress and get timely care when showing signs of heat-related illness. Cal/OSHA has noticeably stepped up enforcement of its requirements this year. So besides their employees’ and own exposure to the old risks of heat build-up causing discomfort, illness, injury, operational disruption, and insurance premium bumps, agricultural employers are now subject to penalties for not meeting terms of the relatively new standard. Regardless of any legal mandates, most managers can and are behooved to help workers minimize the impacts of heat stress. Simply keeping the igloos full and reciting the familiar litany of advice to drink lots of water, beware of stress symptoms, and rest when necessary goes only so far. How Heat Hurts Humans are capable of performing work under a wide range of conditions as long as their internal organs and biochemical reactions are doing well, which depends on their temperature being within a narrow range around 98.6-degrees. When bodies get too cool or warm, natural processes that add or release heat kick in to restore the norm. Although “feeling hot” causes discomfort and distraction, the very process of cooling often gives rise to greater dangers. Heat stress tends to be more of a problem when the weather is hot, but high ambient temperature is not its primary cause. While some of the heat that farm workers have to deal with comes from solar radiation and hot air in their midst, most of it is produced within their own bodies. The body’s metabolism generates some heat even at rest, and when it speeds up to convert energy faster during physical work, its yield of heat as a by-product also increases. Roughly three to four times as much of this converted energy turns into heat as to motion. Heat that accumulates in the body raises internal temperature, threatens normal functioning, and triggers dissipation mechanisms. Though internally generated heat can stress people in almost any environment, it is more difficult to release where the air is hot, humid, or still. Both retained heat and the body’s attempts to shed it can eventually cause symptoms recognized as a “heat illness” that impairs physical or mental activity, reduces performance, increases risk of accidents, and endangers life. Heat stroke, the most serious such illness, is a medical emergency. Although less critical ailments -- heat exhaustion, heat syncope (fainting), heat cramps, and heat rash -- are not immediately life-threatening, they reduce well-being and performance and can progress to stroke if not treated. Click here for an article that describes common symptoms of and treatment guidelines for these illnesses. Even pre-illness effects of excess body heat and the loss of fluid through sweating may cause damage. Subtle discomfort, weakness, blurred vision, slowed reactions, diverted attention, lapses in concentration or judgment, reduced coordination, and irritability add to chances of workers doing things that not only hurt themselves but also translate into higher production costs. Heat stress is probably under-credited as a factor contributing to such incidents as falling off a ladder, cutting a finger, driving a tractor into a ditch, mis-calibrating a chemical solution, and picking a fight. How do these symptoms develop? When metabolism generates heat faster than needed, adjustments begin in the circulatory system. The heart pumps faster and blood vessels dilate (i.e., expand) to bring more blood to surface layers of skin, from which the heat it carries is conducted, convected, and radiated to the cooler environment. If a body cannot cool fast enough this way alone, or when the air is warmer than the skin, it resorts to sweating, its most efficient means for dissipating heat. Sweat glands draw water from the bloodstream, carrying heat, and send it through pores onto the skin surface, from which the heat transfers more easily to the surrounding air. The evaporation of sweat (turning it from liquid to gaseous state) consumes energy, so it also has a slight cooling effect on the air adjacent to skin surface. The higher the humidity, however, the slower the evaporation and the less it contributes to cooling. These mechanisms are not without cost to other bodily functions. Increasing flow of blood to the body surface reduces the volume available to carry oxygen and nutrients to muscles, the brain, and other internal organs, which in turn impairs strength, diminishes alertness, and accelerates fatigue. Moreover, the loss of fluid from blood volume through sweating reduces the body's ability to cool itself and perform work later, and the related depletion of electrolytes carried out in sweat can touch off muscle cramps. The longer that sweating goes on, the less blood volume there remains to circulate and the greater the risk of experiencing symptoms of heat illness. A 150-lb. man performing moderately active work in warm weather, for example, would lose about 3/4 quart of water, or 1% of his body weight, per hour. At that rate, if not replacing any of the lost fluid he would likely feel notable loss of energy and endurance after three hours, have serious fatigue and nausea after six, and lose consciousness after eight. Keys to Prevention Research in sports, exercise, military and industrial settings has yielded lessons about heat stress that are very applicable to agricultural workplaces. Not surprisingly, the single measure that these studies suggest as most important for reducing risks of heat stress is to steadily replenish the fluid that the body loses as sweat. Because thirst signals a water deficit only after it begins to affect performance, starting to drink based on knowledge and anticipation is safer than waiting to feel thirsty. Chugging to quench an intense thirst is no more timely than pouring water on a wilted plant. The amount of water needed to replace loss through sweating is a function of workload, weather, and personal physical attributes. A U.S. Army guide recommends drinking one quart per hour when performing hard work and wearing protective gear in 90+ degree temperatures, about ¾ quart when doing moderate work in temperatures of 82-90 degrees. This reference also suggests resting for substantial portions of each hour in those conditions, so as to slow the metabolic generation of additional heat as the body releases its accumulated excess. Few businesses can provide as much break time as the fully loaded soldier needs, but all can strive to help workers follow the advice to drink. At most agricultural workplaces, water is provided in an “igloo” container available to employees throughout the day. My observations from conversations with numerous managers and two field studies, however, are that production workers in strenuous activity tend to visit the igloo infrequently, when quite thirsty, and that they drink large quantities on each visit, all resulting in a low volume and poor rate of fluid replenishment over the course of the day. When workers do not drink as much or often as they need, it is typically due to some combination of their undervaluing the replacement of lost body fluid and experiencing high “costs” to obtain the water that is provided. Costs or impediments to access the igloo include physical effort, supervisory or co-worker disdain, foregone earnings opportunity when on piece-rate pay, and the chance of ingesting microbes (wariness perhaps based on experience with non-bottled water in another country). For managers as well as workers, putting too low a priority on fluid replacement may stem from limited knowledge of how the body generates and copes with internal heat. Many people feel thirst after their fluids are somewhat depleted but do not suspect the connection between inadequate hydration and other early, non-specific symptoms of heat illness. Without understanding the reasons behind exhortations to drink water frequently, workers are neither as equipped nor as motivated as they could be to do their part in combating heat stress, and supervisors are less apt to assist them with logistical support, information, and personal example. Basics of the Heat Illness Prevention Standard The regulation that now obligates employers to take certain heat illness prevention measures entered the California Code of Regulations on July 27, 2006, as section 3395 of Title 8, Chapter 4, Subchapter 7, Group 2, Article 10. The Heat Illness Prevention (HIP) standard applies to all outdoor workplaces in California, all the time. In brief, it requires employers of people who work outside to provide four things:
Definitions in the regulation text and interpretations in a Q&A document from Cal/OSHA elaborate on these requirements and instruct enforcement personnel. Regarding the water, unless a plumbed or other continuous supply is readily available to workers, the whole amount is to be provided in portable containers either at the beginning of the shift or in stages through a reliable system of replenishment that allows all employees to drink at least one quart per hour. Employers are considered out of compliance if at any time no drinking water is available, or if the replenishment practice is to wait until either the container is empty or employees request more water. Cal/OSHA sees a replenishment system as unreliable if employees feel pressured to reduce their water consumption in order to conserve for later in the day. Shade, according to the regulation, is blockage of direct sunlight. It can be effected by buildings, canopies, awnings, “pop-up” or other temporary structures, and even trees. One indicator of blockage adequacy is that “objects do not cast a shadow in the area of blocked sunlight,” but a shaded area that is too hot to allow the body to cool does not pass muster. Access to the shade is to be permitted at all times to any employee “suffering from heat illness or believing a preventative recovery period is needed” (including before the onset of any symptoms). The regulation spells out topics for the content of training. While it does not similarly specify training methods, Cal/OSHA says that evaluation of compliance will also depend on manner of presentation, and that enforcement personnel will quiz employees in assessing whether an employer has made a good faith effort to convey essential content. The topics required in training for all employees are:
Two more to cover with supervisory employees are:
Finally, the documentation of compliance and response procedures is to be made available to employees and to enforcement personnel upon request. It may be kept as a stand-alone policy but probably is best integrated into the employer’s overall written injury and illness prevention program. The permanent standard and the temporary regulation that preceded it in 2005 have been enforced both through Cal/OSHA inspections, many driven by complaints and accident reports, and through area-industry sweeps by the state Economic and Enforcement Employment Coalition (EEEC). The violation most commonly cited this year is lack of a written compliance plan, which previously ran second to failure to train employees. Intensified enforcement since 2007 has targeted areas at times when they are forecast to have heat waves. Meeting Challenges on the Ground Like most laws, the HIP regulation applies to people in a broad range of circumstances. It is a rather blunt instrument, not tuned to differences between outdoor industries or across agricultural sectors, places, and time. While based on sound principles, the measures prescribed by section 3395 make a lot more sense in some outdoor work situations than others. Neither the shepherd in December nor the vine trainer in April, for example -- to say nothing of the San Francisco hotel doorman or Tahoe ski-lift operator in February -- has the same needs to cool, to drink, and to know about heat stress as the onion topper and melon harvester in August. Nevertheless, the regulation exposes employers to legal risks that can only be controlled by attending to its terms. Achieving its fundamental purpose is another matter. Complying with rules of the state hardly assures success in contending with physiological processes. Even dutifully following HIP requirements where and when they are appropriate cannot eliminate the chances of workers being harmed by heat. Minimizing that kind of risk depends on managers, first-line supervisors, and workers themselves making good decisions within the legal bounds. Controlling heat stress is a team sport. Managers have various choices that affect workers’ inclination to drink and rest as needed, and many now make them with eyes on both the purpose and letter of the law. I have seen and heard about creative adjustments in the provision of water, shade, and education that help workers to make and act on their own risk-reducing decisions. They often amount to improving access. The distance that agricultural employees have to walk from where they are working to the water container varies with differences in field layout, proximity of equipment used in tasks being performed, and directions given by employers. During grape harvest, for example the igloo is usually attached to a tractor or gondola only a few strides away, and in vine training and other row operations that involve no machines it may sit in a truck or at end of a row far from the action. A north coastal vineyard operator has modified the metal igloo cradle that normally attaches to a gondola during harvest so that it can be removed easily and placed to stand freely in the row and serve workers when the full gondola departs. So while workers await the next (empty) gondola, the igloo remains continuously available, and they take good advantage of it. A central valley labor contractor in row-crops has reduced workers’ cost of access to drinking water without any such bar bending or welding. He simply instructed each crew leader to frequently drive the igloo-carrying, toilet-toting pickup truck closer to the workers as they eased farther from the day’s starting point, and he explained why. His basic idea has broad applicability, as there are often opportunities for supervisors to move the water closer to workers’ current center of activity as they progress through a field. If managers explain that they want foremen to place and keep the water as close as possible, and why, workers will end up with less of a physical price to pay for going to it and probably less concern about supervisory scorn as well. Growers and contractors have purchased assorted pop-up canopies, umbrellas, and camp awnings to provide portable shade. Some have fashioned awnings that attach to trucks or other equipment. The principal of a large labor contracting firm based in the southern desert region has literally raised shade to a new level by adapting a one-axle trailer that integrates two large fold-up shade screens, a table, igloo frames, and a stack of plastic chairs. Most of his crews are outfitted with one of these portable structures, and on warm days workers spend all or most break time in the shade it creates. More important, some crew members spend much of their work time in the shade of a tarp stretched over the full width of the field packing machine at the center of their melon harvest. Knowledge of some basic physiological principles is needed up and down the line to inform choices that protect against harm from heat while fitting with other business objectives. Since agricultural workers are just as inclined as anyone else to make reasonable decisions based on what they know, managers can effectively support workers’ day-to-day control of risks by helping them understand the causes, consequences, and autonomic responses to heat stress. Click here for a list of ten key points that I suggest trying to convey by whatever means possible. They can be delivered and discussed in orientations, tailgate meetings, and company handbooks. A two-sided, bilingual folding heat stress information card, the English side of which may be downloaded here, is designed for distribution to employees at meetings or in paycheck envelopes. Many other references and field training tools are available from grower organizations, Cal/OSHA, and UC-DANR. Growing and Pruning Uncertainties In wake of the highly publicized fatalities and reports of several more heat-related cases early this summer, Cal/OSHA has launched a wave of informational outreach and enforcement activity that focuses on the requirements listed in the heat illness prevention standard. It remains to be seen whether this campaign will allay more concerns than it raises about agency efforts’ consistency with the regulation itself and about employers’ exposure to penalties for purely technical violations. The very notice from the Department of Industrial Relations (July 9) inviting farm labor contractors to a series of training programs specifically designed for them has caused some confusion. Though stating that participation is not a legal requirement and does not substitute for the annual 8-hours of continuing education needed to renew an FLC license, the notice is on the DIR Director’s letterhead, it promises attendees a proof of completion, and it says that ag groups will strongly encourage growers to ask for this proof. So inferences by growers and FLCs alike that they are now faced with yet another mandate, though mistaken, should not be astonishing. Each part of the rule leaves room and need for interpretation. Among questions of practical significance to which employers continue seeking answers are:
To my reckoning, the most consequential element of the HIP standard is the training requirement. And it is also the element most open to options on how to comply, despite its specificity about topics to cover. By what methods is training to be provided? By whom? Where? When? To what depth? Using what materials? None of these has a universally right answer, of course, and each could be the subject of an entire article. No matter how Cal/OSHA administers the new regulation, there is no substitute for exercising informed personal judgments at managerial, supervisory, and production crew levels. Managers do well for their businesses as well as their crews when they consider environmental conditions and physical demands of jobs in scheduling work, make access to the igloo as easy as possible, and patiently explain why frequent visits to it are a good idea. The array of references and instructional aids for workplace education about heat stress physiology has expanded in recent years. Much can be gained by drawing from it to give workers and supervisors with substantial knowledge rather than a mechanical recitation of cautions, commands, and assorted mantras. Everybody in an agricultural production business is better off when all join in understanding and battling heat stress. |
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