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Lead exposures from paint sanding and chipping during ship overhaul were evaluated. Several hundred workers were included in the study. Lead concentrations in 275 bulk paint samples ranged from 0.03% to 17.0% with a 0.25% geometric mean. The geometric mean air lead concentration was 61.0 micrograms/m3 when these paints were sanded and 2.4 micrograms/m3 when they were chipped. Air lead concentrations exceeded the Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) when paints containing as little as 0.2% lead were sanded but did not exceed the PEL or the action level when paints containing up to 6.0% lead were chipped. Poor correlation was found between paint lead contents and air lead concentrations for sanding (r = -0.27) and for chipping (r = 0.44). Similarly, poor correlation was found between air lead concentrations and blood lead levels for sanding (r = -0.14) and chipping (r = 0.24). Despite higher air lead concentrations, sanders' blood lead levels were not elevated compared with chippers and were only slightly elevated compared with non-lead workers. An extensive blood monitoring program was found to be particularly effective in assessing lead exposures and uptake while air lead monitoring was of limited value because of the high variability in air lead concentrations and in the nature of the sanding and chipping work during the overhaul. Lead-worker training was felt to be a particularly effective control measure. Blood samples collected toward the end of the overhaul revealed that blood lead and zinc protoporphyrin levels were not rising as the overhaul progressed and neared completion.

To evaluate patterns of occupational exposure to styrene monomer in the boat-building industry, we conducted industrial hygiene surveys in seven fiberglass-reinforced plastic boat-fabrication plants. A total of 397 personal breathing zone air samples were collected on workers in four key job categories: gel coating and hull, deck, and small-parts lamination. We found that exposure to styrene in 234 (59%) of the personal samples exceeded the NIOSH-recommended time-weighted average (TWA) standard of 50 parts per million (ppm), and 96 (24%) of these samples exceeded the OSHA eight-hour TWA permissible exposure limit of 100 ppm. From highest to lowest average exposure potential, the job categories ranked in the following order: hull lamination (range 2-183 ppm, mean 78 ppm), deck lamination (range 12-160 ppm, mean 73 ppm), gel coating (range 5-94 ppm, mean 48 ppm), and small-parts lamination (range 9-130 ppm, mean 45 ppm). The former two categories composed a higher-exposure group, and the latter two tended to form a lower-exposure group. Exposures in these jobs appear to be proportional to resin consumption. Statistical analyses indicated that the parameter that most affects exposure potential is job category. Within a job category, part size, configuration, and surface area are important determinants of exposure. The principal reason for high exposures was the absence of control technologies and, in particular, the absence of adequate ventilation.

A passive sampling device based on the principle of diffusion has been developed for the determination of formaldehyde in ambient air. The sampler consists of a capped glass tube (with approximate dimensions of 2.4 × 9 cm) containing a glass-fiber filter treated with NaHSO3. In the field, the device collects a sample by being uncapped for a specified sampling time. After being recapped and returned to the laboratory, the filter is analyzed by the chromotropic acid (CTA) method. Laboratory validation studies were conducted by exposing the sampling devices for 1 week to dry formaldehyde gas generated by passing trioxane vapor over an acid catalyst bed. In these tests, formaldehyde concentrations ranged from 0.05 to 0.80 mL/m3. Reproducibility was excellent, with relative standard deviations averaging 5.4% for five constant concentrations. The lower detection limit was determined to be 3.6 mL/m3 h. In an occupational environment an 8-h sample would be sufficient to detect compliance with the OSHA permissible exposure limit of 3 mL/m3; in a residential environment a 1-week sample would allow detection of 0.025 mL/m3 for indoor air quality audits.

The most important sources of thallium pollution are gaseous emission from cement factories, coal burning power plants and metal smelters. Inhalation and consumption of home‐grown vegetables and fruits are the major routes of thallium intake. Absorption occurs in gastro‐intestinal tract followed by ingestion in respiratory tract caused by intratracheal infection. Highest concentration is attained in renal medulls of kidney. The normal dietary intake of adults has been estimated at ∼2 μg/day whereas average excretion of T1 is ∼ 1 μg/day. Thallium is excreted both in animal and men through kidney, intestine and in small parts via hair and milk. The concentration of thallium in urine and hair is taken as an indicator of internal exposure; permissible exposure limit is O.1 mgTl/m3. Once distribution is complete, thallium is slowly mobilized from its intracellular compartment with a total body half life of approximately 30 days. The determination of sub micro and micro‐gram quantities of thallium is described ...

Quantitative evaluation of worker exposure to silica in nine Standard Industrial Classification (SIC) codes was conducted, using data derived from OSHA compliance inspections, in order to assess the silica exposure problem in the U.S. The nine SICs studied were those in which OSHA inspections were concentrated. They include: construction; chemical manufacture; stone, glass, and clay manufacturing; primary metal industries; metal fabrication; machinery; transportation; and miscellaneous manufacturing industries. High exposures to silica were documented in each industry, with the number of test samples over the permissible exposure limit ranging from 14% (aluminum foundries) to 73% (pottery). An estimation is made that 24,889 workers employed in ferrous and nonferrous foundries are at risk of silica-related pulmonary effects. The data developed in this analysis also indicate the need to investigate certain industries that had high exposures but few inspections. The limitations of the data base for estimating the scope of the silica problem, including lack of data on mining and milling, are discussed. We conclude that exposure to silica represents a continuing and significant problem in a number of U.S. industries.

Development of air purifying respirators for protection against ozone has been slowed by concerns about oxidation of charcoal and other available sorbents. The suitability of a charcoal sorbent for low concentrations of ozone was evaluated as a part of the development of a half-mask air purifying respirator designed for welding fumes and ozone. Testing of the respirator confirmed that charcoal can be a suitable sorbent for low levels of ozone. Where the respirator is properly selected, fit tested, and worn, respirator use against welding fumes and ozone at concentrations not exceeding 10 times the permissible exposure limit had been recommended.

The OSHA standard for coke oven emissions, which went into effect in January 1977, sets a permissible exposure limit to coke oven emissions of 150 micrograms/m3 benzene-soluble fraction of total particulate matter (BSFTPM). Review of the epidemiologic evidence for the standard indicates an excess relative risk for lung cancer as high as 16-fold in topside coke oven workers with 15 years of exposure or more. There is also evidence for a consistent dose-response relationship in lung cancer mortality when duration and location of employment at the coke ovens are considered. Dose-response models fitted to these same data indicate that, while excess risks may still occur under the OSHA standard, the predicted levels of increased relative risk would be about 30-50% if a linear dose-response model is assumed and 3-7% if a quadratic model is assumed. Lung cancer mortality data for other steelworkers suggest the predicted excess risk has probably been somewhat overestimated, but lack of information on important confounding factors limits further dose-response analysis.

A mathematical model is used to predict relative body burdens of inhaled contaminants in workers who work two jobs or overtime, or who experience off-the-job exposure to air contaminants. Expected “peak” or maximum body burdens from multiple exposures are compared to those expected from the “normal” occupational exposure on which TLVs and Permissible Exposure Limits (PELs) are based (five 8-hour days per week with zero off-the-job exposure). The model is designed to predict what adjustments to the TLVs and PELs are necessary to avoid accumulation of excess peak body burdens of contaminants from the additional exposures incurred. The general application of models to determine occupational exposure limits is reviewed, and several models are compared.

Passive dosimetry has considerable advantages over active sampling for monitoring exposures to ethylene oxide (EtO), including reduced complexity, reduced cost, and increased sample stability. The major disadvantage of these methods is the conflicting data currently being reported in the literature regarding their ability to meet Occupational Safety and Health Administration (OSHA) method accuracy requirements at the 1 ppm permissible exposure limit (PEL). A field validation study was performed to determine the accuracy of three EtO passive dosimeters (3M-3550®, DuPont Pro-tek,® and AMSCO EO-Self-Scan®) and a common active method (Qazi-Ketchum [QK]) as area samples at four unique concentrations inside a hospital products sterilization facility. Collected at each location were 12 dosimeters of each type along with 12 QK tubes and hourly Tedlar® bag grab samples analyzed by gas chromatography with flame ionization detection (GC-FID). To enhance the strength of this study, manufacturers of EtO dosimeters wer...

In order to determine the particulate exposure levels within carbon black production plants, a sampling survey involving workers from seven carbon black producers was initiated in late 1979. A total of 1,951 acceptable samples (1,564 total dust and 387 respirable dust) were collected from closed-face filter cassettes worn by carbon black workers performing normal work operations. A one-centimeter cyclone separator was employed for respirable dust sampling. Overall sampling distributions of the time-weighted average values generated from the survey were best described by the log-normal distribution. Characterization of the particulate exposures to workers is provided for the various areas of employment and specific jobs within these areas. Summary geometric mean time-weighted average values by area of employment and by job category are well within the carbon black permissible exposure limit (PEL) of 3.5 mg/m3. Identification of those job categories subject to relatively higher particulate exposures, and quantification of these exposures, is essential to the effective industrial hygiene monitoring and control of worker exposures.

OSHA's risk assessments, made in support of new standards, implicitly assume that workers are exposed at the level of the PEL on the average over their working lifetimes. This approach seems to be justified at least in cases where the toxicant is eliminated slowly from the critical site in the body. Thus, there are situations where the industrial hygienist should seek to evaluate worker mean exposure overtime. A simple testing procedure is proposed for determining whether the mean exposure of a lognormally-distributed exposure series, mu c, is less than the Permissible Exposure Limit (PEL) at desired levels of significance and power. With the assumption that the exposures are described adequately by a longnormal distribution, the method allows realistic exposure scenarios where mu c less than PEL to be declared acceptable with between two and fifty 8-hr TWA measurements, depending upon the value of muc and the level of variability. Application of the methods to three industrial data sets indicates that the approach is viable.

Commercial carbon black is a high purity material consisting of more than 99% colloidal carbon. It differs from environmental soots in that the latter are uncontrolled mixtures of various forms of particulate carbon and relatively large amounts of organic tars, resins, and inorganic salts and oxides. Carbon black is considered to be a suspect carcinogen by incorrect analogy with high-extract soot and because it contains polynuclear aromatic hydrocarbons (PAH's), some of which are carcinogens. It is well established, however, that commercial carbon black which has only trace amounts of adsorbed PAH is neither mutagenic nor carcinogenic. Furthermore, carbon black does not cause heart disease or other major illness in animals, except for symptoms associated with lung congestion at dust levels more than tenfold greater than the OSHA PEL of 3.5 mg/ra3. Epidemiologic studies of workers exposed to carbon black dust in North America and Western Europe show no excess in mortality or morbidity due to cancer, heart disease, or respiratory disease. This is generally supported by more limited studies in the USSR and Eastern Europe, except for evidence of respiratory illness in some cases. Due to the absence of adequate control groups and exposure measurements, it is not known whether this apparent health effect results from unusual conditions of occupational exposure—high levels of carbon black and/or other substances—or is due to environmental factors (e.g., cigarette smoking).

This article addresses the problem of assessing exposures to chemical agents which are regulated with multiple limits such as a permissible exposure limit (PEL) and an action level (AL). If exposures are described adequately by a lognormal distribution, the mean exposure is correlated with the frequency of large excursions above any particular value. This implies that by controlling the mean value below the lower exposure limit, one can constrain the frequency of exposures above the upper limit and vice versa. For example, if the mean exposure is maintained below the AL = 0.5 (PEL), then a maximum of 12 percent of the lognormally-distributed exposures are expected to exceed the PEL regardless of the degree of temporal variability. Furthermore, this property is independent of the averaging time of the measurements, thus samples collected over eight hours or longer can be used to limit the frequency of exposures in excess of a short-term exposure limit (STEL). Several applications regarding pairs o...

To assess quantitatively the association between benzene exposure and leukemia, we examined the mortality rate of a cohort with occupational exposure to benzene. Cumulative exposure for each cohort member was estimated from historical air-sampling data and, when no sampling data existed, from interpolation on the basis of existing data. The overall standardized mortality ratio (a measure of relative risk multiplied by 100) for leukemia was 337 (95 percent confidence interval, 154 to 641), and that for multiple myeloma was 409 (95 percent confidence interval, 110 to 1047). With stratification according to levels of cumulative exposure, the standardized mortality ratios for leukemia increased from 109 to 322, 1186, and 6637 with increases in cumulative benzene exposure from less than 40 parts per million-years (ppm-years), to 40 to 199, 200 to 399, and 400 or more, respectively. A cumulative benzene exposure of 400 ppm-years is equivalent to a mean annual exposure of 10 ppm over a 40-year working lifetime; 10 ppm is the currently enforceable standard in the United States for occupational exposure to benzene. To examine the shape of the exposure-response relation, we performed a conditional logistic-regression analysis, in which 10 controls were matched to each cohort member with leukemia. From this model, it can be calculated that protection from benzene-induced leukemia would increase exponentially with any reduction in the permissible exposure limit.

This discussion will deal primarily with permissible radiation levels in relation to occupational exposure. While such levels are intimately related to those for the general population, this phase of the problem will not be discussed in detail. For the past twenty-five years this country has based its permissible occupational exposure levels on the recommendations of the National Committee on Radiation Protection (NCRP) and the International Commission on Radiological Protection (ICRP). In both cases the exposure levels have been determined primarily by the effect of radiation upon the individual. The current permissible weekly level is based on the premise that a whole-body exposure of 0.3 rem∕week for an indefinite period would not produce any detectable harmful effect. It should be pointed out that at the time these levels were set, in 1948, extensive consideration was given to the effect of radiation on the genetic system and upon the average expected life-span of the occupationally irradiated populat...

A gross anatomy laboratory for medical students was evaluated for formaldehyde levels throughout its eight-week term. Results indicated that exposures for students and instructors were below the 3-ppm permissible exposure limit (assuming a maximum of five hours of daily exposure) established by the Occupational Safety and Health Administration. However, about one third of the eight-hour time-weighted-average exposures were greater than 1 ppm under the same assumptions. Exposure levels for students and instructors did not differ. Exposures tended to decrease over the term unless internal cadaver cavities were being dissected. These exposures are significant in light of the recent implication of formaldehyde as an animal carcinogen and the trend to reduce permissible levels to 1 ppm or lower.

A sampling and analytical method for the measurement of ethylene oxide (EtO) short-term exposure limits (STEL) was validated under both laboratory and field conditions. These studies were designed to examine the method against both the Occupational Safety and Health Administration (OSHA) EtO permissible exposure limit (PEL) method requirements and the National Institute for Occupational Safety and Health (NIOSH) industrial hygiene method validation criteria. The method's pooled accuracy was shown to be within both OSHA requirements and NIOSH guidelines. The EtO was collected on a JXC charcoal tube at a sample flow rate of 100 mL/min for 15 min. The samples were shipped on dry ice and were stored in a freezer until analyzed. The EtO was desorbed by carbon disulfide and the eluent was analyzed by gas chromatography with flame ionization detection (GC-FID). The desorption efficiency of EtO from JXC charcoal tubes was determined to be 84% over the 15-min time-weighted average concentrations: 2.5, 5.0 and 10 ppm EtO. The method limit of detection was determined to be 1.0 ppm. The coefficient of variation of the combined sampling and analytical method was 5.7%. A -7% method bias was calculated. Field validation of the method included data from a portable GC-FID for the determination of method bias. Results of the field validation study over the concentration range of 2.4 ppm to 19.9 ppm generated a field precision of 8.1% with an absolute bias of 3.9%. The method accuracy was determined to be +/- 20%.(ABSTRACT TRUNCATED AT 250 WORDS)

In 1982, White et al published an assessment of quantitative leukemia risk associated with lifetime occupational exposure to benzene. At about the same time, IARC (1982) published estimates of quantitative cancer risk associated with industrial chemicals. Benzene was one of the two chemicals selected by IARC for its risk estimation. This paper presents a summary of these assessments along with new study results demonstrating adverse effects on bone marrow and peripheral blood cells as a result of low-level benzene exposure. Mathematical extrapolations based on epidemiologic studies are consistent with a finding of significant risk of dying from leukemia under the current occupational permissible exposure limit of 10 ppm. Although a significant reduction of risk could be expected to be achieved by reducing exposure to 1 ppm, a significant risk may still remain. The uncertainty of the dose-response projections rests on the underlying estimates of relative risk of death from leukemia, the estimates of benzene exposure (dose), and the appropriateness of the mathematical model. Recent findings in experimental animals demonstrate chromosomal damage to bone marrow cells, significant depression of the bone marrow, and disturbances of immune system function as a result of less than 1 week of exposure to the current permissible benzene exposure limit of 10 ppm. This was the lowest dose tested. These experimental findings provide further evidence of a potentially significant risk of bone marrow proliferative cancer (leukemia) as a result of low-dose benzene exposure.

Nine workers at a 55-gallon drum manufacturing plant had history of exposure to a paint powder that contained trimellitic anhydride (TMA). Environmental monitoring revealed airborne levels of TMA to be over 100 times the OSHA permissible exposure limit of 0.04 mg/m3. The exposed workers were evaluated in a cross-sectional study by questionnaire, physical examination, screening pulmonary function tests, serial peak expiratory flow rates (PEFR), and serum antibody levels. Four workers had symptoms consistent with TMA-induced irritant effects. Three had symptoms and IgG levels consistent with TMA late respiratory systemic syndrome (LRSS). Two of these three had PEFR changes that showed significant drops (greater than 20%) 12-18 hours after the end of a work shift. The material safety data sheet for the paint powder failed to list TMA as an ingredient. Despite the well-described toxic effects of TMA, the present study documents that TMA-related illness may continue to be a problem in situations where workers and management are not properly notified of the potential hazards. The measurement of PEFR may be useful in identifying TMA-exposed workers with LRSS.

Twenty-one subjects exposed to formaldehyde (at levels between 0.12 and 1.6 parts per million [ppm]) in two mobile trailers and the remaining 18 unexposed workers of the same workforce were examined by questionnaire and spirometry. Symptoms of eye and throat irritation and increased headache and fatigue were significantly more common among the exposed group than the comparison group. Irritation of the nose, chest tightness, and shortness of breath were also more common among the exposed. Spirometry revealed no decrease in ventilatory function among the exposed workers. The significant increase in frequency of individuals with symptoms indicated an adverse health effect from exposure to formaldehyde at levels between 0.12 and 1.6 ppm. This may have implications regarding the adequacy of the US permissible exposure limit value and suggests the need for further examination of the health effects of formaldehyde in the nonoccupational environment.

Severe respiratory tract irritation occurred in at least 74 of 100 boilermakers who were exposed to high levels of vanadium pentoxide fume during oil-to-coal conversion of a utility company power plant in a rural area of western Massachusetts. Many were welders working in confined areas with inadequate ventilation. Most frequent symptoms were productive cough, sore throat, dyspnea on exertion, and chest pain or discomfort. The illness was severe enough to cause 70 workers to consult physicians and most of them to lose time from work (median, five days). Wheezing (in 39%) was the most frequent finding on physical examination. Mild hypoxemia was noted in several workers; most (72%) had normal chest x-ray films. Expiratory flow rate over the middle 50% of the forced vital capacity was the pulmonary function test most remarkably affected (median, 57% of predicted for 24 workers tested). The Occupational Safety and Health Administration documented levels of vanadium pentoxide fume at or above the permissible exposure limit in all eight air samples taken from inside the boiler; it cited the company for inadequate mechanical ventilation and an inadequate respiratory protection program for workers. The report of this outbreak may help prevent future problems by drawing attention of physicians, workers, and managers to the potential pulmonary hazards in power plant conversion.

Furfural is a cyclic, unsaturated aldehyde existing as a colorless, oily liquid which readily oxidizes in air. It possesses a characteristic “thick, sweet” odor. This compound is generally produced from various pentosans found in cereal straws and brans. Although there is only one industrial source of furfural in the United States, there is no available information on annual production. This compound finds usage in the formulation of varnishes, insecticides, fungicides, germicides, as a vulcanizing agent in the rubber industry and as a component in various resin systems. The current Permissible Exposure Limit established by OSHA is 5 parts per million.

A comprehensive industrial hygiene survey was conducted at a western copper smelter and arsenic trioxide production facility. The major contaminants reported are arsenic, copper, and lead. The greatest concern noted was for the arsenic measurements found, 69% of which exceeded the 10 micrograms/M3 permissible exposure limit. The company must use a combination of feasible engineering and administrative controls as well as a sophisticated respiratory protection program, however, the efficacy of that program will require continued study and evaluation.

The proposed revision of the US standard for occupational exposure to ethylene oxide has recently been topical and controversial. Most of the recent experimental and epidemiological evidence of health effects, which provoked lowering the permissible exposure limit, appears to be unreliable and insufficient for risk assessment.

The concept of establishing a "threshold limit" for contaminants of industrial air is based on the principles of establishing: (1) quantitative relationships between the magnitude and duration of exposure to an industrial substance and the nature and magnitude of the response of the worker, and (2) a limiting level of exposure to potentially hazardous agents, when there exists no significant threat to health. This paper focuses on the origin of this concept, and traces the history and development of thought concerning the founding principles upon which it is based. The TLVs have undergone a remarkable evolution, from values denoting concentrations of contaminant producing overt signs of acute toxicity, to those concentrations to which nearly all workers may be exposed for their working lifetime without experiencing adverse health effects.

Respirable crystalline silica dust generated during stone crushing operations has been linked to chronic lung disease and increased risk of tuberculosis. In India, most stone crushing mills operate without any dust control or containment systems. This investigation in the Khurda District of Orissa demonstrated a reduction in respirable particulate mass following the application of a fine mist of water. Average respirable quartz and cristobalite levels declined 82% and 69%, respectively, after water spray controls were installed. This finding suggests that relatively inexpensive modifications that are available in the local market can be effective at reducing silica exposures. Although average exposure levels, particularly during the dry season, may exceed the Permissible Exposure Limit for silica, the overall reductions observed were substantial. Widespread adoption of this simple control technology by stone crushers in India could have a positive public health impact.

The results of this study suggest that exposure to styrene below the current Swedish permissible exposure limit of 20 ppm induces neurotoxic effects expressed as an increased number of neuropsychiatric symptoms. Twenty men exposed to styrene at a plastics factory participated. The reference group included 20 non-exposed men matched for age, working schedule, and physical work load. Exposure to styrene during one workday was assessed by personal air monitoring and biological monitoring. To evaluate the physical work load the pulse(heart) rate was measured. One week before the study each man completed a neuropsychiatric symptom questionnaire containing 16 items. Also 17 questions regarding acute symptoms of local irritation and symptoms of the central nervous system were presented after the psychometric tests were performed. The tests were simple reaction time, colour word vigilance, and symbol digit. A follow up with regard to the symptoms among the exposed men was done after their summer vacation, about two to five weeks after their last exposure. The mean eight hour time weighted average (TWA) concentration of styrene in air, measured by passive dosimetry was 8.6 ppm (range 0.04-50.4 ppm). The exposed men had significantly more symptoms than the referents although there were no significant differences for the psychometric tests. At the follow up the exposed men reported fewer symptoms. This study indicates that symptoms are earlier indicators of adverse effects than complex tests and underlines the importance of regular follow up of people exposed to styrene (and probably organic solvents in general).

While exposure to hexavalent chromium (Cr(VI)) has been associated with increased lung cancer risk for more than 50 years, the chemical is not currently regulated by the U.S. Occupational Safety and Health Administration (OSHA) on the basis of its carcinogenicity. The agency was petitioned in 1993 and sued in 1997 and 2002 to lower the workplace Cr(VI) exposure limit, resulting in a court order to issue a final standard by February 2006. Faced with the threat of stronger regulation, the chromium industry initiated an effort to challenge the scientific evidence supporting a more protective standard. This effort included the use of "product defense" consultants to conduct post hoc analyses of a publicly-funded study to challenge results viewed unfavorably by the industry. The industry also commissioned a study of the mortality experience of workers at four low-exposure chromium plants, but did not make the results available to OSHA in a timely manner, despite multiple agency requests for precisely these sorts of data. The commissioned study found a statistically significant elevation in lung cancer risk among Cr(VI)-exposed workers at levels far below the current standard. This finding changed when the multi-plant cohort was divided into two statistically underpowered components and then published separately. The findings of the first paper published have been used by the chromium industry to attempt to slow OSHA's standard setting process. The second paper was withheld from OSHA until it was accepted for publication in a scientific journal, after the rulemaking record had closed. Studies funded by private sponsors that seek to influence public regulatory proceedings should be subject to the same access and reporting provisions as those applied to publicly funded science. Parties in regulatory proceedings should be required to disclose whether the studies were performed by researchers who had the right to present their findings without the sponsor's consent or influence, and to certify that all relevant data have been submitted to the public record, whether published or not.

This paper analyzes current OSHA practice for adjusting the permissible exposure limit (PEL) for inorganic lead to accommodate unusual work schedules. Depending on the work schedule, the PEL adjustment procedure can allow substantially higher exposure or require substantially lower exposure, as compared to the exposure permitted by the lead standard for a normal work schedule. In addition, the procedure allows compliance with the standard by manipulation of the work schedule alone, without reduction in lead exposure. The paper describes how calculating exposure on a weekly basis using the procedure outlined in the OSHA Field Operations Manual would eliminate the seven-fold range of allowed exposure.

The Occupational Safety & Health Administration is reducing the permissible exposure limit for formaldehyde to 1 ppm from 3 ppm, averaged over an eight-hour workday. OSHA estimates that some 2 mill...

In a sweeping move uncharacteristic of the agency, the Occupational Safety & Health Administration is proposing a toughening of its permissible exposure levels (PELs) for 234 chemicals. It sets exposure limits for the first time for another 168 chemicals, reaffirms existing limits for 25 substances, and raises a limit for one chemical, fluorine. OSHA estimates the new limits will reduce work-related illnesses 50,000 cases each year. Total compliance costs are estimated at $928 million annually. The proposal stands in sharp contrast to OSHA's traditionally lenient posture toward regulating exposure to hazardous chemicals. In OSHA's 17 years of existence, the agency has produced comprehensive standards for only 24 substances. As OSHA Administrator John A. Pendergrass pointed out, the substance-by-substance approach obviously could not keep up with the number of chemicals in the market. Thus the current proposal, which he called "a major milestone in the history of workplace protection in this country. . . . ...