Work week

Ozone s presence in the atmosphere (amounting to the equivalent of a layer 3 mm thick under ordinary pressures and temperatures) helps prevent harmful ultraviolet rays of the sun from reaching the earth s surface. Pollutants in the atmosphere may have a detrimental effect on this ozone layer. Ozone is toxic and exposure should not exceed 0.2 mg/m (8-hour time-weighted average - 40-hour work week). Undiluted ozone has a bluish color. Liquid ozone is bluish black and solid ozone is violet-black. 

It is very poisonous, 50 mg constituting an approximate fatal dose. Exposure to white phosphorus should not exceed 0.1 mg/ms (8-hour time-weighted average - 40-hour work week). White phosphorus should be kept under water, as it is dangerously reactive in air, and it should be handled with forceps, as contact with the skin may cause severe burns. 

Zinc is not considered to be toxic, but when freshly formed ZnO is inhaled a disorder known as the oxide shakes or zinc chills sometimes occurs. Where zinc oxide is encountered, recommendations include providing good ventilation to avoid concentration exceeding 5 mg/ms, (time-weighted over an 8-hour exposure, 40-hour work week). 

The U.S. Department of Labor (OSHA) has ruled that an employee s exposure to dimethyl acetamide in any 8-h work shift of a 40-h work week shall not exceed a time-weighted average of 10 ppm DMAC vapor in air by volume or 35 mg/m in air by weight (7). If there is significant potential for skin contact with DMAC, biological monitoring should be carried out to measure the level of DMAC metaboHtes in urine specimens collected at the end of the shift. One industrial limit is 40 ppm DMAC metaboHtes, expressed as AJ-methylacetamide [79-16-3] for individuals, and 20 ppm metaboHte average for workers on the job (8). 

The OSHA permissible exposure limit (11) and the American Conference of Governmental Industrial Hygienists (ACGIH) estabHshed threshold limit value (TLV) (12) for fluorides is 2.5 mg of fluoride per cubic meter of air. This is the TLV—TWA concentration for a normal 8-h work day and a 40-h work week. 

The 1994—1995 threshold limit values as recommended by the American Conference of Governmental Industrial Hygienists (ACGIH) are given in Table 8. These time-weighted average values are those levels to which nearly all workers may be exposed for an 8-h workday and a 40-h work week without adverse effect (99). 

Phenol fumes are irritating to the eyes, nose, and skin. According to the National Institute for Occupational Safety and Health (NIOSH), exposure to phenol should be controUed so that no employees are exposed to phenol concentrations >20 mg/m, which is a time-weighted average concentration for up to a 10-h work day, 40-h work week. Phenol is very toxic to fish and has a nearly unique property of tainting the taste of fish if present in marine... 

The U.S. Department of Labor (OSHA) has ruled that an employee s exposure to aniline in an 8-h work shift of a 40-h work week shaU not exceed an 8-h time-weighted average (TWA) of 5 ppm vapor in air. The American Conference of Governmental Industrial Hygienists (ACGIH) recommends a... 

Tb allium, which does not occur naturaHy in normal tissue, is not essential to mammals but does accumulate in the human body. Levels as low as 0.5 mg/100 g of tissue suggest thallium intoxication. Based on industrial experience, 0.10 mg /m of thallium in air is considered safe for a 40-h work week (37). The lethal dose for humans is not definitely known, but 1 g of absorbed thallium is considered sufficient to kHl an adult and 10 mg/kg body weight has been fatal to children. In severe cases of poisoning, death does not occur earlier than 8—10 d but most frequently in 10—12 d. Tb allium excretion is slow and prolonged. For example, tb allium is present in the feces 35 d after exposure and persists in the urine for up to three months. 

The adopted values for TWAs for airborne vanadium, including oxide and metal dusts of vanadium, is 0.5 mg/m the values for fumes of vanadium compounds is 0.05 mg/m. These limits are for normal 8-h workday and 40-h work-week exposures. The short-term exposure limit (STEL) is 1.5 mg/m for dusts (25). A description of health ha2ards, including symptoms, first aid, and organ involvement, personal protection, and respirator use has beenpubhshed (26). 

Table 9-63 uses the data of Fig. 9-44 to compare the relative fixed-capital costs for plant constnic tion in other countries with those for the United States. The relative cost ratios were developed from data similar to those in Table 9-62. Labor ratios were corrected for the different local rates and hours per working week, job duration, and degree of mechanization available in other countries. Some of these factors are difficult to estimate, and the final total ratios give a reasonable order-of-magnitiide value for relative construction costs for equivalent plants in the countries indicated.

Time-weighted average (TWA) TLV - the time-weighted average eoneentration for a normal 8 hr work day and a 40 hr work week, to whieh it is believed that nearly all workers may be repeatedly exposed, day after day, without untoward effeets. TWA TLVs permit exeursions above the TLV provided that they are eompensated for by equivalent exeursions below the TLV during the work day. The exeursion above the TLV is a rule of thumb, as explained in the souree referenee. 

Period Basic working week, e.g. <40 hr/wk, 48 wk/yr plus overtime therefore intermittent elimination and recovery times. Holidays excepted Continual unless area vacated therefore elimination and recovery depend on irregular periods of low/ zero concentrations... 

Time-weighted average concentration, TWA, based on a 40-hour work week. 

Extended working weeks of 60 hours or more were common in the nineteenth century, but for much of the twentieth century the norm has been a 5-day/40-... 

This increase in productivity is accounted for partly by a decrease in absenteeism and accidents as well as a general increase in working efficiency. For example, Vernon (1918), found that when women in a munitions factory worked a 12-hour day they incurred 2.5 times more accidents than when they worked a 10-hour day. One of the more comprehensive studies of the effects of total hours of work was carried out after World War II by the U.S. Department of Labor (Kossoris and Kohler, 1947). This covered over 3500 men and women in 78 work units. Data were collected on accidents and absenteeism as well as productivity. The overall findings were that exceeding the 8-hour work day, 5 days/40 hours work week resulted in lower productivity and higher absenteeism and accident rates. 

Voile, M., Brisson, M., Perusse, M., Tanaka, M., Doyon, Y. (1979). Compressed Work Week Psychophysiological and Physiological Repercussions. Ergonomics 22, 1011-1010. 

It should be noted that these are in terms of short-or long-term exposure levels and are based on an average working week s exposure and an average working life. They do not directly relate to exposure outside the workplace. 

Fixed overheads require some amplification. Budgeted output for the year is 400,000 units, budgeted fixed overheads for the year are 40,000. There are 50 working weeks in the year with 4 weeks in the period being reviewed, with one extra day being worked. The actual fixed overheads for the period amounted to 4,116. 

When there is a rapid increase in industrial and private building, construction labor is usually in short supply. Under these conditions companies must often guarantee two hours overtime per day and ten hours of overtime per week in order to get workers. All overtime is at least at the time-and-a-half rate, and usually anything over 50 hours per week is at double the base rate. For electricians, all overtime costs the company twice the usual rate. Under these conditions it was not unusual for a man in the building trades to earn over 500 per working week in 1972. 

Breathing rate for 8-hr work day)x(TLV)x(5 day work week) (Body weight)x(7 day work week)x(safety factor)... 

The federal government has developed regulations and advisories to protect individuals from the potential health effects of acrylonitrile in the environment. The U.S. Environmental Protection Agency (EPA) recommends that acrylonitrile levels in water not exceed 0.058 ppb. Any release to the environment of more than 100 lb must be reported to the federal government. The Occupational Safety and Health Administration (OSHA) has established a legally enforceable maximum limit of 2 ppm in workplace air for an 8-hour exposure over a 40-hour work week. 

WPL AEL Worker Population Airborne Exposure Limits developed for the military by the CDC. They are based on a time-weighted average exposure over an 8-h period and 40-h work week. 

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