• Textile Coloration and Finishing
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• v.28 no.3
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• pp.134-155
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• 2016

Perfluorinated chemicals are highly diverse and widely used. More than 160 substances are pre-registered under REACH and approximately 140 substances are in the existing chemicals list of Korea from this chemical group. Chemical structures of PFCs that are globally prohibited and still in uses are identified with OECD's classification of PFCs with an overall review on their uses in consumer products including textile products. Case examples for current domestic situation on use of PFCs as a major component of water-repelling agents in textile products as well as a brief summary of eight major PFC manufacturers' situation are presented from our survey study along the supply chains and the most recent report of EPA stewardship programme, respectively.

• Safety and Health at Work
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• v.4 no.1
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• pp.1-11
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• 2013

This review surveys the recent literature on the neurodevelopmental impacts of chemical exposures during pregnancy. The review focuses primarily on chemicals of recent concern, including phthalates, bisphenol-A, polybrominated diphenyl ethers, and perfluorinated compounds, but also addresses chemicals with longer histories of investigation, including air pollutants, lead, methylmercury, manganese, arsenic, and organophosphate pesticides. For some chemicals of more recent concern, the available literature does not yet afford strong conclusions about neurodevelopment toxicity. In such cases, points of disagreement among studies are identified and suggestions provided for approaches to resolution of the inconsistencies, including greater standardization of methods for expressing exposure and assessing outcomes.

• Environmental Analysis Health and Toxicology
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• v.25 no.2
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• pp.145-151
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• 2010

Perfluorinated chemicals (PFCs) is a kinds of persistent organic pollutants, and have the potential toxicity of which is causing great concern. In this study, we employed Oryzias latipes embryos to investigate the developmental toxicity of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA)s compound using flowthrow system for 14 day. O. latipes embryos were exposed to solvent control, 20, 40 and 80 mg/L of PFOS and 62.5, 130, 260 mg/L of PFOA respectively. After exposure, hatchability, mortality, total length and heart beats were examined. Hatching rates were reduced approximately 27% in the 80 mg/L PFOS-treated group and 17% in the 62.5, 130 mg/L PFOA-treated groups. Heart beats in the PFOS-treated groups were reduced at 7 day but, PFOA-treated groups were increased heart beats. 80 mg/L PFOS treated group showed significant reduction in growth (total length) level to 90% of control. But PFOA did not showed significant effect on growth. In the 14 days $LC_{50}$ of PFOS and PFOA was 22.74 mg/L and 173 mg/L, respectively. The overall results indicated that the early stage of O. latipes might be a reliable model for the testing of developmental toxicity to perfluorinated chemicals.

• Membrane Journal
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• v.26 no.2
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• pp.152-158
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• 2016

The Chlor-alkali (CA) membrane cell is a major electrolysis system to produce valued chemicals such as chlorine gas and sodium hydroxide. The CA membrane process has been attracted in the industries, since it has relatively low energy consumption when compared with other CA processes. The key component in CA process is perfluorinated sulfonic acid ionomer membranes, which provide ion-selectivity and barrier properties to produced gases. Unfortunately, there is limited information to determine which factors should be satisfied for CA applications. In this study, the influences of PFSA membranes on CA performances are disclosed. They include ion transport behaviors, gas evolution capability, and chemical/electrochemical resistances under CA operation conditions.

• Environmental Analysis Health and Toxicology
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• v.25 no.2
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• pp.153-159
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• 2010

Perfluorooctane sulfonic acid (PFOS) and Perfluorooctanoic acid (PFOA) are the principal chemicals known as perfluoroalkyl acids (PFAs). Despite the widespread use of these compounds, relatively little is known about their fate and effects. The purpose of this study was to determine the toxic effects of PFOS and PFOA on Daphnia magna. In the acute toxicity test, D. magna were exposed for 48 hours at concentrations of 0, 30, 45, 67.5, 101.25 and 151.88 mg/L PFOS, and 0, 100, 160, 225, 337.5 and 506.25 mg/L PFOA, respectively. In the case of chronic toxicity test, D. magna were exposed through water for 21 days at concentrations of 0, 0.375, 0.75, 1.5, 3 and 6 mg/L PFOS, and 0, 1.25, 2.5, 5, 10 and 20 mg/L PFOA, respectively. Acute toxicity was assessed on the basis of immobility, while chronic toxicity was assessed on the basis of fecundity. The acute toxicity test on PFOS and PFOA showed that the values of $EC_{50}$ were 50.90 mg/L and 253.47 mg/L, respectively. In the chronic test, fecundity was reduced significantly at 1.5 mg/L of PFOS and 10 mg/L of PFOA, respectively. These results indicated that PFOS is more toxic to zooplankton than PFOA, and both chemicals have some hazard demonstrates risk for acute or chronic toxicity to freshwater organism.

• Environmental Engineering Research
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• v.20 no.2
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• pp.127-132
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• 2015

Perfluorooctane sulfonate (PFOS) and Perfluorooctanoic acid (PFOA) are persistent environmental pollutants, extremely stable, and possibly adversely affect human health. They are widely used in many industries and consumer goods, including sunscreen products. These substances are stable chemicals made of long carbon chains, having both lipid- and water-repellent qualities. The research objectives are (1) to find the most effective method for the preparation of semi-liquid samples by comparing solid phase extraction (SPE) and centrifugation after Pressurized liquid extraction (PLE), and (2) to determine the contamination levels of PFOS and PFOA in waterproof sunscreen samples. All sunscreen samples were analyzed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Sunscreen samples were purchased from domestic and international brands sold in Thailand. Special chemical properties were considered for the selection of samples, e.g., those found in waterproof, sweat resistant, water resistant, and non-stick products. Considering the factors of physical properties, e.g., operation time, chemical consumption, and recovery percentage for selecting methods to develop, the centrifugation method using 2 mL of extracted sample with the conditions of 12,000 rpm and $5^{\circ}C$ for 1 hour after PLE was chosen. The highest concentrations of PFOS and PFOA were detected at 0.0671 ng/g and 21.0644 ng/g, respectively. Even though present concentrations are found at ng/g levels, the daily use of sunscreen products is normally several grams. Therefore, a risk assessment of PFOS and PFOA contamination in sunscreen products is an important concern, and more attention needs to be paid to the long-term effects on human health.

• Clean Technology
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• v.18 no.2
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• pp.216-220
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• 2012

The objective of the present study was to evaluate catalytic performance of a commercial catalyst (Co/$ZrO_2-Al_2O_3$) for the decomposition of perfluorinated chemicals in a pilot scale reactor containing 30 L of catalysts. At a reaction condition of GHSV $1,800h^{-1}$, $T_{95}$ of $SF_6$ was increased from 580 to $610^{\circ}C$ with increasing of $SF_6$ concentration from 1,000 to 10,000 ppm. $T_{95}$ of $SF_6$ in catalytic decomposition was much smaller than that of thermal decomposition ($1,600^{\circ}C$). The 99% conversion of $SF_6$ was maintained for 72 hours a reaction temperature of $650^{\circ}C$. In order to maintain the $SF_6$ conversion more than 99%, it is necessary to operate at a reaction condition of GHSV less than $2,000h^{-1}$. An operating temperature of $710^{\circ}C$ was required to achieve >95% destruction of the $CF_4$, which was much higher than that of catalytic decomposition of $SF_6$.