Introduction

Consumer spray products (CSPs) are commonly used chemicals intended to enhance indoor air quality1,2. Particularly, the use of CSPs has increased in various products, such as polishes, air fresheners, and coatings, which are commonly used by people in their daily life. However, despite their widespread use, concerns persist regarding the disclosure of all components within these products, particularly those that may pose health risks due to volatile organic compounds (VOCs)3,4.

CSPs can be classified into propellant type, which uses compressed air, and trigger type, which uses spray pressure for spraying. Among the two, because the propellant type uses compressed air, it has a stronger spray intensity and range compared to the trigger type. However, the use of compressed air in CSPs poses direct risks to human health, primarily employing blends of liquefied petroleum gases like propane or butane5. Liquefied petroleum gas, introduced by the Montreal Protocol in 1987 to replace chlorofluorocarbon gases as harmful gases within CSPs, contributes to indoor air pollution because of its use with compressed air, along with VOCs generated from the bulk of CSPs6,7. Such exposure can lead to respiratory illnesses, reduced lung function, and shortened life expectancy8,9. Moreover, exposure to high concentrations of VOCs can result in various symptoms, including fatigue, headaches, and dizziness, with the central nervous system10,11,12,13, liver14,15, kidneys16, and peripheral nervous system17,18 being particularly vulnerable.

Exposure to hazardous substances emitted from CSPs depends on factors, such as pressure, nozzle size, and nozzle shape. Importantly, VOC emissions are influenced by the airflow generated by CSPs, indicating that VOCs can impact air quality even at greater distances19. Propellant type products use compressed air to spray the bulk of CSPs; therefore, they have a stronger instantaneous spray force than triggers20. However, depending on the characteristics (such as viscosity and volatility) of the bulk substances, there may be differences in the distances that can be affected. In propellant type products, VOCs may be evaporated, as particles are formed during spraying, whereas in trigger-type products, VOCs may not immediately evaporate but could do so later on.

Most studies on VOCs related to CSPs have primarily focused on the components within the products or the quantities of VOCs generated during their use21,22. However, owing to the nature of VOCs, their impact extends beyond specific distances due to diffusion, affecting not only those within proximity but also individuals in the same environment. Therefore, this study aimed to measure the concentration of VOCs at different distances from the point of spraying, categorized by product type and spraying method.

Methods

Air sampling and experimental protocol

The experimental procedure was conducted in a 40 m3 clean room (7.0 m (L) × 2.4 m (W) × 2.4 m (H)). The clean room was designed to allow air to pass through an activated carbon filter to remove VOCs while the air conditioning system operated. CSPs were sprayed and measured at a height of 1.5 m using an adjustable desk. VOC measurements were taken at distances of 1 and 3 m from the center of the desk. Tenax TA (0.25 × 3.5 mm, Tenax TA 60/80, Supelco, USA) was used at a flow rate of 0.05 L/min for sampling VOCs. The collected air samples were analyzed using thermal desorption–gas chromatography–mass spectrometry (TD–GC–MS, Chromatec, Russia)23. Analytical condition and parameter for VOCs analysis by TD–GC–MS were shown in Table S1. Figure 1 was a schematic of the experimental procedure. LOQ and recovery data were shown in Table S2.

Figure 1
figure 1

Schematic of the progression of the entire experiment.

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Before the experiment, the clean room was ventilated for 3 h using the air conditioning system. Subsequently, all air conditioning systems were turned off and background concentrations were measured at 1 m for 40 min. The acquired background sample was immediately frozen, and both 1 m and 3 m samples were used to measure the VOCs. Later, the CSPs were sprayed and measured for 180 min. The number of CSP sprays varied depending on the product purpose; therefore, we referred to the Korea Exposure Handbook, and the amount of product sprayed per experiment is shown in Table 1. Later, all samples were frozen and ventilated using an air-conditioning system. Moreover, the pollutants generated by spraying the CSPs were wiped clean immediately after each measurement.

Table 1 Information of tested spray products in experiment.
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Airborne VOC analytes by product group

A total of 47 CSPs used in the test were selected because they are available in the domestic market and their composition can be found online. Three product groups were selected: aromatic deodorant, antiseptic and disinfectant, and coating and polishing agents, which are prone to adverse health effects when used in limited spaces. Owing to the differences in the purpose of the CSPs, the substances to be measured in the air after spraying each product were selected differently for each group. First, the bulk of the advertised CSPs for each product group was analyzed using headspace GC–MS (7890A, Agilent, USA) (Table 1). Analytical condition and parameter for VOCs analysis by HS–GC–MS were shown in Table S3. The components in the analyzed bulk were classified according to the criteria of respiratory sensitization, inhalation toxicity, hazardousness, and International Agency for Research on Cancer Carcinogenicity classification and selected as airborne measurable substances. Eight substances each were considered in the antiseptic and insecticide group (benzene, toluene, ethylbenzene, xylene, 4-carvomenthenol, eucalyptol, linalool, and α-terpinyl acetate), coating and polishing agent group (benzene, heptane, toluene, octane, ethylbenzene, isopentane, xylene, and methylcyclohexane), and aromatic deodorant group (isopentane, ethyl acetate, isopropyl alcohol, benzene, toluene, ethylbenzene, xylene, d-limonene). The total VOC (TVOC) amount was calculated using toluene equivalent (EAP, 2023). All experiments were repeated three times to ensure the reliability of the results.

Statistical analysis

Statistical tests were performed using R software v4.0.3 (R Development Core Team, Vienna, Austria) to determine whether the airborne concentrations of the substances of each group by distance showed statistically significant differences. Normality was tested using the Shapiro–Wilk test, followed by the Kruskal–Wallis test. The Bonferroni method was used for post-hoc analysis, and statistical significance was set at p < 0.05. If the airborne concentration was less than the limit of detection (LOD), it was replaced by LOD/√2 and used in the statistics.

Results

Results of TVOC concentrations in three groups

Airborne TVOC concentrations in the three groups, determined according to the experimental procedure, are shown in Fig. 2. Upon spraying, the propellant type exhibited higher TVOC concentrations than the trigger type. The aromatic deodorant group using propellant-based products showed the highest TVOC concentration (13.89 ± 2.62 ppm) at a distance of 1 m. Furthermore, this group exhibited the highest TVOC concentration (9.14 ± 5.35 ppm) even at 3 m. Among the three groups, the antiseptic and insecticide groups had the lowest average concentration (1.19 ± 0.57 ppm). The coating and polishing agent group also showed low TVOC concentrations overall, but the propellant type had the highest concentration (9.26 ± 2.91 ppm) at 1 m, suggesting that using CSPs at relatively close distances can lead to high VOC exposure. However, due to the varying chemical compositions of the different product groups, it is hard to determine the extent of health effects based solely on TVOC concentrations.

Figure 2
figure 2

TVOC concentration of each spray group by distances.

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Common analyte concentrations in three groups

The airborne VOC concentrations of benzene, toluene, ethylbenzene, and xylene (BTEX), which were the same analytes in the three spray groups, are shown in Table 2. For the propellant type in the antiseptic and insecticide group, benzene and ethylbenzene concentrations were higher at 3 m (30.9 ± 25.6 and 8.1 ± 7.0 ppb, respectively) than at 1 m, while toluene concentrations were higher at 1 m (37.0 ± 18.7 ppb). Trigger type did not show a significant difference by distance, but toluene concentrations were high (21.8 ± 20.5 ppb) at 1 m.

Table 2 Air sampling results of BTEX for three product groups (ppb).
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The aromatic deodorant group exhibited low overall VOC concentrations with no significant differences at any distance. However, toluene showed a significantly higher concentration (p < 0.05, 15.7 ± 10.1 ppb) at 1 m when a propellant type product was used.

The coating and polishing agent group exhibited varying results for each substance. Benzene concentration in the propellant type product was high at 1 and 3 m (15.7 ± 13.1 and 15.1 ± 12.4 ppb, respectively), but did not show a significant difference by distance. Similarly, the benzene concentration in the trigger type products differed marginally at 1 and 3 m (31.0 ± 26.9 and 33.7 ± 30.7 ppb, respectively). However, toluene concentrations were high (16.6 ± 9.6 and 9.6 ± 9.2 ppb) at 1 m, regardless of the spray type.

VOC concentrations for each group, except BTEX

The results for the substances measured in the spray group, excluding BTEX, by distance are presented in Table 3. First, among the four airborne analytes (4-carvomenthenol, eucalyptol, linalool, and α-terpinyl acetate) in the antiseptic and insecticide group, eucalyptol, linalool, and α-terpinyl acetate showed significantly higher results at both 1 and 3 m in the propellant type, although their concentrations differed slightly by distances. In the trigger type, α-terpinyl acetate exhibited the highest concentration at 1 m, while its lowest concentration was of 1.1 ± 1.0 ppb.

Table 3 Air sampling results of VOC for each product group (ppb).
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In the aromatic deodorant group, four substances (ethyl acetate, isopentane, isopropyl alcohol, and d-limonene) were analyzed. Among these, isopropyl alcohol showed the highest concentration at 4620.2 ± 3006.1 and 1460.9 ± 330.5 ppb at 1 and 3 m, respectively, among the propellant type results. However, due to the higher background concentration of VOCs compared to other airborne VOCs, other factors may interfere, suggesting that propellant-type products may lead to high exposure concentrations. In the trigger type, the isopropyl alcohol concentration at 1 m was 1697.3 ± 330.5 ppb, which was significantly higher than the background concentration, but it was 179.8 ± 86.8 ppb at 3 m, which was similar to the background concentration.

Finally, in the coating and polishing agent group, four substances were analyzed (heptane, isopentane, methylcyclohexane, and octane). For the propellant type, concentrations were higher at 1 than at 3 m in this group. In contrast, in the trigger type, higher concentrations were observed at 3 m for all substances, except octane. Isopentane showed the highest concentration at 1 m in the propellant type (967.7 ± 370.3 ppb), while those of octane and heptane were 735.6 ± 191.5 and 734.8 ± 193.3 ppb, respectively. The trigger type exhibited lower concentrations than the propellant type, with the highest being methylcyclohexane at 3 m (356.1 ± 21.1 ppb). These two substances are frequently used as organic solvents, and are believed to contribute to airborne concentrations.

Proportion of airborne analytes in TVOC

The proportion of the total concentration of the measured airborne substances in the TVOCs for each spray group is shown in Fig. 3. In the antiseptic and insecticide group, most cases did not exceed 10% of the TVOCs, with the highest proportion being 10.8% in the propellant type at 3 m. The aromatic deodorant group showed a higher background signal than the other two groups because of the presence of isopropyl alcohol. This contributed to a higher proportion of the analyte in the results for each distance, in addition to the background. The highest proportion was (49.1%) at 1 m among the trigger types, and 30.3% at 3 m. In the coating and polishing agent group, the overall proportion of the analytes at 3 m was high. Specifically, the proportion of VOCs was 60.9% for the propellant type and 52.9% for the trigger type, both of which were higher than the proportions at 1 m.

Figure 3
figure 3

Proportion of analytes in TVOC. “Others” refers to ingredients (substances present in the bulk), excluding airborne analytes analyzed by the spray group. The numbers in the bar represent the proportion of airborne analyte concentrations among TVOCs by each condition.

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Discussion

This study evaluated the exposure to VOCs by distance when using different CSPs. Previous studies have majorly focused on how the use of CSPs changes indoor air quality or simulates specific environments. Generally, the use of CSPs is characterized by the diffusion of VOCs not only in close proximity to the user but also in the surrounding environment of the user. Therefore, in this study, the exposure to VOC concentrations were measured at different distance during CSP use.

Significant differences were observed between the substances listed on the CSP labels and the actual components in the bulk. In most cases, the labels specified purified water and fragrance, and in some cases, the components were not listed on the label. Consequently, products were selected based on their purpose. Notably, consumers were not aware of the possible harmful effects caused by using CSPs24,25. This is because, when a company makes and sells a product, the materials are listed on the label for substances used in a certain amount or more. Among various CSP products, studies have also reported that the listed ingredients on cleaning product labels differ from the actual exposure ingredients26. By listing all hazardous substances that can be generated through the usage of CSPs can provide a safe environment for consumers.

The aromatic deodorant group, which used the least amount of product on average, had the highest TVOC concentration (13.89 ± 2.62 ppm), while the antiseptic and insecticide group had the lowest TVOC concentration relative to the amount of product used. Both spray groups with high TVOC concentrations contained fragrances (or limonene) in both label and bulk results. These results may be attributed to the highly volatile nature of fragrances and an immediate effect upon application; moreover, the purpose of the product was to use the behavior of the ingredient. The coating and polishing agent group showed a difference in usage of 3.8–7.9 times compared to the aromatic deodorant group. This difference could be attributed to the varying amount of product released per spray. The total number of sprays differed marginally, with the CSPs in the coating and polishing agent group sprayed relatively less, while those in the aromatic deodorant group were sprayed widely. These results showed that the wider the spray type used by consumers, the higher the concentration that can be exposed. In addition, it was revealed that the exposure concentration did not increase only by using the spray. Part of the reason that only 26.1 ± 20.4% of total TVOCs were detected when using Tenax TA may be because the adsorbent did not capture various unknown components well. Although multi-bed Tenax TA was used to address this issue, it may have been insufficient to capture all components of TVOCs with various functional groups23. Additionally, the real-time measuring instrument is calibrated based on isobutylene, and since each substance has different reactivity, there will be corresponding differences.

Among the analyzed BTEX in all three spray groups, toluene had the highest concentration (37.0 ± 18.7 ppb) at 3 m of the propellant type in the antiseptic and insecticide group. In all three groups of propellant type products, toluene exhibited significantly higher concentrations at 1 m than in the background. This can be attributed to the volatile nature of toluene, which is mainly maintained at low heights. Benzene also showed significantly higher concentrations than the background in propellant products in the antiseptic and insecticide and coating and polishing agent groups. Benzene is regulated by the 2023 American Conference of Governmental Industrial Hygienists notice of intended change as a threshold limit value with a time-weighted average of 0.02 ppm27. The results showed that the benzene concentration in the propellant type in the antiseptic and insecticide group and the trigger type in the coating and polishing agent group exceeded this standard. However, while concentrations were high for some products, others remained below the threshold limit value-time-weighted average. Therefore, caution should be exercised when using products that may emit benzene, as continuous exposure to low concentrations of benzene can cause chromosomal structural abnormalities28. Ethylbenzene and xylene were rarely detected except when the product containing these substances was sprayed. Nevertheless, even though the concentrations of these substances that may be emitted into the air during CSP use are low and known to cause harmful effects on human, it should be noted that the actual use of the product varies depending on the amount of product used by each individual. Adverse health effects can occur with continuous exposure in environments with limited ventilation.

In the antiseptic and insecticide group, linalool and α-terpinyl acetate were predominant, while d-limonene and ethyl acetate were predominant in the aromatic deodorant group, and isopentane and octane were predominant in the coating and polishing agent. Linalool, a monoterpene, has been used as an insecticide29,30. In the trigger type, the airborne linalool concentrations were low, but in the propellant type, linalool and α-terpinyl acetate concentrations were high (10.9 ± 7.2 and 46.9 ± 28.2 ppb, respectively). Additionally, as a highly volatile substance, linalool can directly damage the respiratory system. The d-limonene concentration in air was 33.5 ± 19.5 ppb at 3 m for the propellant type and 28.8 ± 12.1 ppb at 1 m for the trigger type. d-Limonene is a typical fragrance ingredient often used in products for scenting indoor spaces. In aqueous solutions, d-limonene can cause gastrointestinal disruption and reduced absorption across cell membranes2. Therefore, direct spraying of CSPs onto the body, especially the respiratory system, and prolonged exposure is not recommended. Finally, isopentane and octane, which are commonly found in coatings and polishing agents, are used as solvents and may have a significant impact on airborne concentrations. Isopentane is highly volatility, and in the propellant type products, it volatilized on spraying and showed a high concentration at 1 m. In contrast, in the trigger type products, isopentane remained as a solution and volatilized later; additionally, it showed a high concentration at 3 m. As a result, volatilization in trigger type products has a large impact on the airborne concentration. As such, the highly volatile substances in trigger type products may volatilize later, requiring sufficient ventilation after use.

In terms of analyte concentration/TVOC values, the antiseptic and insecticide group accounted for marginal TVOC concentrations, the aromatic deodorant group exhibited a high concentration at 1 m (60.9%), regardless of the spray type, and the coating and polishing agent group showed a high concentration at 3 m (52.9%). This difference may be due to variations in ingredients based on the product’s purpose. Antiseptic and insecticide group products can be exposed through breathing and skin; however, products with small-scale targets had less impact on humans, which led to the low proportion of the measured substances in the TVOCs. Contrastingly, the aromatic deodorant group had higher overall TVOC concentrations, but the high proportion of measured substances indicated a higher risk of exposure to these substances. Particularly, the products in the aromatic deodorant group are generally used for long periods; therefore, careful attention should be paid to the management of indoor air quality. Finally, in the coating and polishing agent group, the proportion of measured substances was high at 3 m, indicating that VOCs could be generated continuously until a little later, rather than immediately after the product was used. Particularly, the range of influence of trigger-type products is narrower than that of propellant-type products, but a risk of concentrated exposure to the solution exists because they are often used at close range31. Therefore, the use of these products in ventilated environments is recommended.

Since VOCs concentrations were compared at a fixed location in a clean room and at different distances (including model results such as ConsExpo), the concentrations observed may not reflect those in real-world usage scenarios32. For example, if a product from the deodorant group is sprayed directly onto clothing, the distance may be shorter than 1 m, resulting in exposure to higher VOCs levels than those measured in this experiment. Furthermore, the risk of direct spraying onto the human body and the use of protective equipment during the use of CSPs may affect the concentration of hazardous substances generated by CSPs. In this study, a typical spraying environment was simulated, which is appropriate given the wide variety of spray products available on the market. Finally, the VOC concentrations at different distances were identified during CSP use to evaluate potential exposure levels.

Conclusion

In this study, the VOC concentrations generated by each spray group when using CSPs were measured by distance. Benzene was measured in the antiseptic and insecticide group, as well as the coating and polish agent group, with concentrations of up to 30.9 ± 25.6 ppb for the propellant type and 33.7 ± 30.7 ppb for the trigger type. However, only products containing benzene were included in these results, underscoring the importance of comprehensive labeling of hazardous ingredients. The concentration of TVOCs in the aromatic deodorant group was the highest and lowest in the antiseptic and insecticide group. Analyte/TVOC levels were higher in the aromatic deodorant group (maximum 49.1%) and coating and polishing agent group (maximum 60.9%), indicating significant volatility of substances in these products. Due to varying usage purposes across product groups, direct spraying on the body may elevate the risk of exposure to these volatile substances. Therefore, it is recommended to pay attention to the environment in which CSPs are used, particularly in small confined areas with limited ventilation, as these conditions can exacerbate the diffusion of VOCs and pose substantial health risks.