Formaldehyde Content Research Articles

Online real time determination of free formaldehyde content during polymerization process of phenolic resin by NIR spectra and a modeling-free method

Real time detection of free formaldehyde content during synthesis process of phenolic resins is of great significance for controlling the quality of resin products. In this paper, we proposed a method of near infrared (NIR) spectroscopy combined with multivariate curve resolution-alternating least squares (MCR-ALS) to online real time detect free formaldehyde content during the synthesis process of phenolic resins. The absorption band of CH bonds in formaldehyde was extracted by MCR-ALS from the overlapped absorption bands of CH bonds in phenol, formaldehyde and intermediate products, and is directly utilized to monitor free formaldehyde content during polymerization process. The calculated results of MCR-ALS are highly consistent with those obtained by the chemical titration method, which indicates this method is accurate. Compared with multivariate calibration commonly used for NIR, this method does not require modeling, and is more labor-saving and easier to spread in industrial production.

A new electroanalytical methodology for the determination of formaldehyde in wood-based products

A new electroanalytical methodology was developed for the sensitive and selective determination of formaldehyde in wood-based products (WBPs), featuring an extraction process using a Headspace Liquid Acceptor System (HLAS), and detection by square-wave voltammetry (SWV) on unmodified screen-printed carbon electrodes (SPCEs). HLAS, here presented for the first time, captures and derivatizes formaldehyde released from the sample by using the acetylacetone reagent as acceptor solution. The product of formaldehyde with acetylacetone, in the presence of ammonium salt, is 3,5-diacetyl-1,4-dihydrolutidine (DDL) which we have found to be electrochemically active at unmodified SPCEs, generating a selective oxidation peak at +0.4 V. Detection and quantification limits of 0.57 and 1.89 mg kg−1 were obtained, together with intra- and inter-day precisions below 10% (as relative standard deviation, RSD). The methodology was used to determine formaldehyde content in seven WBPs, with similar results being obtained by the developed HLAS-SPCE method and the European standard method EN 717–3, with a profound reduction of total analysis time.The developed HLAS-SPCE combines the use of a new sample preparation procedure for volatiles with, as far as we know, the first determination of formaldehyde (as the derivative product, DDL) on unmodified SPCEs, offering a promising alternative for the determination of formaldehyde in WBPs and other samples.

Process modification involving strong-acid step in urea-formaldehyde resin preparation

Urea-formaldehyde (UF) resin adhesive for wood-based panel industries are commonly manufactured using conventional alkaline-acid process. This paper reports a process modification of a conventional UF resin preparation by incorporating a strong-acid step, involving simultaneous methylolation and condensation reactions at very low pH at the beginning of the processing step. The experiment showed that this additional step should be carried out at short duration and at high enough temperature in order to avoid gelation or separation problems. In order to control temperature rise caused by the exothermic nature of the reactions, the modified process requires a higher initial formaldehyde-to-urea (F/U) molar ratio compared to the original. For the same reason, the first urea should be fed incrementally to ensure high F/U ratio at any time during the strong acid step. Using regular formalin concentration as raw material at the same F/U molar ratio, the modified resin showed lower free formaldehyde content thus have lower reactivity in comparison to those of the original. However, when the same procedure was applied using higher formaldehyde concentration at higher solid content, the produced resin showed comparable free formaldehyde content and shorter gelation time. Application test for making plywood showed that the modified process gave a very significant improvement in both the internal bonding strength and formaldehyde emission.

Use of Hardwood Species (Robinia pseudoaccacia from Short-rotation Plantations as Raw Material in Particleboards

The problem of climate change, coupled to the propagation of wood diseases (bark beetles for example), is leading to a shortage in softwood supply for the particleboard industries. Furthermore, the recent changes in the German forest policies which promote the conversion of coniferous forest into mixed stands are likely to enhance this phenomenon. There is, therefore, a growing need for research on possibilities of substituting the softwood with hardwood and other alternative material. For the first time, young six to seven years old Black locust (Robinia pseudoaccacia) stems from a short-rotation plantation were used at a laboratory scale with the objective of assessing the suitability of particleboard production. Four different variants were produced using different resin types: UF K350, UF K340, albumin, and PMDI, with a target density and thickness of 650 kg/m3 and 20 mm respectively for each board. The boards were tested regarding their mechanical (modulus of rupture, modulus of elasticity and internal bonding), physical (water absorption and thickness swelling) properties according to the European standard (EN 310, EN 317 and EN 319), and their formaldehyde content and emission following the EN 120 and EN 717. Industrial particles were used as reference material for the purpose of comparison. Promising bending strength was obtained with UF resins-bonded boards. The modulus of elasticity of all four variants fulfilled the EN 2003 requirements. The internal bond of the UF resins-bonded boards also met the general product standard, with values above 0.35 N/mm2. The bending strength and the internal bonding strength properties of the UF-bonded boards were superior to that of the reference boards produced with the industrial particles. Based on these results, black locust is a potential substitute for softwood in particleboard production and can be used in the industry as alternative raw material for panel production.

Formaldehyde formation during the preparation of dialdehyde carboxymethyl cellulose tanning agent

Formaldehyde was detected in dialdehyde carboxymethyl cellulose (DCMC) tanning agent prepared through periodate oxidation of sodium carboxymethyl cellulose (CMC). Formaldehyde was then introduced into leather through DCMC tanning, which poses a potential risk to human health. The formation mechanism of formaldehyde in DCMC was investigated by composition analysis and intermediate identification of DCMC with different polymerization degrees and sugar unit structures. Formaldehyde was derived from the overoxidation of C-6 on the reducing glucose residue of CMC. Moreover, glucose was produced from the concomitant degradation of CMC during oxidation, and then oxidized to liberate formaldehyde. The low degradation degree and high degree of substitution of CMC reduced the possibility of the formation of reducing glucose residue and glucose during oxidation, thereby resulting in low formaldehyde content in DCMC and DCMC-tanned leather. These findings serve as a foundation for the minimization of formaldehyde in DCMC and the development of ecological tanning approach.

Determination of Formaldehyde Content by High Performance Liquid Chromatography in Some Fruits of Local Market in Dhaka City, Bangladesh

The present study was conducted to determine the formaldehyde content in three mostly consumed fruits (mango, apple and grape) in Bangladesh. A total of 81 samples were collected from three different local markets of Dhaka city (Mohammadpur Bazaar, Mohakhali Bazaar and Gulistan Bazaar). High Performance Liquid Chromatography (HPLC) with c-18 column and UV detector at 355 nm were used to determine the formaldehyde content. The mobile phase was 50% acetonitrile with a flow rate 1ml/min. The concentration of formaldehyde in mango was from 1.86mg/100g to 11.65mg/100g in Mohammadpur Bazaar, 1.45mg/100g to 10.69mg/100g in Mohakhali Bazaar and 1.69mg/100g to 4.41mg/100g in Gulistan Bazaar. It was found that 2.28mg/100g to 7.30mg/100g, 2.33mg/100g to 11.77mg/100g & 1.42mg/100g to 5.39mg/100g formaldehyde contained in apple for Mohammadpur, Mohakhali, Gulistan Bazaar respectively. Among the selected sample, the content of formaldehyde in grape was lower than mango and apple. The amount of formaldehyde in grape was 0.93mg/100g to 4.63mg/100g, 1.92mg/100g to 3.84mg/100g & 1.42mg/100g to 4.92mg/100g for Mohammadpur, Mohakhali, Gulisthan market. The highest formaldehyde concentrations (11.77mg/100g) were detected in apple fruit, exceeding the naturally found permissible limit of 0.63 to 2.23 mg/100gm; the second highest formaldehyde concentration (11.65mg/100g) were found in mango, exceeding the permissible limit of 0.1 to 6 mg/100gm; while the grape also contains high level of formaldehyde concentration (4.92mg/100g) exceeding the permissible limits 2.24mg/100gm. It was surprisingly found that the 22.22% of mango, 85.19% of apple and 66.67% of grape contained formalin above the permissible limit. Keywords: Fruits, Formaldehyde, HPLC, Food Safety DOI: 10.7176/FSQM/96-06 Publication date: April 30 th 2020

Synthesis of Formaldehyde Free Amino Resin to Produce Green Eco-Labelled Leather with Improved Retanning Properties

Formaldehyde has many applications in the chemical industry including synthesis of amino resins which are used in leather processing. After application in leather, these resins are hydrolyzed under certain conditions to release free formaldehyde which has high environmental concerns due to its proven carcinogenic effects. The objective of this work is to develop a formaldehyde free melamine-based resin to produce green leather with improved retanning properties and thermal stability. The optimum melamine resin was synthesized by condensing melamine with glyoxal instead of formaldehyde. Further, the water solubility and improved thermal stability of synthesized melamine resins were achieved by introduction of sulfanilic acid in resin structure. Synthesized resin was used in leather retanning in comparison with commercially available melamine resin as a control. Both leathers were tested for mechanical properties, organoleptic properties, grain surface and fiber structure analysis. Comparative free formaldehyde content was measured in resultant leathers. Effluents of retanning baths were comparatively analyzed. Optimum resin was also characterized by thermo gravimetric analysis and FTIR. The results of this study showed that the experimental resin has imparted significant improvement in mechanical and organoleptic properties of leather as compared to the control resin. Analysis of free formaldehyde content confirmed the absence of free formaldehyde in leather treated with optimum resin while 141 mg/kg formaldehyde was detected in leather treated with control resin. Free formaldehyde was also absent in effluent of experimental resin while 305 mg/kg formaldehyde was detected in effluent of control resin. Moreover, percentage efficiency in COD, TDS and TSS load of effluent was observed as 9.62, 7.2 and 6.31 respectively. Resultant leather was free from formaldehyde making it safe for human along with reduction in pollution load of tannery.

Seasonal variation of background formaldehyde content in large squid from scientific research research vessel

The background formaldehyde (FA) in large squid is determined through high performance liquid chromatography (HPLC). Its seasonal variation was further investigated. In autumn and summer, background FA content in Todarodes pacificus was higher, with the mean value up to 36.8 mg/kg in September. This study provide scientific data for the monitoring management of FA during the circulation and sale of squid.

Synthesis of micro carbonaceous material by pyrolysis of rubber wood and its effect on properties of urea-formaldehyde (UF) resin

Micro sized carbonaceous materials were synthesized by pyrolysis of rubber wood fibers and their dispersion in urea formaldehyde (UF) was investigated. The carbonaceous material reinforced in UF has been prepared with a weight concentration up to 5%. The uniform dispersion of the carbonaceous material in the UF was achieved by mechanical stirring. All resin hybrids were characterized by solution rheology, Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffractometry (XRD) while the dispersion of carbonaceous materials was analyzed by scanning electron microscopy (SEM). FTIR spectroscopy results showed that carbonaceous materials can make hydrogen bonds with UF resins. The X-ray-based measurement of the crystallinity index (CrI) indicated that carbonaceous material increased the crystallinity of UF resin, whereas the maximum value of CrI was observed at UF-1 i.e., 85.7%. Curing reactions were examined with differential scanning calorimetry (DSC), and it was observed that the curing temperature of UF resin is affected by the addition of carbonaceous materials. Thermo-gravimetric analysis (TGA) revealed that carbonaceous materials have little effect on the thermal stability of the resin. Wood particleboards were fabricated and their performance was measured. The internal bonding strength and the modulus of rupture were measured for the particle boards, and a maximum at a 1% weight concentration was observed. The formaldehyde content of particle boards decreased with the addition of carbonaceous materials. At a 1% weight concentration, a maximum reduction of formaldehyde content was obtained using the perforator method.

Formaldehyde as a Chemical Defence Agent of Fruiting Bodies of Mycena rosea and its Role in the Generation of the Alkaloid Mycenarubin C.

Mycenarubin C, a previously unknown red pyrroloquinoline alkaloid, was isolated from fruiting bodies of the mushroom Mycena rosea and its structure was elucidated mainly by NMR spectroscopy and mass spectrometry. Unlike mycenarubin A, the major pyrroloquinoline alkaloid in fruiting bodies of M. rosea, mycenarubin C, contains an eight‐membered ring with an additional C1 unit that is hitherto unprecedented for pyrroloquinoline alkaloids known in nature. Incubation of mycenarubin A with an excess of formaldehyde revealed that mycenarubin C was generated nearly quantitatively from mycenarubin A. An investigation into the formaldehyde content of fresh fruiting bodies of M. rosea showed the presence of considerable amounts of formaldehyde, with values of 5 μg per gram of fresh weight in fresh fruiting bodies. Although mycenarubin C did not show bioactivity against selected bacteria and fungi, formaldehyde inhibits the growth of the mycoparasite Spinellus fusiger at concentrations present in fruiting bodies of M. rosea. Therefore, formaldehyde might play an ecological role in the chemical defence of M. rosea against S. fusiger. In turn, S. fusiger produces gallic acid—presumably to detoxify formaldehyde by reaction of this aldehyde with amino acids and gallic acid to Mannich adducts.

Adverse health risk from prolonged consumption of formaldehyde-preserved carps in eastern region of Indian population.

Presence of formaldehyde as a preservative in commonly available fishes (Labeo rohita, Catla catla, Anabas testudineus and Clarias gariepinus) has become a serious health concern in the public health of eastern region of India. Formaldehyde content was determined using high-performance liquid chromatography (HPLC). Results showed high formaldehyde content in frozen carp (19.66 and 23.3mg/kg in Labeo rohita and Catla catla, respectively); however, the amount of formaldehyde was significantly reduced in boiled and fried fish (80°C and 100°C for 5min) in mustard, coconut, and sesame oils. However, formaldehyde contents in non-carp fishes (Anabas testudineus and Clarias gariepinus) were almost negligible, compared to those in L. rohita and C. catla. In vivo toxicity studies showed a time-dependent increase in blood formaldehyde levels in rats after they were fed formaldehyde-contaminated fish (23.3mg/kg) for 7days. Histopathological analysis of the stomach of rats fed contaminated fish showed destruction and granulation of the protective mucus layer and detachment from the secretory layer. Taken together, our results indicated that continuous consumption of formaldehyde-contaminated carps commonly available in the eastern region of India may be associated with adverse health effects.

Preparation and Properties of Five Biomass-based Melamine Modified Urea Formaldehyde Resins

In this paper, shell (PS), rice husk (RH), rapeseed stalk (RS), toonaciliata wood (TW) and Sinocalamus affinis (SA) were served as the modifier to modify the melamine modified urea-formaldehyde resin (MUF). The PS, RH, RS, TW, SA were ultra-fine crushed to be the powder with less than 48 um. The reactivity of PS, RH, RS, TW, SA and formaldehyde solution was measured, and PS, RH, RS, TW, SA were added in the third stage of synthesis process of the MUF resin. The basic properties of the resin and plywood were tested. The results showed that, with addition of the PS, RH, RS, TW, SA, the reactivity with formaldehyde solution became better, while the gel time became longer, the resin viscosity and the solid content increased, and the free formaldehyde content of the resin decreased. The formaldehyde emission of the plywood decreased by 60.53%, 48.25%, 41.23%, 44.74%, 56.14%, respectively, and the wet ply strength of the plywood increased by 40.00%, 56.19%, 16.19%, 24.76%, 54.29%, respectively. The use of the ultra-fined PS, RH, RS, TW, and SA showed good effects on the formaldehyde elimination of the MUF resin.

Effects of Three Biomass Fillers on the Properties of Melamine Modified Urea-Formaldehyde Resin

In this paper, the ultra-pulverized walnut shell (WS), walnut dregs (WD), and tea (T) were blended with formaldehyde solution. Based on the determination of the reactivity of WS, WD, T and formaldehyde solution, WS, WD, T was respectively blended with melamine modified urea-formaldehyde resin (MUF) as fillers, and the properties of the resin and plywood were analyzed. The results showed that under the conditions of blending, the pot life and gel time of MUF resin are prolonged, the viscosity is increased, while the pH value, the free formaldehyde content and the methylol content are decreased. The formaldehyde emission of the prepared plywood decreased with the amount of WS, WD, and T increased. When the added amounts of WS, WD, and T were 30%, 30%, and 10%, respectively, the wet bond strength of plywood increased by 120.00%, 47.27%, and 50.91%, respectively. The optimal amount of WS, WD, and T is 20%, 30%, and 10%.

High-value utilization of hydroxymethylated lignin in polyurethane adhesives

Lignin is a good candidate for the polymerization and chemical modification to prepare sustainable chemicals and materials, but a relatively low hydroxyl content becomes an obstacle for the preparation of lignin-based polyurethane (PU) adhesives. In order to improve its reactivity, the acetic acid lignin (AAL) was hydroxymethylated before copolymerized with isocyanate during the preparation of PU adhesives. The hydroxymethylation was carried out in an alkaline formaldehyde solution and it was found that 85 °C is the optimal temperature. On that condition, the free formaldehyde content of the corresponding product HL-6 was as low as 0.32%, while the hydroxymethyl was increased by 189.11% compared with original AAL and reached 2.92 mmol/g. In the polymerization of PU adhesives, the hydroxymethylated lignin with a higher aliphatic hydroxyl content formed a more compact three-dimensional urethane cross-linking network with isocyanate. The mechanical properties and thermal stability of the lignin-based PU adhesive were improved by 15–30 wt% in HL-6, and particularly the tensile strength was increased by 21–41 MPa, which indicated that the hydroxymethylation is an efficient way to enrich the hydroxyl in lignin, and the modified lignin is adequate to partially replace petroleum-based polyols for the preparation of PU adhesives with excellent properties.

Evaluation and analysis of volatile organic compounds and formaldehyde emission of building products in accordance with legal standards: A statistical experimental study

Building materials have been developed mainly for thermal performance, strength, low energy consumption, and aesthetics. Consequently, large amounts of chemicals have been added to building products, resulting in the release of abundant pollutants that adversely affect human health. In particular, pollutants from the materials used to build modern dwellings can cause sick house syndrome, which leads to health resilience problems and diseases. In this study, more than 100 investigations were conducted annually from 2004 to 2017 by using the 20 L small chamber method to analyze the contents of formaldehyde (HCHO) and total volatile organic compounds (TVOC) released from 2780 building products in total. High emissions were released by some building components with raw materials containing hazardous chemicals. However, since the 2004 enactment of a legal standard for the regulation of emissions of harmful substances in building products, the pollutant emissions have tended to decrease over the years. As a result of the experiment, all 2780 building materials met the legal standard on average. Therefore, legal restrictions on the release of hazardous materials from building products have achieved reductions in pollutant emissions.

Free formaldehyde reduction in urea-formaldehyde resin adhesive: Modifier addition effect and physicochemical property characterization

Melamine, polyvinyl alcohol, and adipic acid dihydrazide as modifiers were added to urea-formaldehyde (UF) resin for reducing the free formaldehyde. The influence of addition amount and addition stage of modifiers on the physicochemical property and free formaldehyde content of UF resin was tested. Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analyses (TGA) were used to determine the structural change and thermal stability of the resins. The results revealed that the UF resin added with 6% melamine had the lowest free formaldehyde content of 0.31%. Among all modified resins added with equal amount of modifier in different stages, the UF resin added with 3% polyvinyl alcohol in the second alkaline stage achieved the lowest free formaldehyde content of 0.33%. More importantly, the comprehensive effect of melamine, polyvinyl alcohol, and adipic acid dihydrazide on the free formaldehyde content of resin was studied. The free formaldehyde content in the UF resin added with the comprehensive modifiers achieved 0.24% content, and formaldehyde emission of this kind of adhesive was just 0.21 mg/g. Coupling the experimental results with the characterization data, comprehensive modifiers can reduce the formation of chemical bonds (methylene and ether bonds) in the resin and improve thermal stability of UF resin effectively.

A study of the influence of press parameters on particleboards’ performance

Nowadays, wood-based panel producers intend to lower costs by decreasing the pressing time and reducing resin consumption. Therefore, the aim of this work is to understand the influence of the pressing operating conditions (pressing time and pressing program) on the performance of particleboards (PBs) bonded with a UF resin (alkaline–acid process). For this purpose, several trials were carried out using a computer-controlled laboratory scale hot-press with a press cycle simulating a continuous press and a fixed position laboratory scale hot-press, varying the venting, the total pressing time ( 90 s) and the gluing factor (resin content—4, 5 and 6 mg resin solids/g oven dry wood). Analysis of variance (ANOVA) was performed in order to evaluate the significance level of the effects of these parameters on PB’s physico-mechanical properties and formaldehyde content. The main results of the study were: to decrease formaldehyde content, resin content (RC) should be increased for pressing times higher or equal to 90 s or decreased for pressing times lower than 90 s; to increase internal bond, RC must be increased for pressing times equal or higher than 90 s, or decreased for pressing times lower than 90 s.

Analysis of Larch-Bark Capacity for Formaldehyde Removal in Wood Adhesives.

Ecofriendly wood-based materials are required by consumers at present. Decorative panels are part of a large group of wood-composite materials, and their environmental properties must not be neglected. More environmentally friendly decorative panels can be achieved by various methods. This paper describes a method of production from larch bark. Tree bark, as a byproduct of the wood industry, is one of the research topics that have gained interest in the last decade, especially for its applications in biobased lignocomposites, with regard to the shrinkage of wood resources. In the present work, the formaldehyde content of decorative boards based on larch bark (0.6 g/cm3) was analyzed when bonded with five different types of adhesive systems: urea-formaldehyde, polyvinyl acetate, the mixture of 70% urea-formaldehyde + 30% polyvinyl acetate, polyurethane, and tannin-based adhesive. A self-agglomerated board was also analyzed. The formaldehyde content of the larch-bark samples was determined with the perforator method (EN 120:2011), and findings showed that all tested samples reached the E1 classification (≤8 mg/100 oven dry). Moreover, 75% of the values of the corrected formaldehyde content were included in the super-E0 class (≤1.5 mg/100 oven dry). In the case of boards bonded with tannin-based adhesive, this natural polymer acted as a formaldehyde scavenger.

Synthesis and Application of a Formaldehyde-free Flame-retardant for Cotton Fabrics by Polymerization between Diammonium Hydrogen Phosphate and Citric Acid

ABSTRACT Elimination of halogen and formaldehyde from flame-retardants is the focus of the recent research due to their adverse effects on the human health and the environment. This research investigates the numerous halogen-free and formaldehyde-free flame retardant recipes for cotton fabrics through polymerization between diammonium hydrogen phosphate (DAHP) and citric acid considering the effects of catalyst, initiator, temperature, normal atmosphere, inert atmosphere, and nitrogen atmosphere. Then, this research applies these nontoxic recipes on the cotton fabric samples and determines the char-length and char-width. The further analysis included the limiting oxygen index (LOI), crease recovery angle (CRA), air permeability retention, shrinkage, smoldering cigarette test, fourier transform infrared spectroscopy (FTIR) analysis, scanning electron microscope (SEM) analysis, energy dispersive X-ray spectroscopy (EDX), phosphorous concentration, and formaldehyde content in fabric. The newly proposed recipes exhibited similar or superior performance compared with formaldehyde-based commercial flame retardant, Pyrovatex.

Features of air pollution the cities of the North-Western Black Sea region

Introduction. According to official statistics, regions of Ukraine are characterized by a significant amount of pollutant emissions from stationary sources. But in many areas the dominant contribution to the formation of general levels of air pollution is made by mobile sources. Such regions include the Odessa, Mykolaiv and Kherson regions of the North-Western Black Sea. Regions of the North-Western Black Sea are characterized by a sufficiently high level of technogenic load and have a high recreational potential. This territory is characterized by unique natural resource potential. However, due to the development of urbanization processes, the impact of industrial, transport and agrarian sectors is worsening the overall environmental situation, including the state of the atmospheric air. Review of previous publications. The work of many authors is devoted to the question of the level of air pollution in the cities of the North-Western Black Sea. Most of the works are complex studies of the level of pollution of the regions of Ukraine as a whole. Some works are devoted to the assessment of the technogenic load on the environment of the regions of Ukraine. An analysis of recent research has shown that the vast majority of work is devoted to the regions of Ukraine as a whole. Also, the list of pollutants and the study period are quite limited. Usually, the content of the main pollutants is analyzed. At the same time, the content of specific pollutants is very important in the regions of the North-Western Black Sea in the formation of high levels of atmospheric pollution. Purpose. The purpose of this work is to evaluate and analyze the level of air pollution of individual cities of the North-Western Black Sea over a multi-year period. The complex atmospheric pollution index, which are currently one of the main indicators of atmospheric air quality, were used for the assessment. Results. The level of air pollution in Odessa is in most cases classified as "heavily polluted", Izmail – the only category "slightly polluted" (maximum concentrations in the air pool are marked by the content of formaldehyde). In Mykolayiv maximum concentrations with significant exceedances of the maximum permissible concentration are also noted for formaldehyde content, and the level of atmospheric air pollution was classified as "poorly polluted" – "contaminated". In Kherson, the highest content was observed for substances such as formaldehyde and nitrogen dioxide. The level of pollution, as in the city of Mykolaiv, was classified as "poorly contaminated" – "contaminated". Conclusions. Odessa, by the content of the vast majority of the pollutants, is in the category of cities with high levels of atmospheric pollution, Mykolaiv, Kherson and Izmail – in the category with the permissible level. The results of the study are the basis for the development of environmental recommendations for reducing the emissions of pollutants into the atmospheric air of the region, primarily from mobile sources.