Heat stress

weight, degree of physical fitness, degree of acclimatization, metabolism, use of alcohol or drugs, and a variety of medical conditions, such as hypertension, all affect a person s sensitivity to heat. However, even the type of clothing worn must be considered. Prior heat injury predisposes an individual to additional injury. It is difficult to predict just who will be affected and when, because individual susceptibility varies. In addition, environmental factors include more than the ambient air temperature. Radiant heat, air movement, conduction, and relative humidity all affect an individual s response to heat. 

There is no OSHA regulation for heat stress. The American Conference of Governmental Industrial Hygienists (1992) has stated that workers should not be permitted to work when their deep body temperature exceeds 100.4°F. 

The main complications that transpire when workers suffer from heat exposure are 

Heat stroke, which occurs when the body s system of temperature regulation fails and body temperature rises to critical levels. This condition is caused by a combination of highly variable factors, and its occurrence 

In heat collapse (fainting), the brain does not receive enough oxygen because blood pools in the extranities. As a result, the exposed individual may lose consciousness. This reaction is similar to that of heat exhaustion and does not affect the body s heat balance. However, the onset of heat 

weight, degree of physical fitness, degree of acclimatization, metabolism, use of alcohol or drugs, and a variety of medical conditions, such as hypertension, all affect a person s sensitivity to heat. However, even the type of clothing worn must be considered. Prior heat injury predisposes 

OCCUPATIONAL HEALTH AND SAFETY MANAGEMENT A PRACTICAL APPROACH 

Heat rashes are the most common problem in hot work environments. Prickly heat manifests as red papules and usually appears in areas where the clothing is restrictive. As sweating increases, these papules give rise to a prickling sensation. Prickly heat occurs in skin that is persistently wetted by unevaporated sweaf and heat rash papules may become infected if they are not treated. In most cases, heat rashes will disappear when the affected individual returns to a cool environment. 

Three main conclusions resulted from the study. First, glutenin in the line with the Glu-Dld allele (HMW-GS 5+10) began to polymerize at an earlier time (by 3-6 days) than the line with the Glu-Dla allele (HMW-GS 2+12) and reached a higher value of UPP at maturity. Second, the application of heat stress caused a decrease in UPP and thus in MW 

How does the magnitude of change in dough strength compare between the effects of (a) deletion of one HMW-GS and (b) allelic variation from HMW-GS 5+10 to HMW-GS 2+12 at Glu-Dl Use data from Lawrence et al. (1988) and Gupta and MacRitchie (1994) to attempt to answer. 

What can be deduced about the ratio of LMW-GS/gliadins at the Gli-Bl/Glu-B3 locus of the parent lines from Table 11.4  

Lukaszewski, and G. M. Banowetz. 1997. Effect of Glu-Dl (5+10) on gluten strength and polymeric protein composition in durum wheat. Cereal Foods World 42 610. 

Blumenthal, C., E. W. R. Barlow, and C. W. Wrigley. 1993. Growth environment and wheat quality The effect of heat stress on dough properties and gluten proteins. Journal of Cereal Science 19 3-21. 

---

Heat. Personal monitoring of the environmental conditions which impose a heat stress on a worker is impractical, so fixed station measurement of such parameters as wet bulb globe temperature are usually made (see Temperature measurements). These stations are carefully selected so that the results, plus worker location and workload data, can be combined to yield an overall heat stress estimate. Heat strain, the effect on the human, can be estimated from core body temperature, but this is usually only a research tool. 

Ultrasonic (processes) Process which utilizes specially designed tooling usually vibrating at 15-80 KHz. Processes are designed to cause localized heating of thermoplastic materials which, in turn, will provide some type of welded or fused joint. Benefits are elimination of fillers and minimized heat stress on surrounding materials. 

Although heat-related disorders ean oeeur in a variety of work environments, heat stress and heat-related illnesses are an espeeially diflfieult situation to handle on eonstruetion sites. These heat-related disorders beeome more diffieult when working with hazardous materials, partieu-larly when workers are required to wear speeialized personal proteetive equipment (PPE). Under other eonditions workers may have a potential to eneounter high levels of radioaetive materials mixed with hazardous material (termed mixed waste ). Although mixed waste has been found in a variety of industries, it is eonsidered somewhat unique to Department of Energy (DOE) sites. [1]... 

Equipment may get washed with a steam jenny and allowed to air dry on plastic in a more remote area. We need to keep in mind that steam cleaners have the potential to cause substantial physical harm. The combination of high-pressure water and high temperatures can be dangerous. Wlien this is coupled with a worker standing on visquine or plastic, it becomes a slip, trip, and fall situation. Situations compounded with respiratory and whole-body protection, such as saranex or rubber suits and gloves, add in the potential for poor vision, heat stress, and the lack of physical dexterity. Keep these issues in mind prior to steam cleaner activity. 

Working in level A proteetion ean eause a variety of stresses. The equipment is heavy. The pressure to eomplete work tasks during a time frame is intensified beeause work time is limited by air supply. Heat stress ean be a problem, even in the winter. In the summer, the use of eooling vests ean keep you eool but also adds to the weight that you are earry-ing. Typieally, all level A workers have a sharp knife blade so that they ean eut themselves out of the suit if the air supply fails. Realizing that you may have to eut yourself out of this suit in ease of air supply failure adds more potential stress to the situation. 

However, after becoming familiar with site hazards as best as one can, along with analytical data, the level of protection shonld be reexamined. This reexamination shonld be bnilt into the plan, and specific criteria for downgrading levels of protection or the type of protective eqnipment shonld be considered. Even a downgrade in the type of coveralls reqnired can make a large difference in worker heat stress load. The ability of tyvek to breathe (as opposed to saranex) is very desirable when considering worker comfort and heat load. These options, and when they become viable, shonld be anticipated beforehand and placed in the SSAHP. 

For example, for a eaustie spill response performed by employees on site, the log indieated that one worker experieneed heat exhaustion during the eleanup and was absent from work the next day, likely due to heat exhaustion from the eaustie spill. No other entries in the log dis-eussed the use of heat stress monitoring or prevention praetiees, suggesting that sueh praetiees were not always implemented on the site. 

The heat stress plan at Site F detailed methods for monitoring workers heart rate and oral temperature, but did not designate the personnel responsible for performing sueh monitoring, nor did it inelude information about the availability or loeation of instruments for aetually monitoring sueh parameters. In addition, the plan did not identify or diseuss the loeation and availability of drinking water. 

The heat and eold stress program in the eontraetor s SSAHP at Site B appeared to be a statement of eorporate poliey and eontained no details about site-speeifie heat stress or eold stress program proeedures at the site. The SSAHP for Site J did not appear to have established heat stress SOPs, but indieated that workers should evaluate how they were feeling. The SSAHPs for Sites D and I had no diseussion of heat stress. 

The eontraetor SSAHP at Site A provided for heat stress monitoring to begin when the temperature rose above 70 degrees F. The OSC at this site indieated that this rarely happens during the summer months, and, thus, heat stress monitoring had not been eondueted. 

The audit indieated that heat stress programs were generally ineluded in most sites that were audited. The diflfieult part again appears to be in exeeution of the SSHAP, although, in some eases, no provisions were ineluded in the plans for heat/eold stress. 

Engineering Controls, Work Praetiees, and Personal Proteetive Equipment for Employee Proteetion Monitoring Deeontamination Emergeney Response Heat Stress Program Hotwork Fire Prevention and Proteetion Loekout/Tagout Confined Spaee Program Ineinerator Proeess Safety... 

Are employees familiar with medieal surveillanee requirements and reeognition of signs and symptoms that indieate overexposure to hazards (ineluding signs and symptoms of heat stress) [OSHA Referenee, 120(e)(2)(vi)]... 

Appropriate medical considerations, such as limitations during temperature extremes and potential for heat stress [OSHA Reference, 120(x)]... 

Is PPE selected and used to protect employees from the hazards and potential hazards they are likely to encounter as identified during the site characterization and analysis (including physical hazards such as heat stress, ionizing radiation, and noise) ... 

Does the site safety and health officer have the authority to downgrade the required level of PPE, when it is safe to do so, to reduce the potential for heat stress ... 

Has the employer implemented the use of engineering controls, work practices, and personal protective equipment to reduce and maintain employee exposure to or below published exposure levels for hazardous substances and health hazards not regulated by 29 CFR Part 1910, Subparts G and Z (e.g., heat stress, lifting hazards) [OSHA Reference. 120(g)(2)]... 

Does the potential for heat stress appear to have been considered in the selection of PPE ... 

Hazardous Waste Compliance Heat Stress Program... 

Is there a written heat stress prevention program as part of the SAHP or safety and health SOPs ... 

Provision for seleeting appropriate PPE to minimize the risk of heat stress ... 

Biologie monitoring for signs of heat stress (ineluding pulse rate, oral temperature, and/or blood pressure measurements) ... 

Has the employer implemented a heat stress training program ... 

Does the employer regularly monitor heat eonditions (i.e., dry bulb or adjusted dry bulb temperatures) to determine the risk of heat stress and to establish appropriate work/rest regimens (Note Wet bulb globe temperature is not the most appropriate measure of environmental heat eonditions when employees are wearing vapor impermeable proteetive elothing.)... 

Does the employer monitor the temperature, blood pressure, and pulse rate of employees exposed to heat stress environments ... 

Do the employer s OSHA 200 Log and OSHA 101 forms indieate any heat stress problems ... 

Does the personal proteetive equipment seleeted for employees in the exehision zone take aeeount of the need to reduee heat stress while also providing proteetion from ehemieal and other hazards at the site Are work operations seheduled to avoid physieally demanding work during periods of extreme heat ... 

Is a work/rest regimen regularly followed when work must be performed under eonditions of heat stress Are employees regularly notified of the work/rest regimen and any ehanges in that regimen ... 

The primary limitation of a HAZOP study is the length of time required to perform it. Because the study is designed to provide a complete analysis, study sessions can be intensive and lii ing. HAZOP studies typically do not look at occupational hazards (e.g., electrical equipment, rotating equipment, hot surfaces) or chronic hazards (e.g., chronic chemical exposure, noise, heat stress). For experience with HAZOP see Swann (1995). 

ISO EN 7243 Diagnostic method for hot environments Hot environments Elstimation of the heat stress on working man, based on the WTlGT index (wet hulb globe temperature... 

The WBGT heat stress index is calculated inside buildings and outside buildings without solar load as... 

The second method is by use of the heart rate. The total heart rate is regarded as a sum of several components and, in general, is linearly related to the metabolic heat production for heart rates above 120 beats per minute. Heat stress will, however, also increase the heat rate. The third method is to calculate the metabolic heat production from measures of oxygen consumption, and carbon dioxide production during activity and recovery. 

---