Disposable sanitary pads are a necessity for women’s health, but safety concerns regarding the use of these products have created anxiety. The aim of this study was to conduct a risk assessment of 74 volatile organic compounds (VOCs), which were expected to be contained within sanitary pads. Of the 74 VOCs, 50 were found in sanitary pads retailed in Korea at concentrations ranging from 0.025 to 3548.09 µg/pad. In order to undertake a risk assessment of the VOCs, the toxicological database of these compounds in the United States Environmental Protection Agency (USEPA), Agency for Toxic Substances and Disease Registry (ATSDR), National Toxicology Program (NTP) and World Health Organization (WHO) was searched. Ethanol was found to exhibit the highest reference dose (RfD) while 1,2-dibromo-3-chloro-propane displayed the lowest RfD. Consequently, a worst-case exposure scenario was applied in this study. It was assumed that there was the use of 7.5 sanitary napkins/day for 7 days/month. In the case of panty liners or overnight sanitary napkins, the utilization of 90 panty liners/month or 21 overnight sanitary napkins/month was assumed, respectively. In addition, 43 kg, the body weight of 12 to 13-year-old young women, and 100% VOCs skin absorption were employed for risk assessment. The systemic exposure dose (SED) values were calculated ranging from 1.74 (1,1,2-trichloroethane) ng/kg/day to 144.4 (ethanol, absolute) µg/kg/day. Uncertainty factors (UFs) were applied ranging from 10 to 100,000 in accordance with the robustness of animal or human experiments. The margin of exposure (MOE) of 34 VOCs was more than 1 (acceptable MOE > 1). Applicable carcinogenic references reported that the cancer risk of five VOCs was below 10⁻⁶. Based on our findings, evidence indicates that the non-cancer and cancer risks associated with VOCs detected in sanitary pads currently used in South Korea do not pose an adverse health risk in women.

During the off-season, soccer players in Korea attend the winter training season (WTS) to build running stamina for the next season. For young soccer players, proper recovery time is needed to prevent injury or muscle damage. In this study, urinary metabolites in young players after 1, 5, and 10 days of the WTS were analyzed using nuclear magnetic resonance spectroscopy (NMR) combined with multivariate analysis to suggest appropriate recovery times for improving their soccer skills. After NMR analysis of the urine samples obtained from young players, 79 metabolites were identified, and each group (1, 5, or 10 days after WTS) was separated from the before the WTS group in the target profiling analysis using partial least squares-discriminant analysis (PLS-DA). Of these, 15 metabolites, including 1-methylnicotinamide, 3-indoxylsulfate, galactarate, glutamate, glycerol, histamine, methylmalonate, maltose, N-phenylacetylglycine, trimethylamine, urea, 2-hydroxybutyrate, adenine, alanine, and lactate, were significantly different than those from before the WTS and were mainly involved in the urea, purine nucleotide, and glucose-alanine cycles. In this study, most selected metabolites increased 1 day after the WTS and then returned to normal levels. However, 4 metabolites, adenine, 2-hydroxybutyrate, alanine, and lactate, increased during the 5 days of recovery time following the WTS. Based on excess ammonia, adenine, and lactate levels in the urine, at least 5 days of recovery time can be considered appropriate.

The chemical 4-amino-3-nitrophenol (4A3NP) is classified as an amino nitrophenol and is primarily utilized as an ingredient in hair dye colorants. In Korea and Europe, it is exclusively used in non-oxidative or oxidative hair dye formulations, with maximum allowable concentrations of 1% and 1.5%, respectively. Despite this widespread use, risk assessment of 4A3NP has not been completed due to the lack of proper dermal absorption data. Therefore, in this study, both the analytical method validation and in vitro dermal absorption study of 4A3NP were conducted following the guidelines provided by the Korea Ministry of Food and Drug Safety (MFDS). Before proceeding with the dermal absorption study, analytical methods were developed for the quantitation of 4A3NP through multiple reaction monitoring (MRM) via liquid chromatography-mass spectrometry (LC-MS) in various matrices, including swab wash (WASH), stratum corneum (SC), skin (SKIN, comprising the dermis and epidermis), and receptor fluid (RF). These developed methods demonstrated excellent linearity (R² = 0.9962–0.9993), accuracy (93.5–111.73%), and precision (1.7–14.46%) in accordance with the validation guidelines.The dermal absorption of 4A3NP was determined using Franz diffusion cells with mini-pig skin as the barrier. Under both non-oxidative and oxidative (6% hydrogen peroxide (H₂O₂): water, 1:1) hair dye conditions, 1% and 1.5% concentrations of 4A3NP were applied to the skin at a rate of 10 μL/cm², respectively. The total dermal absorption rates of 4A3NP under non-oxidative (1%) and oxidative (1.5%) conditions were determined to be 5.62 ± 2.19% (5.62 ± 2.19 μg/cm²) and 2.83 ± 1.48% (4.24 ± 2.21 μg/cm²), respectively.

Pyrogallol is an ingredient in hair dye. Its concentration in hair dye is managed at less than 2.0% in Korea. There have been no reports on the dermal absorption rate of pyrogallol. The two purposes of this study were to develop an analytical method and determine the dermal absorption rate of pyrogallol. An analytical method was developed and validated by high-performance liquid chromatography (HPLC) analysis of various matrices including swabs (SWAB), skin (SKIN, dermis + epidermis), stratum corneum (SC), and receptor fluid (RF). Linearity (r² = 0.9993–0.9998), accuracy (92.1–108.2%), and precision (0.5–9.5%) met the validation criteria in guidelines. A Franz diffusion cell was used to determine the dermal absorption of pyrogallol using the skin of mini pigs. Pyrogallol (2.0%) was applied to the skin (10 μL/cm²). For the actual hair dye conditions, the skin was wiped with a swab 30 min after application. Twenty-four hours later, it was wiped with a swab again and the SC was collected using tape stripping. All samples were extracted with water and analyzed. RF was recovered at 0, 1, 2, 4, 8, 12, and 24 h. The total dermal absorption rate of pyrogallol was determined to be 26.0 ± 3.9%.

The cosmetic industry has flourished in recent years. Accordingly, the safety of cosmetic ingredients is increasing. Bromochlorophene (BCP) is a commonly used cosmetic preservative. To evaluate the effects of BCP exposure, in vitro dermal absorption and in vivo pharmacokinetic (PK) studies were conducted using gel and cream formulations. The Franz diffusion cell system and rat dorsal skin were used for tests according to the Korea Ministry of Food and Drug Safety guidelines for in vitro skin absorption methods. After the dermal application (1.13 mg/cm²) of BCP in the gel and cream formulations, liquid chromatography–mass spectrometry (LC–MS/MS) was used to evaluate the amount of BCP that remained unabsorbed on the skin (WASH), and that was present in the receptor fluid (RF), stratum corneum (SC), and (epi)dermis (SKIN). The total dermal absorption rate of BCP was 7.42 ± 0.74% for the gel formulation and 1.5 ± 0.9% for the cream formulation. Total recovery in an in vitro dermal absorption study was 109.12 ± 8.79% and 105.43 ± 11.07% for the gel and cream formulations, respectively. In vivo PK and dermal absorption studies of BCP were performed following the Organization for Economic Cooperation and Development guidelines 417 and 427, respectively. When intravenous (i.v.) pharmacokinetics was performed, BCP was dissolved in glycerol formal and injected into the tail vein (n = 3) of the rats at doses of 1 and 0.2 mg/kg. Dermal PK parameters were estimated by the application of the gel and cream formulations (2.34 mg/kg of BCP as an active ingredient) to the dorsal skin of the rats. Intravenous and dermal PK parameters were analyzed using a non-compartmental method. The dermal bioavailability of BCP was determined as 12.20 ± 2.63% and 4.65 ± 0.60% for the gel and cream formulations, respectively. The representative dermal absorption of BCP was evaluated to be 12.20 ± 2.63% based on the results of the in vivo PK study.