Occupational Exposure Limit Values Research Articles

4,4’- Isopropylidenediphenol – inhalable fraction. Documentation of proposed values of occupational exposure limits (OELs)

4,4’- Isopropylidenediphenol – inhalable fraction. Documentation of proposed values of occupational exposure limits (OELs)

Phenolphthalein – inhalable fraction. Documentation of proposed values of occupational exposure limits (OELs)

Phenolphthalein is a colorless and odorless crystalline solid; in a powdered form white or pale yellow. It is non-volatile, practically insoluble in water, but it dissolves in ethanol. Phenolphthalein is not known to occur as a natural product. The synthetic substance is used as a pH indicator in laboratories, during work on metal surfaces in galvanizing plants as well as for measuring the saturation of concrete with carbon dioxide. Until the end of the 20th century, it was widely used as a component of non-prescription laxatives – in 1999 FDA removed phenolphthalein from the list of substances considered safe. In 2016 in Poland 255 enterprises were reported to work with phenolphthalein (mainly laboratories) and there were 2500 occupationally exposed people. Phenolphthalein used in therapeutic doses was well tolerated. Only a few side effects were reported: abdominal discomfort, nausea, reduced blood pressure and weakness. Chronic use of phenolphthalein resulted in widening of the colon, reduced thickness of the lining of the mucosa, gastric disorders, dehydration and electrolyte imbalance. In a 13-week study in which phenolphthalein was administered to laboratory animals with diets, mice turned out to be a more sensitive species from rats. Changes in testes and epididymides were observed in males and hypoplasia and bone marrow necrosis in males and females. The results of genotoxicity studies indicated that phenolphthalein acts as a promutagen and exerts a clastogenic effect after metabolic activation. Studies on the effect of phenolphthalein on the reproduction of animals indicated its harmful effect on reproductive functions of males. In the EU, phenolphthalein is classified as a category-2 mutagen and category-2 reproductive toxicant (due to its effect on fertility). A small increase in the risk of colorectal cancer and ovarian cancer was observed in case-control studies in patients using phenolphthalein-based laxatives (especially with intensive use of these agents), but the relationship was not statistically significant. In a 2-year NTP carcinogenicity study a significant increase in the number of benign phaeochromocytomas and adenomas of renal tubular epithelium was observed in male rats. There was also a significant increase in histiocytic sarcomas in mice of both sexes and in malignant lymphomas (of all types) and thymic lymphomas and benign ovarian tumors in females. Based on these experiments phenolphthalein has been identified as a substance reasonably anticipated as human carcinogen (NTP R). The experiment on heterozygous p53 (+/-) mice of both sexes confirmed an increase in lymphoma cases. Phenolphthalein is classified by European Union experts as a category-1B of carcinogenic substances, i.e. known or presumed human carcinogens, however the classification is largely based on animal evidence. The European Chemicals Agency (ECHA) identified phenolphthalein as a substance of very high concern (SVHC). Based on the NTP test results, the additional risk of malignant lymphoma at 8.25 mg/m3 occupational exposure to phenolphthalein for 40 years is 10-4. A concentration of 8 mg/m3 was proposed as the MAC-TWA value for phenolphthalein. Since phenolphthalein is a poorly water-soluble solid, only dust exposure of the substance will occur in the work environment, hence the proposed MAC value should concern the inhalable fraction of the substance. It is proposed to label phenolphthalein as "Carc. 1B" indicating that phenolphthalein is a category-1B carcinogen and "Ft" due to reprotoxicity. There are no bases for establishing the short-term exposure limit value (STEL) and the limit value in biological material (BEI).

Phenylhydrazine and its salts – calculated on phenylhydrazine. Documentation of proposed values of occupational exposure limits (OELs)

Phenylhydrazine and its salts – calculated on phenylhydrazine. Documentation of proposed values of occupational exposure limits (OELs)

Buta-1,3-diene. Documentation of proposed values of occupational exposure limits (OELs)

Buta-1,3-diene is a gas used in the production of thermoplastic resins, elastomers and synthetic rubber. Buta-1,3-diene is absorbed mainly in the respiratory tract and then metabolized to monoepoxide – 1,2-epoxybut-3-ene and diepoxide – 1.2:3,4 diepoxybutane, and after their conjugation with glutathione is excreted with urine. According to data from the Central Registry on Exposure to Substances, Mixtures, Agents or Carcinogenic or Mutagenic Technological Processes, in 2015 the number of people exposed to buta-1,3-diene in Poland was 958 and additionally about 200 were exposed to petroleum substances which carcinogenic effect is depending on the buta-1,3-diene. According to data from sanitary-epidemiological stations, in Poland in 2013 and 2016, there were no workers exposed to buta-1,3-diene at levels exceeding maximum allowable concentration (MAC) of 4.4 mg/m3. Buta-1,3-diene in small concentrations is a mild narcotic agent for humans, while for occupationally exposed workers it has irritating properties to the mucous membranes of the eyes and airways. Buta-1,3-diene is a substance with low acute toxicity to animals (LC50 value for rats is 270 000 mg/m3). This substance is mutagenic and genotoxic, it can cause damage to the genetic material of somatic and germ cells. It has been proved that buta-1,3-diene is carcinogenic for B6C3F1 mice and rats. There is also epidemiological evidence that occupational exposure to buta-1,3-diene is associated with the risk of a cancer of a lymphohematopoietic system. According to the IARC classification, buta-1,3-diene is included in group 1, i.e., carcinogenic substances for humans, and according to ACGIH classification to group A2, i.e., substances suspected to be carcinogenic for humans. In Europe, buta-1,3-diene is classified in Cat. 1A. carcinogens and Cat. 1B. mutagenic compounds. Buta-1,3-diene does not cause fertility disturbances, and its teratogenic effects appeared when doses were toxic to mothers only. In Directive 2017/2398 of the European Parliament and of Council (EU) 2017/2398 of 12 December 2017 amending Directive 2004/37/EC on the protection of workers from the risks related to exposure to carcinogens or mutagens at work for buta-1,3-diene, binding occupational exposure limit value (BOELV ) was at the level of 2.2 mg/m3 (Official Journal of the EU L 345 of 27/12/2017, p. 87). The directive will be in force in the EU Member States on January 17, 2020. It was proposed to adopt the value of the maximum allowable concentration (MAC) of the buta-1,3-diene at the level of 2.2 mg/m3 and the following values of the biological exposure indices (BEI):  1.6 mg of 1,2-dihydroxy-4-(N-acetyl-cystein-S-yl)butane/g creatinine in urine measured at the end of working shift  2.1 pmol/g Hb - hemoglobin adducts: mixture of N-[1-(hydroxymethyl)prop-2-enyl]valine and N (2-hydroxybut-3-enyl)valine in blood showing exposure for the last 120 days. This standard is additionally marked Carc. 1A – a substance with proven carcinogenic effect for humans and Muta. 1B – a substance that is considered mutagenic for humans. There is no evidence for establishing STEL value for buta-1,3-diene. The estimated additional risk of leukemia during the 40-year exposure to buta-1,3-diene at a concentration of 2.2 mg/m3 is 8×10-7, it is lower than the risk for the general population in Poland, which is 7.15×10-5.

Buta-1,3-diene. Documentation of proposed values of occupational exposure limits (OELs)

Buta-1,3-diene is a gas used in the production of thermoplastic resins, elastomers and synthetic rubber. Buta-1,3-diene is absorbed mainly in the respiratory tract and then metabolized to monoepoxide – 1,2-epoxybut-3-ene and diepoxide – 1.2:3,4 diepoxybutane, and after their conjugation with glutathione is excreted with urine. According to data from the Central Registry on Exposure to Substances, Mixtures, Agents or Carcinogenic or Mutagenic Technological Processes, in 2015 the number of people exposed to buta-1,3-diene in Poland was 958 and additionally about 200 were exposed to petroleum substances which carcinogenic effect is depending on the buta-1,3-diene. According to data from sanitary-epidemiological stations, in Poland in 2013 and 2016, there were no workers exposed to buta-1,3-diene at levels exceeding maximum allowable concentration (MAC) of 4.4 mg/m3. Buta-1,3-diene in small concentrations is a mild narcotic agent for humans, while for occupationally exposed workers it has irritating properties to the mucous membranes of the eyes and airways. Buta-1,3-diene is a substance with low acute toxicity to animals (LC50 value for rats is 270 000 mg/m3). This substance is mutagenic and genotoxic, it can cause damage to the genetic material of somatic and germ cells. It has been proved that buta-1,3-diene is carcinogenic for B6C3F1 mice and rats. There is also epidemiological evidence that occupational exposure to buta-1,3-diene is associated with the risk of a cancer of a lymphohematopoietic system. According to the IARC classification, buta-1,3-diene is included in group 1, i.e., carcinogenic substances for humans, and according to ACGIH classification to group A2, i.e., substances suspected to be carcinogenic for humans. In Europe, buta-1,3-diene is classified in Cat. 1A. carcinogens and Cat. 1B. mutagenic compounds. Buta-1,3-diene does not cause fertility disturbances, and its teratogenic effects appeared when doses were toxic to mothers only. In Directive 2017/2398 of the European Parliament and of Council (EU) 2017/2398 of 12 December 2017 amending Directive 2004/37/EC on the protection of workers from the risks related to exposure to carcinogens or mutagens at work for buta-1,3-diene, binding occupational exposure limit value (BOELV ) was at the level of 2.2 mg/m3 (Official Journal of the EU L 345 of 27/12/2017, p. 87). The directive will be in force in the EU Member States on January 17, 2020. It was proposed to adopt the value of the maximum allowable concentration (MAC) of the buta-1,3-diene at the level of 2.2 mg/m3 and the following values of the biological exposure indices (BEI): • 1.6 mg/g creatinine of 1,2-dihydroxy-4-(N-acetyl-cystein-S-yl)butane in urine measured at the end of working shift • 2.1 pmol/g Hb - hemoglobin adducts: mixture of N-[1-(hydroxymethyl)prop-2-enyl]valine and N (2-hydroxybut-3-enyl)valine in blood showing exposure for the last 120 days. This standard is additionally marked Carc. 1A – a substance with proven carcinogenic effect for humans and Muta. 1B – a substance that is considered mutagenic for humans. There is no evidence for establishing STEL value for buta-1,3-diene. The estimated additional risk of leukemia during the 40-year exposure to buta-1,3-diene at a concentration of 2.2 mg/m3 is 8×10-7, it is lower than the risk for the general population in Poland, which is 7.15×10-5.

Personal Dust Exposure and Its Determinants among Workers in Primary Coffee Processing in Ethiopia.

BackgroundCoffee processing has been shown to cause high dust exposure among the workers, but there are few studies from primary processing of coffee, and none of them is from Ethiopia. The aim of this study was to assess dust exposure and its determinants among workers in primary coffee processing factories of Ethiopia.MethodsA total of 360 personal ‘total’ dust samples were collected from the breathing zone of workers in 12 primary coffee processing factories in Ethiopia. Dust sampling was performed with 25-mm three piece conductive cassettes with cellulose acetate filters attached to pumps with flow rate of 2 l min−1 for an average sampling duration of 410 min. The dust samples were analysed gravimetrically using a standard microbalance scale. An observational checklist was used to collect information about possible determinants of dust exposure in the work environment. Linear mixed effect regression models were used to identify significant determinants of total dust exposure.ResultsPersonal total dust exposure levels varied between the three main job groups with a geometric mean (GM) of 12.54 mg m−3 for the machine room workers, 12.30 mg m−3 for the transport workers, and 1.08 mg m−3 for hand pickers. In these three groups, 84.6%, 84.1% and 2.6% of the samples exceeded the occupational exposure limit for organic total dust of 5 mg m−3, respectively. The mixed-effects model for the machine room workers explained 21% of the total variance in total dust exposure, and showed that vigorously pouring coffee from a dropping height was associated with an about two times increase in exposure. For the transport workers, the mixed-effects model that included pouring method of coffee beans, number of huller machine in the room, mixing coffee, and feeding hopper explained 32% of total variance in personal total dust exposure.ConclusionAbout 84% of the dust samples among machine room and transport workers in primary coffee processing factories were above the occupational exposure limit value for organic dust. Proper control measures are necessary to reduce the exposure.

Carbon monoxide elimination for health and safety: new powerful silica-based adsorbents applied in continuous breakthrough experiments at elevated laboratory scale

The adsorption of carbon monoxide (CO) is difficult and the degree of elimination requested is very high, due to the high toxicological risk of CO. Nevertheless, only a few studies deal with this topic. The presented investigations are based on powerful functionalized silica adsorbents which deliver very fast separation kinetics in combination with high binding capacities. Even at very low CO concentrations of 0.9 and 85 ppmv, respectively, high adsorption rates for all investigated adsorbents were detected. In order to demonstrate the effectiveness and selectivity of the new adsorbents, breakthrough experiments at elevated laboratory scale (gas flow rate of 300 mL min−1) were executed with a high CO feed gas concentration of 10,000 ppmv. The experimental results prove that 20 g of the new functionalized silica adsorbent HSU 001-075.2 made sure that the “Eight Hours EC Occupational Exposure Limit Value” of 100 ppmv CO in the air was not exceeded for at least 200 s. In that context, a realistic fire scenario with respect to the CO burden of first responders was focused. The protective efficiency of the new adsorbents was exemplary calculated for the new functionalized adsorbent HSU 031-295.1. According to that, an amount of approximately 0.35 kg is able to decrease a CO concentration of 1000 ppmv in the breathing air of one person under high physical strain (assumed air demand 95 L min−1) to a maximum concentration of 83 ppmv for a protection time of 10 min. In case of a collective fire protection shelter occupied by 10 persons under low physical strain (air demand 30 L min−1), an amount of 3.1 kg is sufficient for their protection against CO intoxication over an assumed time interval of 60 min. These results verify the suitability of the upscaled arrangement of the new developed process for worker’s safety installations as well as for protective equipment of emergency services.

Evaluation of risk assessment approaches of occupational chemical exposures based on models in comparison with measurements

Risk assessments of chemicals in work places are needed to protect workers’ health and safety. Several different strategies can be used for conducting risk assessments. The aim of this study was to investigate approaches to risk assessment of chemicals based on exposure assessment models relative to occupational exposure limits values (OELs) and derived no-effect levels (DNELs) and in comparison with measurements relative to OELs. A second aim was to evaluate the modelled recommended outcome and compare it with measurements of exposure. In this study, 29 situations were assessed with ECETOC TRA, Stoffenmanager® 5.1 and ART. Personal exposure measurements were also performed. The percentage of measured exposure exceeding the recommended output was calculated to investigate the level of conservatism. All the modelled exposures were compared with OELs and DNELs where possible, and the GM of the measured exposure was compared with OELs (risk quotas). For ECETOC TRA, 31% of measured exposure exceeded modelled exposure. For Stoffenmanager® it was 17% and for ART and ART B it was 3% and 0% respectively. Hence, according to our data, ECETOC TRA is the least conservative. An investigation of the risk quotas showed that ECETOC TRA had 4 false safe situations, meaning the risk was low when the model was used but was high when measurements were used. This may lead to underestimating risks. All models had an elevated proportion, ECETOC TRA and ART the highest, of false unsafe situations meaning the risk was low when measurements were used but high when models were used.

3,3'-Dimethylbenzidine and its salts – inhalable fraction. Documentation of proposed values of occupational exposure limits (OELs)

3,3'-Dimethylbenzidine (3,3'-DMB, DMB, o-tolidine) is a solid used (as water-soluble dihydrochloride salt (dimethylbenzidine · 2HCl)) in the production of azopigments, polyurethane elastomers and plastics for coating. Small amounts are also used in diagnostic tests in laboratories. Occupational exposure to dimethylbenzydine occurs mainly during the production and use of pigments to dye textiles, plastics, paper and leather. In 2005–2014, dimethylbenzidine was used in Poland in 18–30 workplaces, where 135–280 people each year (mainly women) were exposed. No epidemiological data and information related to toxic effects of DMB in humans was found in the available literature. The LD50 value (median lethal dose) after single intragastric administration of 3,3'-dimethylbenzidine to rats was 404 mg/kg. After repeated exposure of laboratory animals, liver, kidney, thyroid injury and hematological changes were noted. In the Ames tests with metabolic activation, it was found that metabolites of 3,3'-dimethylbenzidine show stronger mutagenic action than the parent compound. 3,3'-DMB induced also chromosome aberrations and exchange of sister chromatids in in vitro tests. Although 3,3'-dimethylbenzidine is a derivative of carcinogenic benzidine, carcinogenic effects on humans have not been proven. However, research provides data about carcinogenic effect of 3,3'-DMB in animals. After subcutaneous administration of 3,3'-dimethylbenzidine and its dihydrochloride salt in drinking water, Zymbal's and mammary glands tumors, and cancers of uterus, skin, liver, hematopoietic system, small and large intestine were observed in rats. IARC classified 3,3'-dimethylbenzidine in the 2B group (a supposed carcinogenic agent for humans), whereas ACGIH – in the A3 group (proved carcinogenic effect on animals and unknown carcinogenic effect for humans). The European Union (according to the CLP classification) has listed 3,3'-DMB in the 1B category with the inscription "H350 – can cause cancer". The permissible concentrations for 3,3'-dimethylbenzidine have been established in some European countries only (Austria, Slovenia and Switzerland) as 0.03 mg/m3. The basis of the proposed maximum concentration value (MAC-TWA) for 3,3'-dimethylbenzidine and its salts was a risk assessment of cancer in male rats chronically exposed to 3,3'-dimethylbenzidine dihydrochloride in drinking water. Taking into account the cancer risk at the level of 10-4, a concentration of 0.03 mg/m3 for the MAC-TWA value was proposed. There are no basis to determine the short-term value (STEL) and biological limit values (BLV). It was also proposed to label the compound with "Carc 1B", which indicates that it is a carcinogen category 1B, and "skin" – the absorption of substances through the skin may be as important as an inhalation route.

Potassium bromate – inhalable fraction. Documentation of proposed values of occupational exposure limits (OELs)

Potassium bromate (V), (KBrO3) exists as white crystals, crystalline powder or granules. It is highly soluble in water, tasteless and odourless. Potassium bromate is a strong oxidizing agent. In the past it has been used as food additive in flour milling, as an ingredient in fish-paste in Japan, in cheese making, in beer malting, as a component of cold hair wave liquid and an oxidizing compound. Moreover, bromate is formed as a by-product of water disinfection by ozonation and is frequently detected in tap and bottled water. In fact bromate is one of the most prevalent disinfection by-product of surface water. Occupational exposure to potassium bromate occurs mainly in production plants during packaging processes. In Poland, about 1 160 persons were exposed to this compound in 2016. Bromate caused many acute poisonings by accidental ingestion, mainly among children, and more often ingested for tentative suicide by young women, especially hairdressers. In the acute phase of poisoning, gastrointestinal disturbances, irreversible hearing loss, and acute renal failure were observed. Acute renal failure was associated with hemolytic uremic syndrome. There are no data on chronic intoxication of humans by potassium bromate and epidemiological studies on this subject. On the basis of the value of median lethal dose (LD50) per os in rat, potassium bromate has been classified as a compound belonging to the category „Toxic”. Major toxic signs and symptoms in animals after a single intragastric administration of potassium bromate were tachypnea, hypothermia, diarrhea, lacrimation, suppression of locomotor movement, ataxic gait, and animals lying in a prone position. At autopsy the major findings were strong hyperemia of glandular stomach mucosa and congestion of lungs. Microscopically, necrosis and degenerative changes of the proximal tubular epithelium and hearing cells of internal ear were found. It was stated that the compound is not irritating, corrosive or sensitizing. In subchronic and chronic exposure of rodents, potassium bromate led to liver and kidney dysfunction and tubular epithelial damage. Potassium bromate had mutagenic and clastogenic effects. It induced point mutations, structural chromosome aberrations, micronuclei in polychromatic erythrocytes in male mice, DNA oxidative damage by modification of deoxyguanosine to 8-hydroxydeoxyguanosine, and DNA double-strand breakage. Potassium bromate induced neoplasms in rodents and exerted promotion effect in comparison with well-known carcinogens. Besides from preneoplastic changes, expressed by high incidences of renal cell tumors and dysplastic foci, bromate induced solid neoplasms, such as adenomas and adenocarcinomas in a rat kidney and thyroid, and mesotheliomas of peritoneum and tunica vaginalis testis. The European Union classified potassium bromate as a substance that can cause cancer (Group 1.B), whereas IARC classified it as a presumably carcinogenic agent for human (Group 2.B). In principle, effects of bromate on reproduction and ontogenetic development of offspring were not observed. Animal studies suggest that a kidney is a critical organ in the exposure to potassium bromate. The results of subchronic exposure of male rats to potassium bromate administered with drinking water were used to calculate the value of MAC-NDS. The critical effects in kidney were: an increase of organ weight and dose-dependent histopathological alterations defined as epithelium urinary tract hypertrophy. The NOAEL value is 1.5 mg/kg b.w./day. For the calculation of the maximum allowable concentration (MAC) value, 5 uncertainty factors with total value of 24 were used. Based on this estimation it is proposed to accept the MAC-TWA value for potassium bromate at 0.44 mg/m3. The risks of kidney and thyroid cancer in condition of occupational exposure are 2.2 · 10-3 and 0.6 · 10-3, respectively. There is no reason to determine the value of short-term exposure limit (STEL) and the biological exposure index (BEI). „Carc.1.B” notation (carcinogenic substance) was proposed

Adapting national legislation to Directive 2017/164/EU and to Directive 2017/2398/EU amending Directive 2004/37/EC

This article discusses the transposition process of Directive 2017/164/EU of January 31, 2017, establishing the fourth list of indicative occupational exposure limit values into national law, and the Directive 2017/2398/UE of December 12, 2017 amending Directive 2004/37/EC on the protection of workers from the risks related to exposure to carcinogens or mutagens at work.

Quinoline. Documentation of proposed values of occupational exposure limits (OELs)

Quinoline is a colorless hygroscopic liquid with a pungent odor. It darkens with age. It is soluble in alcohol, ether, benzene and carbon disulfide, and is slightly soluble in water. It is used as a solvent and a decarboxylation reagent, and as a raw material in manufacturing dyes, antiseptics, fungicides, niacins and pharmaceuticals. The occupational exposure to quinoline applies to a person involved in the production of the substance or using products manufactured from this substance. The primary routes of potential human exposure to quinoline are ingestion, inhalation, and dermal contact. The most common symptoms of poisoning include eye and skin irritation, damage to the cornea, the retina or optic nerve, headaches and dizziness. Quinoline produced mutations in bacteria in the presence of metabolic activation, unscheduled DNA synthesis in rat hepatocytes, and DNA adducts. Studies of carcinogenicity in animals indicated that administration of quinoline (in feed) increased significantly the incidence of vascular tumors (hemangiomas or hemangiosarcomas) of the liver. Quinoline is classifield as mutagenic category 2 (substance, which is consider as mutagenic to humans) and to category 1B of carcinogenic substances (potent carcinogen to humans – may cause cancer). According to the above data, the MAC value for quinoline was established at 0.6 mg/m3. MAC- -STEL value was not established. The substance was labeled with “sk” (absorption through the skin can be similarly important as inhalation) and “I” – irritant substance.

Workplace Respiratory Protection Factors during Asbestos Removal Operations.

Numerous changes have been made to the French labour regulations in recent years relating to the prevention of risks of exposure to asbestos fibres for operators removing asbestos-containing materials. These changes refer to the method used to count fibres, the collective and personal protective devices to be used on these worksites, and the occupational exposure limit value, which was reduced to 10 f.L-1 on 2 July 2015. In this context, this study assessed the level of respiratory protection afforded by supplied-air respirators and powered air-purifying respirators by monitoring exposure for several operators on nine worksites. The levels of dustiness measured in personal samples taken outside masks showed significant evidence of potential exposure during removal of asbestos-containing plaster or sprayed asbestos, and when using abrasive blasting to treat asbestos-containing materials. For these tasks outside concentration regularly exceeds 25000 f.L-1. Measurements inside masks were generally low, under 10 f.L-1, except in some situations involving the removal of asbestos-containing plaster. This partial penetration of fibres inside masks could be due to the high loading linked to this material. The distributions of Workplace Protection Factors obtained for the two types of respiratory protective devices studied were broad, and the fifth percentile values equal to 236 and 104, respectively, for supplied-air respirators and powered air-purifying respirators. This work highlights once again the need to prioritize collective protection when seeking to prevent asbestos-related risks.

The activity of the Interdepartmental Commission for Maximum Admissible Concentrations and Intensities for Agents Harmful to Health in the Working Environment in 2017 and the work plan in 2018

In 2017, the Commission met at three sessions, in which 16 documentations for recommended exposure limits of chemical substances were discussed. Moreover, the Commission discussed: − the positions of the Interdepartmental Commission for MAC and MAI regarding: smog, limit value of nitric oxide in the underground mining and tunnels sector and binding value for 1,2-dichloroethane − introduction of the "skin" notation (substances absorption through the skin may be important as in the case of inhalation) for chemical substances included in the regulation of the Minister of Labour and Social Policy of 6 June 2014. The Commission suggested to the Minister of Family, Labour and Social Policy the following changes in the list of MAC values: − adding five new chemical substances to the list of MAC values: qinoline (CAS: 91-22-5, Carc. 1B, skin), cisplatin (CAS: 15663-27-1, Carc. 1B, skin), N-hydroxyurea (CAS: 127-07-1, Carc. 1B), potassium bromate (CAS: 7758-01-2, Carc. 1B, skin) oraz 3,3’-dimethylbenzidene (CAS: 119-903-7) and salts: 3,3’ dimethylbenzidene dihydrochloride (CAS: 612-82-2, Carc. 1B) − changing MAC values for 10 chemicals: bis-phenol A (CAS: 80-05-7), acrylic acid (CAS: 79-10-7, skin), nitrogen oxide (CAS: 10102-43-9 ), dichloromethane (CAS: 75-09-2, skin), 1,1-dichloroethylene (CAS: 75-35-4), hydrogenated terphenyls (CAS: 61788-32-7), 2-nitropropane (CAS: 79-46-9, skin), 1,2-epoxypropane (CAS: 75-56-9), 1,2-dichloroethane (CAS: 107-06-2, skin), phenylhydrazine (CAS: 100-63-0, skin) as phenylhydrazine) and its salts: phenylhydrazine hydrochloride (CAS: 59-88-1; 27140-08-5, skin), phenylhydrazine sulphate (CAS: 52033-74-6, skin) − adding to Annex 1 the "skin" notation (substances absorption through the skin may be important as in the case of inhalation) for chemical substances included in the regulation of the Minister of Labour and Social Policy (Journal of Laws of 2014, item 817 with amended). The Interdepartmental Commission for MAC and MAI adopted the MAC value for inhalable fraction of urea at the level of 10 mg/m3 as the value recommended for manufacturers and plants. The documentation of the proposed occupational exposure limit values for urea with the recommended value of 10 mg/m3 and with the method of determining it concentrations in the working environment will be published in "Principles and Methods of Assessing the Working Environment". Four issues of the "Principles and Methods of Assessing the Working Environment " were published in 2017. The following were published: 12 documentation of occupational exposure limit, 12 methods of determining chemical concentrations in the working environment, two articles, a procedure for measuring electromagnetic field, a report on the activities of the Interdepartmental Commission for MACs and MAIs in 2017 and indexes of documentations, methods and articles published between 2000–2017. Three sessions of the Commission are planned for 2018. MAC values for 15 chemicals substances will be discussed at those meetings. The Commission and the Group of Experts will continue working on adapting the Polish list of maximum admissible concentrations to proposals for binding values for carcinogenic or mutagenic substances, proposed concentration limit values developed by the Committee for Risk Assessment (RAC) and on work being done at SCOEL.

Quantitative assessment of occupational exposure to total indium dust in Japanese indium plants.

This study quantitatively assessed personal exposure of 86 workers to indium compounds as total dust at 11 Japanese indium plants. The personal exposures to indium concentrations in the breathing zone during an 8 h work-shift were determined by ICP-MS. The arithmetic mean indium concentration of all the workers was 0.098 mg Indium (In)/m3, with individual values ranging from 0.0001 to 1.421 mg In/m3. There were 11 workers whose exposure to indium concentrations exceeded the American Conference of Governmental Industrial Hygienists’ Threshold Limit Value-Time Weighted Average (TLV-TWA) of 0.1 mg In/m3. Based on the condition TLV-TWA<X95 (upper 95th percentile of log-normal distribution), five indium plants were judged as “control measures required”, while 3 other plants were evaluated as “control measures not required”. Five workers belonging to the worst group were exposed to far higher indium concentrations than the TLV-TWA. Another group of 5 workers belonging to the best group was exposed to far lower indium concentrations than the TLV-TWA, and this was attributed to the stringent engineering control measures used at their workplaces. The quantitative assessment of occupational exposure to indium dust was influenced by different occupational exposure limit values without carcinogenicity and particle size-selectivity of indium particulates or “total” dust.

Do regulations protect workers from occupational exposures to carcinogenic, mutagenic and reprotoxic (CMR) agents in France?

ObjectiveThis article explores the impact of regulations on the implementation of collective protections in France to occupational exposure to carcinogenic, mutagenic and reprotoxic (CMR) agents.MethodsIndividual data from the French national...

Urea – inhalable fraction. Documentation of proposed values of occupational exposure limits (OELs)

Urea is a non-flammable, colorless or white crystalline solid. It has a faint aroma of ammonia and a cooling, saline taste. It is hygroscopic, very well soluble in water. During long-term storage and in aqueous solutions urea partly decomposes with the release of ammonia and carbon dioxide. Urea is used as a: component of fertilizer and animal feed; raw material for production of plastics, flame-proofing agents, adhesives, medicines, cosmetics and household products; reductant in selective catalytic reduction (SCR) systems used to reduce NOx emissions from stationary and mobile sources; deicing compound on roads, railroad tracks and airport runways; in the food industry as an additive for bakery products, alcoholic beverages and gelatine-based products and as a reagent in laboratories. In 2012, world production of urea was estimated to be around 184 million tonnes and is projected to increase further. In the European Chemicals Agency, urea was registered by 5 companies from Poland. The number of workers exposed to urea in 2 of these plants is a total of 201 people. Urea is an endogenous product, formed in the liver in the urea cycle from ammonia formed by the catabolism of amino acids and proteins, is then excreted by the kidneys. An adult man excretes about 20 ÷ 35 g of urea in the urine during the day. Most of the information on the effects of urea in humans comes from patients with renal insufficiency who have elevated urea levels. Adverse effects of urea include: headache, nausea, vomiting, syncope, confusion, electrolyte abnormalities in the blood. Urea has a slight irritating effect on the eyes and does not irritate the skin. At concentrations above 10% urea has a keratolytic effect - it facilitates peeling and increases the permeability of the stratum corneum, thereby increasing the therapeutic activity of many topical medications. Based on animal studies urea has low acute and chronic toxicity and no carcinogenic or reproductive toxicity. Urea does not meet the classification criteria as a CLP hazardous substance. Due to very low vapor pressure, exposure is possible only to urea dust. Therefore, in order to protect workers from the nuisance of particulate matter (dust) of urea, the MAC (TWA) value of 10 mg/m3 was recommended as for other dusts not classified for toxicity but posing a hazard for visibility reasons. There is no basis for determining the short-term exposure limit value (STEL) and the biological exposure index value (BEI).

Flour dust – aspiration fraction Documentation of proposed values of occupational exposure limits (OELs

The term "flour dust" refers to particles derived from finely ground cereal grains and "non-cereal" grains. Flour flour usually also contains ingredients that play an important role in improving dough quality, such as enzymes, additives such as baker's yeast, flavors, spices and chemical ingredients such as preservatives. Flour is one of the basic raw materials used in the food industry and in the production of animal feed. Taking into account the nature of the production activities in mentioned industries, the highest occupational exposure to flour dust is usually observed in bakeries and grain mills. Significant exposure to flour dust is also found in factories of pasta, pizzeria and pastry, restaurant kitchens, malt factories, animal feed factories and agriculture. The main route of exposure to flour dust in occupational conditions is respiratory and skin. The main effect of repeated or long-lasting human exposure to flour dust is irritation and allergy. Epidemiological reports have shown that asthma, conjunctivitis, rhinitis and skin reactions are the main adverse health effects of flour dust exposure. Currently in Poland for flour dust the maximum admissible value (MAC, NDS) is the same as for organic dust (plant and animal origin). The MAC values are: for inhalable fraction 2 mg/m3 and for respirable fraction 1 mg/m3 when dust contains 10% or more crystalline silica and when dust contains less than 10% of crystalline silica, 4 mg/m3 for inhalable fraction and 2 mg/m3 for respirable fraction. The need to prepare documentation for flour dust resulted from the fact that existing documentation and MAC values mainly concern the effects of farmers' exposure to organic dust of plant and animal origin. It did not refer to flour dust for which the sensitization effect is critical. The basic mechanism of action of the flour dust on the body is the reaction of hypersensitivity with stimulation antibodies type E (IgE) developing shortly after exposure to the antigen. The value of hygienic norms for flour dust in Poland has not been established, yet. There is no data regarding animal experiments and in vitro studies with flour dust. On the basis of epidemiological studies, the risk of nasal symptoms has been found to increase with dust concentrations of 1 mg/m3 and the risk of asthma at concentrations above 3 mg/m3. The SCOEL assumes that exposure to the inhalable fraction of flour at a concentration of ≤ 1 mg/m3 protects most exposed workers from nasal mucositis and that the predicted symptoms, if present, are mild. However, the concentration of flour dust &lt;1 mg/m3 may cause symptoms in already sensitized workers. The results of the study show that the full protection against allergens present in the flour dust in the air at low concentrations is difficult to achieve. At the same time, ACGIH's recommended TLV value for the inhalable flour dust fraction at 0.5 mg/m3 (8-h TWA). The "dose-response" results suggest that the symptoms of exposure to flour, especially from the lower respiratory tract, asthma, as well as the risk of sensitization, are rare in the inhalable fraction concentration in the range 0.5  1 mg/m3. Considering the above, the Interdepartmental Commission for MAC and MAI at the 84th meeting of 4.11.2016 adopted the TLV value for the inhalable fraction of flour dust at the level of 2 mg/m3, that is, at the level of the current MAC value for inhalable fraction of dust containing &gt; 10% of the crystalline silica. No grounds for determining the short-term limit MAC(STEL) and the limit value in biological material. The standard is marked with "A" (sensitizing substance).

Wood dust – aspiration fraction Documentation of proposed values of occupational exposure limits (OELs)

Wood dust – aspiration fraction Documentation of proposed values of occupational exposure limits (OELs)

Peak exposures to main components of ash and gaseous diesel exhausts in closed and open ash loading stations at biomass-fuelled power plants

Fly and bottom ashes are collected at power plants to reduce the environmental effects of energy production. However, handling the ashes causes health problems for operators, maintenance workers and truck drivers at the power plants. Hence, we evaluated ash loaders’ peak inhalation exposures to the chemical components of ash and diesel exhausts in open and closed ash loading stations at biomass-fuelled combined heat and power plants. We also carried out chemical and morphological analyses of the ashes to evaluate their health hazard potential in order to find practical technical measures to reduce workers’ exposure. On the basis of X-ray diffraction analyses, the main respirable crystalline ash compounds were SiO2, CaSO4, CaO, Ca2Al2SiO7, NaCl and Ca3Al2O6 in the fly ashes and SiO2, KAlSi3O8, NaAlSi3O8 and Ca2Al2SiO7 in the bottom ashes. The short-term exposure levels of respirable crystalline silica, inhalable inorganic dust, Cr, Mn, Ni and nitric oxide exceeded their Finnish eight hours occupational exposure limit values in the closed ash loading station. According to our observations, more attention should be paid to the ash-moistening process, the use of tank trucks instead of open cassette flatbed trucks, and the sealing of the loading line from the silo to the truck which would prevent spreading the ash into the air. The idling time of diesel trucks should also be limited, and ash loading stations should be equipped with exhaust gas ventilators. If working conditions make it impossible to keep to the OEL values, workers must use respirators and protect their eyes and skin.