Introducing more nanotechnological products into the market requires assessing hazards and risks to human and environment. Registrants, according to the criteria of REACH regulation (Appendix XI), may perform a chemical safety assessment of chemicals with  alternative  methods:  weight of evidence, grouping of substanc-es and read-across approach.
This article presents the selected approaches to grouping strategy of nanomaterials for human health risk and occupational safety assessment.

This article presents rules for determining the occupational limit values (OELs) and intensities of agents harmful to health occurring in the workplace as the basic criteria for providing safe and healthy working conditions in Poland and in the European Union. The role of the Interdepartmental Commission for Maximum Admissible Concentrations and Intensities for Agents Harmful to Health in the Working Environment in this process is also presented in the article. Attention was drawn to links between legal provisions concerning occupational health and safety, and regulations on chemicals (REACH, CLP), which together provide necessary data and tools to employers and the Member States allowing safe work with chemicals and taking appropriate action and risk management measures.

1,2-Dimethoxyethane (EGDMA, ethylene glycol dimethyl ether, monoglym) belongs to the group of alkyl ether solvents. Under normal conditions, it is a colorless, volatile liquid with a faint odor of ether and is very soluble in water.
Poland, Belgium, the Netherlands and Germany has submitted a proposal to the European Chemical Agency on recognizing 1,2-dimethoxyethane as a substance of very high concern because of its harmful effects on reproduction.
There are no data on the acute and chronic toxicity of 1,2-dimethoxyethane at humans in the available literature. A report from the US Department of Transportation describes that the inhalation of vapors of 1,2-dimethoxyethane may cause dizziness, breathing difficulties and in the case of ingestion may cause nausea, vomiting, loss of consciousness (concentrations and doses of a compound not specified).
On the basis of chemical structure of 1,2-dimethoxyethane and its metabolism it can be assumed that this substance can be harmful to hematopoietic system, but there are no data on the effect in humans. Based on epidemiological studies on overall exposure to glycol alkyl ethers it can be noted that the effects observed in humans after the exposure to ethylene glycol alkyl ethers were related to adverse effects on hematological parameters, fertility and fetal development.
1,2-Dimethoxyethane metabolizes mainly to 2-methoxyethanol, next by the enzymatic oxidation to 2-methoxyacetic acid (MAA). 2-Methoxyethanol is a substance which can cause hemolytic anemia and can be harmful to reproduction and development of human fetuses.
The LD50 value after oral administration of 1,2-dimethoxyethane is 2525–4000 mg/kg bw, LC50 value is between 20 mg/l and 63 mg/l, while the LD50 value after dermal administration is in the range of 1000–2000 mg/kg bw.
Data on mutagenicity of ether are inconclusive.
In Chinese hamster ovary cells in vitro, 1,2-dimethoxyethane induced sister chromatid exchange. No data were found on the carcinogenicity of ether or its metabolite 2-methoxyethanol.
On the basis of the analysis of experimental results on laboratory animals it can be concluded that the critical effect of 1,2-dimethoxyethane influences reproduction and development of offsprings. Histopathological changes in seminiferous epithelium and spermatogenesis disorders, aspermia and oligospermia were observed in rats and rabbits exposed by inhalation to 1,2-
dimethoxyethane. Exposing female rats, rabbits and mice to 1,2-dimethoxyethane during organogenesis caused a toxic effect on an embryo (mortality), a reduction in body weight in fetuses, a delay in ossification and growth, an increase of malformations and cardiovascular changes.
In Poland the MAC value of 1,2-dimethoxyethane is not established. From the European Union countries, Latvia established the OEL at
10 mg/m³. In Canada, the tolerable exposure level is 18 mg/m³. The Ferro Corporation is the largest producer of glycol ethers and it recommends the tolerable occupational exposure to glycol ethers at 18.7 mg/m³ (5 ppm calculated as EGDMA) (TWA) and the short-term value (STEL) of 93.5 mg/m³ (25 ppm as EGDMA). For women in the reproductive age, the Ferro Corporation recommends values for the glycol ethers as TWA - 3.74 mg/m³ (1 ppm as EGD-MA) and STEL – 18.7 mg/m³ (5 ppm calculated as EGDMA).
The NOAEC value of 187 mg/m³ determined for rabbits on the basis of changes in the epithelium of the seminiferous tubules (2-week inhalation exposure, OECD 412) was used To calculate MAC values. After applying uncertainty factors, the proposed limit value for 1,2-dimethoxyethane is 10 mg/m³. STEL value was not established. The substance was labeled with "Ft" (a substance toxic to a fetus) and "skin" (absorption of substances through the skin can be similarly important as inhalation).
It should be emphasized that women in the reproductive age should not be employed at workstations where 1,2-dimethoxyethane is used. This contraindication should be included in the regulation of the minister of health on conducting medical tests of employees, scope of preventive health care for employees and medical certificates issued for purposes provided in the Labour Code.

Hexachlorobenzene is a solid substance, insol-uble in water, highly lipophilic with high melting and boiling point and high vapor density. The compound was used in war, electrotechnical, and chemical industries. Nowadays hexa-chlorobenzene is used for laboratory purposes. Except for destination synthesis this compound originates as a byproduct during synthesis of chloroorganic solvents.
In Poland, the exposure to hexachlorobenzene is increasing despite interdiction to its application. In 2005 in Poland, 28 people were exposed to hexachlorobenzene, whereas in 2014 exposed were 167 (men and women). According to Stockholm convention (2001) on persistent organic pollutions (POPs) there is prohibition of production, introduction to trade turnover and usage of hexachlorobenzene.
There is no information about symptoms of acute poisoning by hexachlorobenzene in humans. Chronic intoxications by this compound were caused by uptake it with food, which happened in Turkey towards the end of 50s of last century. These poisonings had epidemic character. The chemical induced in humans, e.g., porphyria cutanea tarda, skin hyperpigmentation and hirsutism, neurological and orthopedic disorders.
The median lethal dose and concentration values in animals indicate that hexachlorobenzene is outside of the classification of chemicals based on an acute toxicity. In experimental animals repeatedly exposed to this chemical, porphyrinogenic, hepatotoxic, thyreotoxic, and ototoxic effects were observed. Hexachlorobenzene as a weak ligand of AhR receptors shows dioxinelike activity. It causes functional disturbances in thyroid gland, ovaries, adrenal gland and leads to reduction of thyroid hormone concentrations, estrogens, glycocorticoids and their receptors.
Hexachlorobenzene is not mutagenic and genotoxic in vitro and in vivo. The epidemiologic examinations did not proved carcinogenic effects of hexachlorobenzene in humans, however, numerous experimental studies noted its carcinogenic, promoting and cocarcinogenic activities. International and national institutions classified hexachlorobenzene to a carcinogen category
2.B (IARC), 1.B (EU, Poland) and to A.3 group (ACGIH).
SCOEL did not established OEL value for hexachlorobenzene, since the compound has cumulative effect. Admissible concentration value in biological material (BLV) of 150 µg/l of serum or plasma and labeling „skin” because the compound is resorbed through the skin was recommended for assessing the exposure to hexachlorobenzene. Hexachlorobenzene is included in the register of the substances for which binding BOELV values should be established. Because of the prohibition (Stockholm convention) and cumulative effect of hexachlorobenzene BOELV value was not established.
Hexachlorobenzene demonstrates reproductive and developmental toxicities. In females of different species, gonadotoxic effects were seen as result of hormonal disturbances, ovarian and egg cells injury which led to ovulation and fertilization impairment.  
The results of study on gonadotoxic effect of hexachlorobenzene in the female cymonolgus monkey exposed per os for 13 weeks were basis for calculating MAC value. The NOAEL value at level of 0.01 mg/kg b.w./day and joind uncertainty factor value of 24 were used to calculate MAC value at level of 0.003 mg/m3. It was recommended to label the substance with “Skin”.
No STEL value has been recommended. In agreement with recommendation of SCOEL, the BLV value at level of 150 µg/l of serum or plasma has been proposed.

Propane-1,2-diol (propylene glycol) is a colorless, strongly hygroscopic liquid used to produce antifreezes, polyester resins and detergents. It is used in the plastics industry as a hygroscopic agent, in textile products and in manufacturing cigarettes (for adjusting moistness of tobacco) and as the major component of the liquid used in electronic cigarettes. In the industry, it is used to produce electrical insulating varnishes, brake fluids, auxiliary materials for foundry, resins and adhesives. In the space technologies, propane-1,2-diol is used as a coolant or coolant component. Propylene glycol is also used in the cosmetic industry (as a component of creams, an additive to toothpastes and mouth rinses, the main ingredient in deodorant stick), medicine, pharmacy, food and in cleaning products.
Nowadays, propylene glycol is not produced in Poland, however, it is produced by dozens of European companies, including German, Belgian, Dutch, British, Irish, Finnish and Spanish. Due to the wide use of propylene glycol in many industries in the production of various products, including those manufactured in Poland, the number of people exposed to it in the workplace can be significant. In Poland, normative hygienic values for propylene glycol have not been established so far.
Propylene glycol is not classified as dangerous substance according to the criteria of Regulation (EC) No 1272/2008 (CLP).
In literature, there are no data on cases of acute poisoning with propylene glycol in working conditions. Clinical observations of people treated with propylene glycol as a solvent for drugs show a weak narcotic effect, mild irritation to the skin and conjunctiva of the eye especially during prolonged exposure and sensitization especially in sensitive individuals.
Animal studies have shown mild irritation under repeated exposure. The use of different techniques of sensitization with propylene glycol of guinea pigs did not cause sensitization.
The results obtained from animal studies on chronic toxicity of food and inhalation of propylene glycol show low-toxicity of this compound. Propylene glycol did not cause any harmful consequences in the described experimental conditions with the exception of changes in the image of peripheral blood. After administration of high doses/concentrations of glycol in animals, signs of liver damage and changes in the image of the peripheral blood but without evidence of damage to the bone marrow and spleen were observed.
There was no mutagenic activity in propylene glycol in tested strains of Salmonella Typhimurium and studies on mammalian cells.
The experimental results indicate that propylene glycol does not display fetotoxicity and does not affect the reproduction when concentrations are nontoxic for a mother. The literature did not provide convincing evidence that propylene glycol can cause teratogenic effects in the offspring of exposed animals.
There was no increase in the number of cancer in cases of mice which had propylene glycol applied to the skin for 120 weeks and rats which received propylene glycol in food in chronic conditions.
A systemic action was considered in determining the normative hygiene of propylene glycol. The value of the maximum permissible concentration of propylene glycol were calculated on the basis of data from tests on rhesus monkeys (Macaca mulatta) and rats which were exposed by inhalation to the vapor of this compound in concentrations from 10 to 348 mg/m³ (monkeys) and from 171 to 348 mg/m³ (rat) for 13–18 months. Based on the experimental NOAEC value (no observed adverse effect concentration) of propylene glycol for both species, limit value for inhalable fraction and vapor of 100 mg /m³ was proposed. The proposed value of the normative hygiene should protect workers from the irritation of propylene glycol and from possible systemic action. There is no reason to label normative as "skin" (the absorption of substances through the skin can be just as important as the inhalation).

Lithium hydride (CAS 7580-67-8) at room temperature is a solid, odorless substance, which reacts violently with water and forms lithium hydroxide. Lithium hydride is an inorganic compound created during chemical synthesis. Lithium hydride is used mainly as an intermediate in organic synthesis, the source of hydrogen and a desiccant. In Poland, the existing norm for lithium hydride in workplace air is MAC-TWA (NDS) – 0.025 mg/m³ (documentation from 1994). Short-term exposure limit (STEL, NDSCh) has not been established.
According to GUS, in 2007, 2010 and 2013 there were no cases of exceeded norms for lithium hydride. SCOEL proposed for inhalable fraction of lithium hydride only short-term exposure limit (STEL 15 min) of 0.02 mg/m³. The basis of this value was no airway irritation when exposed to lithium aluminum hydride at a concentration exceeding 0.025 mg/m³. The value of an 8-hour (OEL) has not been established. The documentation and the recommendation from SCOEL were consulted in 2007. Interdepartmental Commission for MAC and MAI reported the remark to the proposals SCOEL on determining only the short-term exposure limit of the lithium hydride (NC/NDS/18/1907/2008) without setting values for 8-hour exposure. In conclusion, SCOEL stated that lithium hydride has no systemic action and is only irritant, so determined only short-term exposure limit. The Commission's comments were as follows: "The basis of the value STEL proposed in the SCOEL are unpublished results obtained from the studies of workers occupationally exposed to the compound, with not given them the relevant data (number of workers exposed, exposure time). Lithium hydride may be irritating an even corrosive to the mucous membranes of the eyes and respiratory tract and skin. These results from the reaction of an alkali compound, but also the lithium ion has an adverse effect on the nervous system. We therefore believe that there is no basis to determine only the STEL for lithium hydride". In response to the notice, SCOEL reported that therapeutic concentrations of lithium in the blood plasma is far above the value that can be achieved by a professional exposure to lithium aluminum hydride. Inhalation the lithium at a concentration of 0.1 mg/m³ for 8-hour, which at this concentration is strongly irritant, corresponds with the calculated daily dose of 10 mg of lithium (assuming 10 m³ of air inhaled and absorption of 100%). This dose is substantially lower than the dose of lithium estimated during ingestion of food and water and much lower than the daily dose of 167 mg lithium Li/day (specified in Sweden for the treatment of affective disorders). Without data on concentration-effect relationships of long-term exposure, OEL values for lithium hydride has not been established. Due to its irritating property short-term exposure limit (STEL) was proposed. Value STEL of 0.02 mg/m3 for lithium hydride without OEL values for an 8-hour exposure was proposed in a draft directive establishing 4th list of indicative occupational exposure limit values. Therefore, the Group of Experts on Chemical Agents prepared new do-cumentation for the compound. In the available literature, lithium hydride is described as a strongly irritant substance. A high chemical reactivity, especially in a humid environment, causes a risk of irritation and/or corrosion of tissues. Lithium hydride is a potential health risk with acute effects. The consequence of food poisoning can be permanent damage to the cornea, narrowed esophagus and pulmonary edema. Lithium hydride is not mutagenic and carcinogenic. The basis for the proposed MAC values are irritating properties of lithium aluminum hydride in people occupationally exposed to this compound. It is therefore proposed for lithium hydride exposure limit value of 0.01 mg/m³ as TWA-MAC and of 0.02 mg/m³ as short-term exposure limit (STEL). There is no basis to determine the biological exposure index (BEI). Due to strong corrosive effects of lithium hydride it was recommended to label the compound with the letter "C" – a corrosive substance.

Lead is a soft, flexible and grey metal. In industry, it is used as an ingredient of many alloys, jacketing cables, screens protecting against ionizing radiation and battery plates. Lead and its compounds are highly toxic. Lead can cause damage to the nervous, hematopoietic and circulatory systems, and kidneys. It accumulates in bones. It can cause harm to an unborn child and is reprotoxic. The exposure limit values for lead and its inorganic compounds in the working environment, based on Pb for inhalable fraction, are NDS 0.05 mg/m³.
The aim of this study was to develop a method for determining concentrations of lead and its inorganic compounds (in inhalable fraction) in workplace air in the range from 1/10 to 2 NDS values in accordance with the requirements of Standard No. EN 482.
This method involves collecting lead and its inorganic compounds (contained in air in the inhalable fraction of aerosol) on a membrane filter, filter mineralization with concentrated nitric acid and dihydrogen dioxide, and deter-mining lead in a solution prepared for analysis with flame atomic absorption spectrometry with atomiza-tion in air-acetylene flame (F-AAS).
This method enables determination of lead in the concentration range 0.25–10.00 μg/ml. The obtained calibration curve has a high correlation coefficient (R2 = 1.0000). The detection limit for lead (LOD) is 0.02 μg/ ml and the limit of quantification (LOQ) is 0.07 μg/ ml. Determined coefficient of recovery is 0.99.
The developed method enables determination of concentrations of lead and its inorganic compounds in the inhalable fraction in workplace air in the concentration range 0.0035–0.139 mg/m3 (for a 720-L air sample), which represents 0.07–2.8 of NDS and 0.0052–0.208 mg/m³ (for a smaller air sample of 480-L), which represents 0.10–4.2 of NDS. The method is accurate, precise and it meets the requirements of Standard No. EN 482 for procedures for determining chemical agents. The method of determining lead and its inorganic compounds has been recorded as an analytical procedure (appendix).

Issues associated with the emission of chemical substances from diesel exhaust are still the subject of many studies that lead to, among others, the reduction of pollution and determination of their chemical composition. The International Agency for Research on Cancer (IARC) reclassified exhaust particles from diesel engines from group 2A (probably carcinogenic mixture) to group 1  (carcinogen for humans). According to GUS data from 2010, 480 thousand people were employed in the transport industry, while the number of people exposed to the diesel exhaust was a total of 20719.
The aim of this paper was to develop a method for determining carcinogenic polycyclic organic substances occurring in the fraction of fine particles emitted into the environment during the operation of vehicles with diesel engines.
Sioutas personal cascade impactor (SPCI) and a 13-tier low-pressure cascade impactor ELPI were used to collect the fraction of particles emitted into the environment. The best results are obtained when using teflon and aluminum filters for samples. The analysis of carcinogens including polycyclic aromatic hydrocarbons adsorbed on particular matter was performed with highperformance liquid chromatography with fluorescence detection in reverse phase.
Application of high performance liquid chromatography with fluorescence detection HPLC/FL makes it possible to determine 9 carcinogenic hydrocarbons in the concentration range of 0.0025–1.00 mg·l-1. The correlation coefficient of the calibration curve was 0.99.
The procedure for determining PAH present on fractions of particles emitted from engine exhaust gases with a commercial probe SPCI was developed on the basis of the results.