Evaluating Phthalate Contaminant Migration Using Thermal Desorption⁻Gas Chromatography⁻Mass Spectrometry (TD⁻GC⁻MS)

Phthalate esters in clothing: A review

Phthalate esters (PAEs) are widely used as plasticizers to enhance the flexibility and durability of different consumer products, including clothing. However, concerns have been raised about the potential adverse health effects associated with the presence of phthalates in textiles, such as endocrine disruption, reproductive toxicity and potential carcinogenicity. Based on examination of more than 120 published articles, this paper presents a comprehensive review of studies concerning the phthalate content in clothing and other textile products, with special emphasis on those conducted in the last decade (2014-2023). The types and role of PAEs as plasticizers, the relevant legislation in different countries (emphasizing the importance of monitoring PAE levels in clothing to protect consumer health) and the analytical methods used for PAE determination are critically evaluated. The review also discusses the models used to evaluate exposure to PAEs and the associated health risks. Finally, the study limitations and challenges related to determining the phthalate contents of textile products are considered.

Simultaneous screening of 33 restricted substances in polymer materials using pyrolysis/thermal desorption gas chromatography-mass spectrometry

The purpose of this study was to offer a quick and efficient method to screen for multiple restricted additives in polymer materials. A solvent-free pyrolysis gas chromatography-mass spectrometry method was developed to simultaneously screen 33 restricted substances, comprising 7 phthalates, 15 bromine flame retardants, 4 phosphorus flame retardants, 4 ultraviolet stabilizers, and 3 bisphenols. The pyrolysis technique and temperatures affecting additive desorption were studied. Under optimized conditions, the instrument sensitivity was confirmed using in-house reference materials at concentrations of 100 mg/kg and 300 mg/kg. The linear range was between 100 and 1000 mg/kg in 26 compounds, and in the other compounds it was between 300 and 1000 mg/kg. In this study, in-house reference materials, certified reference materials, and proficiency testing samples were used for method verification. The relative standard deviation of this method was less than 15%, and recoveries ranged from 75.9 to 107.1% for most of the compounds, with a few exceeding 120%. Furthermore, the screening method was verified with 20 plastic products used in daily life and 170 recycled plastic particle samples from imports. The experimental results showed that phthalates were the main additives in plastic products, and among 170 recycled plastic particle samples, 14 samples were found to contain restricted additives. The main additives in recycled plastics were bis(2-ethylhexyl) phthalate, di-iso-nonyl phthalate, hexabromocyclododecane, and 2,2',3,3',4,4',5,5',6,6'-decabromodiphenyl ether at concentrations between 374 and 34785 mg/kg, except for some results that exceeded the maximum measured value of the instrument. Compared with traditional methods, an important advantage is that this method simultaneously tests for 33 additives without sample pretreatment, covering a variety of additives limited by laws and regulations, and therefore can provide more comprehensive and thorough inspections.

Enhanced migration of plasticizers from polyvinyl chloride consumer products through artificial sebum

In the present study, the migration of plasticizers from modeled and commercial polyvinyl chloride (mPVC and cPVC, respectively) to poly(dimethylsiloxane) via artificial sebum was assessed to mimic the dermal migration of plasticizers. In addition, the various factors affecting migration of phthalic acid esters (PAEs) from diverse PVC products were investigated. The migrated mass and migration ratio of PAEs increased but the migration rate decreased over time. The migration rate increased with sebum mass, contact time, and temperature but decreased under higher pressure. Low-molecular-weight PAEs (dimethyl phthalate and diethyl phthalate) migrated in higher amounts than high-molecular-weight PAEs (dicyclohexyl phthalate [DCHP] and diisononyl phthalate [DINP]). Diffusion of all PAEs in mPVC increased with temperature, with diffusion coefficients ranging from 10^-13 to 10^-15, 10^-12 to 10^-14, and 10^-10 to 10^-12 cm²·s^-1 at 25 °C, 40 °C, and 60 °C, respectively; the enthalpy of activation ranged between 127 and 194 kJ·mol^-1. Moreover, migration depended on total PAE content of the product, as the diffusion coefficient for DINP in cPVC (softer PVC) was approximately three orders of magnitude higher than that for DINP in mPVC (harder PVC); this may be due to the increase in free volume with increasing plasticizer content. Finally, the daily exposure doses of the plasticizers were estimated. These findings will be helpful for estimating dermal exposure risk.

Phthalate migration and its effects on poly(vinyl chloride)-based footwear: pathways, influence of environmental conditions, and the possibility of human exposure

The study of phthalate migration in footwear is important from an environmental viewpoint and the consumer health perspective as it remains in direct contact with the user for a long time. In this research article, the migration of phthalate, specifically di-(2-ethylhexyl) phthalate (DEHP), from the poly(vinyl chloride) (PVC) shoe sole to the attached leather insole has been studied for six months under different environmental conditions. After one month, the DEHP concentration in the PVC sole decreased by 45-58%, and that in the leather insole increased from 0.35 mg g^-1 to 38-58 mg g^-1. After six months, about 90% of the DEHP has been lost from the PVC sole, and that in the leather insole reached close to its initial value (value before the experiment). The migration rate depends on the environmental conditions and the presence of phthalate soluble solvents in the sole-adhesive-insole system of the footwear. The influence of DEHP migration on the physicochemical characteristics of the PVC sole and leather insole has been studied by Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR), thermo-gravimetric analysis (TGA), and differential scanning calorimetry (DSC). The migration and emission pathways of DEHP, the influence of environmental conditions, and the possibility of human exposure to phthalate through footwear are discussed.

Transfer of Frictional Contact Derived Phthalates from Pad Surface Enhances Dermal Exposure

Dermal exposure to chemicals derived from object surface contact is an important contributor to increased health risk. However, chemical transfer induced by mechanical friction between dermal and object surface has yet to be adequately addressed. To fill this knowledge gap, rubbing fabrics were used as surrogate skins to stimulate dermal mechanical friction with pad products with phthalates as target analytes. The results showed that the amounts of phthalates transferred increased linearly with contact burden (50-1000 g), contact duration (1-10 min), and sliding speed (3.0-9.0 cm s^-1). The surface texture of surrogate skins dictated the accumulation of phthalates. Net/pocket micro-surface structures of rubbing fabrics induced a higher accumulation of phthalates than U-shape structures of fabrics with a similar surface roughness. Covering of the pad surface by a layer of textile was effective in minimizing the transfer of phthalates induced by mechanical motion. The estimated transfer efficiency of bis(2-ethylhexyl) ester (DEHP) derived from rubbing friction (0.005-0.05%) upon the pad surface over 8 h was greater than those for gas-phase emission (0.00002-0.0005% over 24 h) and sweat transfer (0.008-0.012% over 24 h). These results indicated that dermal frictional contact with the surface of pad products was an important exposure pathway.

Guidance in selecting analytical techniques for identification and quantification of non-intentionally added substances (NIAS) in food contact materials (FCMS)

There are numerous approaches and methodologies for assessing the identity and quantities of non-intentionally added substances (NIAS) in food contact materials (FCMs). They can give different results and it can be difficult to make meaningful comparisons. The initial approach was to attempt to prepare a prescriptive methodology but as this proved impossible; this paper develops guidelines that need to be taken into consideration when assessing NIAS. Different approaches to analysing NIAS in FCMs are reviewed and compared. The approaches for preparing the sample for analysis, recommended procedures for screening, identification, and quantification of NIAS as well as the reporting requirements are outlined. Different analytical equipment and procedures are compared. Limitations of today's capabilities are raised along with some research needs.

Study on the Oxidation Products of Hemp Seed Oil and its Application in Cosmetics

Hemp seed oil has a very better effect of sunscreen, repair, anti-allergy and anti-aging, as a result of which it is a high-quality raw material for skin care products. In this study, the oxidation degree of hot-pressed and cold-pressed hemp seed oil which was stored in five different environments, was evaluated. The results showed that the long-chain unsaturated fatty acids were oxidized. The oxidation products of hemp seed oil were analyzed by headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC/MS) and high performance liquid chromatography (HPLC). All hemp seed oils which were stored at low-temperature protected from light and outdoor environment contained aldehydes, ketones, and alcohols, which have a negative impact on the health of consumers. Furthermore, hemp seed emulsion was prepared with different HLB values. After the 2nd month, hemp seed oil emulsion exhibited a good stability without stratification.

Migration regularity of phthalates in polyethylene wrap film of food packaging

As a kind of polymer material additive, phthalic acid esters (PAEs) are widely used in food industry. However, PAEs are environmental endocrine disruptors with reproductive toxicity and teratogenic carcinogenicity, which are difficult to be degraded in the natural environment. In this paper, gas chromatography-mass spectrometer (GC-MS) methods for PAEs in polyethylene wrap film were optimized. For diisobutyl phthalate (DIBP) and dibutyl phthalate (DBP) that were mainly detected, the method had a good linearity in 1 to 500 ng/g. Then, we confirmed that the migration of DIBP and DBP from polyethylene wrap film increased with time and temperature. It is found that the migration law in different food simulations well followed the migration dynamics first-level model. The rate constant K₁ and initial release rate V₀ are inversely proportional to the polarity of the simulated liquid. We hope that this study can serve as a valuable reference for further research on the migration of food packing materials. PRACTICAL APPLICATION: In this paper, we present a simple example of applying migration model to evaluate the migration behaviors of PAEs in food packaging materials along with their hazardous properties. It can serve as a valuable reference for further research on the migration of food packing materials.