Tiered human health risk assessment of antibacterial quaternary ammonium compounds (QACs) in dishwashing detergents.

Quaternary ammonium compounds (QACs) are widely used in consumer products because of their unique antibacterial properties, and dishwashing detergents are a major source of exposure through oral, inhalation, and dermal routes. The three classes of QACs, including benzalkonium chloride (BAC), n-alkyldimethylethylbenzylammonium chloride (ADEBAC), and di-n-alkyldimethylammonium chloride (DDAC), in spray and non-spray types of dishwashing detergents were quantified by high-performance liquid chromatography-mass spectrometry. A tiered risk assessment approach was also considered. In the Tier 1 assessment, the mean and worst-case exposure were estimated to screen for rough exposure and risk levels. In the Tier 2 assessment, mean and upper-tail exposure levels were calculated based on the exposure parameters of Korean consumers using Monte Carlo simulation. QACs had a low frequency of detection of up to 20% in dishwashing detergents, and the contents of detected QACs varied depending on the individual samples. Based on the results of the Tier 1 assessment, BACs and DDACs posed potential health risks via inhalation and dermal routes. Tier 2 assessment suggested that the current level of oral and dermal exposure of Korean consumers to QACs in dishwashing detergents is unlikely to pose a health risk, even for upper-tail exposure groups. However, the present results suggest that spray-type DDACs may pose a health risk in the upper-tail inhalation exposure group, and further investigation is required to clarify this risk.

Evaluation of Skin Irritation of Acids Commonly Used in Cleaners in 3D-Reconstructed Human Epidermis Model, KeraSkinTM.

Cleaners such as dishwashing liquids contain various chemicals that cause skin damage. Alkaline agents used in cleaners alter the lipid composition of the skin and damage the skin barrier. However, little is known about the effects of acids used in cleaners on the skin. Here, we investigated the effects of acidic pH on the skin and evaluated the skin irritation of acids commonly used in cleaners with a 3D-reconstructed human epidermis model, KeraSkinTM, according to OECD TG439. First, to examine the effects of acidic pH, we evaluated the skin irritation of citrate buffers (0.1 M, McIlvaine buffer) prepared in a wide pH range (pH 1.5-6.0). Surprisingly, cell viability was not significantly affected even at pH 1.5, reflecting that the acidity alone may not be sufficient to induce skin irritation. Even after longer exposure (180 min), the cell viability was not reduced below 50%, a cutoff to determine an irritant. To examine the effect of the anionic part, several organic acids used in cleaners (citric acid, glycolic acid, lactic acid, malic acid, and succinic acid) were examined. These organic acids also failed to reduce viability at 0.1 M. However, at 1 M, most of the acids tested, except lactic acid, were determined to be skin irritants. Histology further supported the skin irritancy of acids at 1 M. Similarly, inorganic acids (hydrogen bromide, hydrogen chloride, nitric acid, and sulfuric acid) were determined to be irritants only at 1 M. In the case of alkaline agents, pH and concentrations were also important factors to determine the skin irritancy, although the epidermal structure and lipids were more damaged than acids. Collectively, we demonstrated that both the pH and concentration are important factors for the skin irritancy of acids, shedding an important insight into the mechanism of skin irritation.

Probabilistic risk assessment of preservatives in dishwashing detergents and wet wipes for Korean consumers.

Preservatives are essential additives in dishwashing detergents and wet wipes. Ensuring the safe use of preservatives in products is important for public health, as some preservatives are associated with health issues. In this study, the content of 12 preservatives in 105 dishwashing detergents and 105 wet wipes was determined, where these compounds are commonly found, among consumer products. A realistic exposure estimation was considered by using Korean consumer-specific exposure parameters for adults and babies. A probabilistic risk assessment was conducted by applying the Monte Carlo simulation method. Benzoic acid (41%) and cetylpyridinium chloride (30%) were the most commonly used preservatives in dishwashing detergents and wet wipes, respectively, although their content in different products (benzoic acid: 0.28-19.4 mg/g in dishwashing detergents; cetylpyridinium chloride: 0.003-0.64 mg/g in wet wipes) varied widely. The calculated median and upper-limit margin of safety (MOS) values related to systemic health effects and skin sensitization from exposure to preservatives largely exceeded the target MOS, which confirmed the safety of the products. Exposure to preservatives from wet wipes was several times higher in babies than in adults. Sensitivity analysis revealed that the amount of the product used, frequency of use, and weight fraction of the preservative were the major contributors to the exposure to preservatives from dishwashing detergents and wet wipes.