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Methods of generating nano-objects with stable concentration – literature review
BEATA KACZOROWSKA s. 6
Nanotechnology is a modern, wide fi eld of science, which combines the achievements of chemistry,engineering, biology, physics and computer science. Unfortunately, nanoparticles, because of their small sizes in a relatively way overcame the barrier of the human systematic compartment and rapidly penetrate the body and settle mainly in lungs.
This paper presents a literature review on methods of generating nano-objects with stable concentrationsused for the validation of measuring devices for testing parameters of nano-objects in real-time. Methods of generating nano-objects using the techniques of nucleation and spark discharge were analyzed during the literature review.
Knowledge of how to generate such particles can be used in predicting exposure to nano-objects in a workplace as well as in designing technological processes in such a way to reduce the risks connected with releasing nanoparticles.
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3,3’-Dimethoxybenzidine Documentation of proposed values of occupational exposure limits (OELs)
ANDRZEJ STAREK s. 15
3,3’-Dimethoxybenzidine (DMOB) is a crystalline substance used to produce azo dyes and also asadherent agent and polyurethane elastomers ingredient. The dye and pigments DMOB-derivative are used to paint leather, paper, plastic and rubber. Occupational exposure to this compound occurs during its synthesis and usage of azo dyes. In Poland, according to the data provided by the Chief Sanitary Inspectorate, the number of employeesexposed to DMOB in 2005-2013 gradually increased and achieved 364 persons in 2013. There is a lack of data on acute poisoning of humans by DMOB. Symptoms of chronic intoxication by this compound may be systemic hypoxiacaused by methemoglobinemia and hematuria. The oral LD50 value in rat indicates that DMOB is a harmful compound. In experimental animals repeatedly treated with this compound the increase in both liver and kidney weights, alterations in thyroid gland, an increase in erythropoiesis in spleen, degeneration and also necrosis of hepatocytes
in central zone of hepatic lobules were observed.
The recommended maximum exposure limit (MAC) for DMOB of 0.2 mg/m3 is based on the risk assessment of tumours appearance in male rats chronically exposed to this compound through the alimentary tract. On the basis of slope factor (SF) value for the dose-response relationship and relevant uncertainty factors the MAC value at risk level of 10-4 was calculated. No STEL and BEI values have been proposed. “Carc 2B” notation (carcinogenic substance) was proposed.
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Hydrazine. Documentation of proposed values of occupational exposure limits (OELs)
MAREK JAKUBOWSKI, MAŁGORZATA KUPCZEWSKA-DOBECKA s. 35
Hydrazine is a liquid used in various industries. In 2011 in Poland, approximately 2000 people were exposed to hydrazine and its salts.
This compound is strongly irritating to the eyes, skin and respiratory system.
Hydrazine has been classified to a carcinogen category 1.B. Carcinogenicity of hydrazine has been proven in animals. The results of exposure were benign and malignant tumors of the nasal cavity, lungs and liver. There is no conclusive evidence of carcinogenicity in humans.
In Poland, TWA of 0.05 mg/m3 and STEL of 0.1 mg/m3 are valid. The ACGIH TLV proposed value of 0.013 mg/m3. The SCOEL did not establish normative values because proper effects to assess toxicity of hydrazine are carcinogenic and genotoxic effects. The assessment of possible effects in humans is not possible because of interspecific differences in the carcinogenic effects on the upper airways. The European Union propose a binding BOELV value of 0.013 mg/m3.
Animal studies suggest that a liver is a critical organ as a result of exposure to hydrazine. The results of studies of chronic inhalation exposure of Syrian hamsters to hydrazine were used to determine the value of MAC-NDS. The critical effects were hepatotoxic: amyloidosis, hemosiderosis and proliferation of bile ducts. The LOAEL value is 0.332 mg/m3.
Derived limit value is 0.014 mg/m3 and the STEL value is 0.042 mg/m3 because of the irritant effects. Labeling as Carc. 1.B (carcinogenic category 1.B), "Skin" and "I"(irritant) was suggested.
After discussion and voting at the 77th meeting of the Interdepartmental Commission for MAC and MAI (January 14, 2015) exposure limit value TWA of 0.013 mg/m3 and STEL value of 0.039 mg/m3 was a possible because of interspecific differences in the carcinogenic effects on the upper airways. The European Union propose a binding BOELV value of 0.013 mg/m3.
Animal studies suggest that a liver is a critical organ as a result of exposure to hydrazine. The results of studies of chronic inhalation exposure of Syrian hamsters to hydrazine were used to determine the value of MAC-NDS. The critical effects were hepatotoxic: amyloidosis, hemosiderosis and proliferation of bile ducts. The LOAEL value is 0.332 mg/m3.
Derived limit value is 0.014 mg/m3 and the STEL value is 0.042 mg/m3 because of the irritant effects. Labeling as Carc. 1.B (carcinogenic category 1.B), "Skin" and "I"(irritant) was suggested.
After discussion and voting at the 77th meeting of the Interdepartmental Commission for MAC and MAI (January 14, 2015) exposure limit value TWA of 0.013 mg/m3 and STEL value of 0.039 mg/m3 was accepted. This values are consistent with binding values adopted by the ACSH.
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Ethyl carbamate. Documentation of proposed values of occupational exposure limits (OELs)
JADWIGA SZYMAŃSKA, ELŻBIETA BRUCHAJZER, BARBARA FRYDRYCH s. 68
Ethyl carbamate (urethane, CAS 51-79-6) is a solid, odorless and soluble in water and organic solvents.
In an environment it occurs as a natural product produced during alcoholic fermentation of foods and beverages containing alcohol. They could be the main source of exposure of the generalpopulation. The technical formulations of
ethyl carbamate, obtained through organic synthesis, achieve a high chemical purity. Ethyl carbamate is mainly used as an intermediate in organic synthesis (including manufacturing amino resin), and its aqueous solutions as solvents for pesticides, fumigants, cosmetics and pharmaceuticals used in veterinary medicine.
In Poland, occupational exposure to ethyl carbamate (inhalation and/or skin contact) occurs in several plants producing and using it, and many people are exposed every year. In humans, no acute poisoning with ethyl carbamate
was noticed. There is no information in theavailable literature about epidemiological dataand chronic toxicity in humans occupationally
exposed.
The LD50 value of ethyl carbamate given intragastrically to rats is 1810 mg/kg of body weight. In acute intoxication in animals, narcosis and sedation
(used in veterinary medicine) and narcoticeffects were observed. Ethyl carbamate did notshow irritation and sensitization for animals.
Subchronic exposure of rats and mice on ethyl carbamate administered in drinking water (with concentrations of 110 — 10.000 ppm, or in doses of 8 — 622 mg/kg/day for rats and 18.3 — 1667 mg/kg/day for mice) resulted in, depending on the sizeof the exposure, immunosuppressive activity. In animals, observed nephropathy and cardiomyopathy were also, and in males also damages to liver were observed. In addition to the immunotoxicity
in mice, proliferation changes in the genital tract and in the lungs were observed.
After 2-year exposure of mice for ethyl carbamate in drinking water (with concentrations of 10 to 90 ppm, corresponding to a dose of 1.17 to
12 mg/kg/day) the toxic effects for liver, heart, lung, and uterus were observed. Ethyl carbamate in concentration in water 30 or 90 ppm (4 or
12 mg/kg /day) caused an increasing number of deaths of animals.
Based on the results of standardized tests, ethylcarbamate is classifi ed as a substance with a weakmutagenic and genotoxic effects.
The results of subchronic and chronic toxicity studies of ethyl carbamate administered in variousways and various species of laboratory animals
show its carcinogenic effect. The compound was found as a cause of cancer of lung, liver, blood vessels and skin, and lymphomas and leukemia.
Ethyl carbamate cause a negative impact on fertility.
It has embryotoxic, fetotoxic and teratogenic effects.
Ethyl carbamate is absorbed into an organism rapidly and completely after exposure in different ways and is immediately subjected to distribution
in a body. Majority of ethyl carbamate (90%) is metabolized to ethanol, ammonia and carbon dioxide, which is excreted in the expired air.
About 5% of ethyl carbamate is transformed by CYP2E1 to the vinyl carbamate and then to vinyl carbamate epoxide which, by binding to DNA
and RNA, is responsible for the genotoxic and carcinogenic effects of the compound. The excretion
of metabolites in the urine and faeces is low and amounts 2 — 8% and 0.3 — 1%, respectively. Ethyl carbamate classifi ed by IARC (2010) as 2.A
group — agents probably carcinogenic to humans.
The European Union classifi ed it as 1.B group — substances that can cause cancer.
The maximum allowable concentration (MAC) for ethyl carbamate was not set in any country.
SCOEL did not established OEL values, since the compound is in Group A carcinogenicity, i.e., genotoxic carcinogens with no establish limit values
based on health effect. Ethyl carbamate causes the cancer in rats and mice in many target organs following administration to a differently ways.
Ethyl carbamate is toxic, mutagenic or clastogenic, especially in the presence of a metabolic activation. Based on this estimation it is proposed to accept
the MAC-TWA value for ethyl carbamate at risk 10-4 or 0.001 mg/m3. There is no reason to determine the value of short-term exposure limit (STEL) and the biological exposure index (BEI).
Additional labeling as „Carc. 1.B”, “Ft — fetotoxicity” and „skin — absorption of substances through the skin may be similarly important, as with inhalation” was proposed.
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Dimethylamine. Determination in workplace air with high-performance liquid chromatography (HPLC )
MARZENA BONCZAROWSKA, SŁAWOMIR BRZEŹNICKI s. 108
Dimethylamine (DMA) is a colorless fl ammable gas with an ammonia- or fi sh-like odor. It is used in manufacturing pesticides, pharmaceuticals,
as an accelerator in vulcanizing rubber, and as a dehairing agent in the tanning industry. It is also widely used in chemical and textile industries.
Occupational exposure to DMA vapours can cause irritation of the respiratory tract or serious injuries to eyes or skin.
The aim of this study was to develop and validate a sensitive method for determining DMA concentrations in workplace air in the range from 1/10
to 2 MAC values (maximum admissible concentration), in accordance with the requirements of standard PN-EN 482.
Studies was performed using high-performance liquid chromatography (HPLC). A Waters Alliance 2695 liquid chromatograph equipped with a quaternary pump, Waters Symmetry C-18 (150 x 2.1 mm; 5 μm) analytical column, spectrophotometric detector (UV-VIS), spectrofl uorimetric
detector (FLD) and autosampler were used for chromatographic separations.
This method is based on the adsorption of DMA on silica gel coated with 2 M/L hydrochloric acid (HCl). The adsorbed compound is eluted with
a mixture of acetonitrile and water and then derivatized with 9-fl uorenylmethyl chloroformate (FMOC-Cl). Extraction effi ciency of DMA from
silica gel coated with HCl was 98,6 %. Samples of DMA on silica gel coated with HCl can be stored in a refrigerator for up to 10 days. Application of
a Waters Symmetry column eluted with mixture of acetonitrile and water (62: 38) made it possible to selectively determine DMA in a mixture of
other amines.
This method is precise and accurate (r = 0.999) within the investigated working range of 0.33 ÷ 13.3 μg/ml (0.6 μg/ml to 24 μg/ml DMA-HCl),
which is equivalent to air concentrations from 0.17 to 6.64 mg/m3 for a 10-L air sample. The limit of quantifi cation (LOQ) for UV-VIS and FLD
detectors was 0.14 and 0.035 μg/ml, respectively. The analytical method described in this paper made it possible to selectively determine DMA
in workplace air at concentrations from 0.17 to 6.64 mg/m3. This method is precise, accurate and it meets the criteria for procedures for measuring
chemical agents listed in EN 482:2006. This method can be used for assessing occupational exposure to DMA and associated risk to workers’ health. The developed method of determining dimethylamine has been recorded as an
analytical procedure (see appendix).
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Peracetic acid. Determination in workplace air
JOANNA KOWALSKA, AGNIESZKA WOŹNICA s. 125
Peracetic acid (PAA) is a colorless liquid. It occurs in a form of a mixture in which it remains in a state of chemical equilibrium with hydrogen peroxide
and acetic acid. PAA is frequently used as a bleach, disinfectant and oxidizing agent.
The aim of this study was to develop and validate a sensitive method for determining PAA concentrations in workplace air in the range from 1/10
to 2 MAC values, in accordance with the requirements of standard PN-EN 482.
The method is based on passing the air with PAA through impinger fi lled with water. PAA was determined indirectly by determining the product of its reaction with methyl-p-tolyl sulfi de (MTS).
Studies were performed using high-performance liquid chromatography (HPLC). An Agilent Technologies (Germany) chromatograph, series 1200,
with a diode-array detector (DAD) was used in the experiment. An Ultra C18 column (250 x 4.6 mm, dp = 5 μm) with a precolumn (10 x 4.0 mm; Restek,
USA) was applied. PAA could be determined in workplace air at the
concentration range from 0.08 to 1.6 mg/m3. The use of ultra C18 column makes it possible to determine PAA.
PAA absorbed in water with methyl-p-tolyl sulphide (MTS) and corresponding sulphoxide ensure the stability of a samplee. The method is precise, accurate and it meets the criteria for procedures for measuring chemical agents listed in
EN 482:2006. This method can be used for assessing occupational exposure to PAA and associated risk to workers’ health. The developed method of determining PAA has been recorded as an analytical procedure (see appendix).
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Thallium and its compounds. Determination in workplace air
JOLANTA SURGIEWICZ s. 143
Peracetic acid (PAA) is a colorless liquid. It occurs in a form of a mixture in which it remains in a state of chemical equilibrium with hydrogen peroxide
and acetic acid. PAA is frequently used as a bleach, disinfectant and oxidizing agent.
The aim of this study was to develop and validate a sensitive method for determining PAA concentrations in workplace air in the range from 1/10
to 2 MAC values, in accordance with the requirements of standard PN-EN 482.
The method is based on passing the air with PAA through impinger fi lled with water. PAA was determined indirectly by determining the product of its reaction with methyl-p-tolyl sulfi de (MTS). Studies were performed using high-performance liquid chromatography (HPLC). An Agilent Technologies
(Germany) chromatograph, series 1200, with a diode-array detector (DAD) was used in the experiment. An Ultra C18 column (250 x 4.6 mm, dp = 5 μm) with a precolumn (10 x 4.0 mm; Restek, USA) was applied.
PAA could be determined in workplace air at the concentration range from 0.08 to 1.6 mg/m3. The use of ultra C18 column makes it possible to determine
PAA.
PAA absorbed in water with methyl-p-tolyl sulphide (MTS) and corresponding sulphoxide ensure the stability of a samplee. The method is precise, accurate and it meets the criteria for procedures for measuring chemical agents listed in
EN 482:2006. This method can be used for assessing occupational exposure to PAA and associated risk to workers’ health. The developed method
of determining PAA has been recorded as an analytical procedure (see appendix).
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