Health & Environmental Research Online (HERO)


Glycols (25265-71-8, 110-98-5, & 24800-44-0)


35 References Were Found:

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Tuning the Ionomer Distribution in the Fuel Cell Catalyst Layer with Scaling the Ionomer Aggregate Size in Dispersion

Authors: Doo, G; Lee, JH; Yuk, S; Choi, S; Lee, DH; Lee, DW; Kim, HG; Kwon, SH; Lee, SG; Kim, HT (2018) ACS Applied Materials and Interfaces 10:17835-17841. HERO ID: 4947115

[Less] With the demands for better performance of polymer electrolyte membrane fuel cells, studies on controlling . . . [More] With the demands for better performance of polymer electrolyte membrane fuel cells, studies on controlling the distribution of ionomers have recently gained interest. Here, we present a tunable ionomer distribution in the catalyst layer (CL) with dipropylene glycol (DPG) and water mixtures as the ionomer dispersion medium. Dynamic light scattering and molecular dynamics simulation demonstrate that, by increasing the DPG content in the dispersion, the size of the ionomer aggregates in the dispersion is exponentially reduced because of the higher affinity of DPG for Nafion ionomers. The ionomer distribution of the resulting CLs dictates the dimensional feature of the ionomer dispersion. Although the ionomer distribution becomes more uniform with increasing the DPG content, an optimal power performance is obtained at a DPG content of 50 wt % regardless of feed humidity because of balanced proton and mass transports. As a guide for tuning the ionomer distribution, we suggest that the ionomer aggregates in the dispersion with a size close to that of the Pt/C aggregates form a highly connected ionomer network and maintain a porosity in the catalyst/ionomer aggregate, resulting in high power performance.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Dispersion-Solvent Control of Ionomer Aggregation in a Polymer Electrolyte Membrane Fuel Cell

Authors: Lee, JH; Doo, G; Kwon, SH; Choi, S; Kim, HT; Lee, SG (2018) Scientific Reports 8:10739. HERO ID: 4947111

[Less] In this study, we examined the influence of the dispersion solvent in three dipropylene-glycol/water . . . [More] In this study, we examined the influence of the dispersion solvent in three dipropylene-glycol/water (DPG/water) mixtures, with DPG contents of 0, 50, and 100 wt%, on ionomer morphology and distribution, using dynamic light scattering (DLS) and molecular-dynamics (MD) simulation techniques. The DLS results reveal that Nafion-ionomer aggregation increases with decreasing DPG content of the solvent. Increasing the proportion of water in the solvent also led to a gradual decrease in the radius of gyration (Rg) of the Nafion ionomer due to its strong backbone hydrophobicity. Correspondingly, MD simulations predict Nafion-ionomer solvation energies of -147 ± 9 kcal/mol in water, -216 ± 21 kcal/mol in the DPG/water mixture, and -444 ± 9 kcal/mol in DPG. These results suggest that higher water contents in mixed DPG/water solvents result in increased Nafion-ionomer aggregation and the subsequent deterioration of its uniform dispersion in the solvent. Moreover, radial distribution functions (RDFs) reveal that the (-CF2CF2-) backbones of the Nafion ionomer are primarily enclosed by DPG molecules, whereas the sulfonate groups (SO3-) of its side chains mostly interact with water molecules.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Topical delivery of anthramycin I. Influence of neat solvents

Authors: Haque, T; Rahman, KM; Thurston, DE; Hadgraft, J; Lane, ME (2017) European Journal of Pharmaceutical Sciences 104:188-195. HERO ID: 4947114

[Less] Anthramycin (ANT) was the first pyrrolobenzodiazepine (PBD) molecule to be isolated, and is a potent . . . [More] Anthramycin (ANT) was the first pyrrolobenzodiazepine (PBD) molecule to be isolated, and is a potent cytotoxic agent. Although the PBD family has been investigated for use in systemic chemotherapy, their application in the management of actinic keratoses (AK) or skin cancer has not been investigated to date. In the present work, anthramycin (ANT) was selected as a model PBD compound, and the skin penetration of the molecule was investigated using conventional Franz diffusion cells. Finite dose permeation studies of ANT were performed using propylene glycol (PG), 1,3-butanediol (BD), dipropylene glycol (DiPG), Transcutol P® (TC), propylene glycol monocaprylate (PGMC), propylene glycol monolaurate (PGML) and isopropyl myristate (IPM). The skin penetration of BD, DiPG, PG and TC was also measured. Penetration of ANT through human skin was evident for TC, PG and PGML with the active appearing to "track" the permeation of the vehicle in the case of TC and PG. Deposition of ANT in skin could be correlated with skin retention of the vehicle in the case of IPM, PGMC and PGML. These preliminary findings confirm the ability of ANT to penetrate human skin and, given the potency of the molecule, suggest that further investigation is justified. Additionally, the findings emphasise the critical importance of understanding the fate of the excipient for the rational design of topical formulations.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Analysis of glycols, glycol ethers, and other volatile organic compounds present in household water-based hand pump sprays

Authors: Kawakami, T; Isama, K; Tanaka-Kagawa, T; Jinnno, H (2017) Journal of Environmental Science and Health, Part A: Toxic/Hazardous Substances and Environmental Engineering 52:1204-1210. HERO ID: 4168926

[Less] The aim of this investigation is to clarify the types and concentrations of VOCs present in various . . . [More] The aim of this investigation is to clarify the types and concentrations of VOCs present in various commercial household water-based hand pump spray products used in Japan, and to estimate their average concentrations in indoor air when the spray product is used. We selected glycol and glycol ethers as the main target compounds, as these chemicals were detected at high frequencies and concentrations in a national survey of Japanese indoor air pollution. The extraction of these chemicals using graphite carbon cartridges was examined, with good recoveries and reproducibilities being obtained. Eighteen chemicals were analyzed in 54 commercial products and 8 chemicals were detected. More specifically, dipropylene glycol (DPG) was present in 44 samples (1.1 × 101-1.8 × 104 μg/mL); propylene glycol (PG) was present in 22 samples (1.5 × 101-2.9 × 104 μg/mL); diethylene glycol monoethyl ether (DGMEE) was found in 15 samples (trace amount-1.9 × 103 μg/mL); diethylene glycol (DEG) was present in 9 samples (1.0 × 101-2.4 × 103 μg/mL); 1,3-butandiol (13BG) was found in 5 samples (trace amount-7.4 × 103 μg/mL); 2-ethyl-1-hexanol (2E1H) was detected in 5 samples (3.2 × 10-1-4.4 × 101 μg/mL); diethylene glycol monobutyl ether (DGMBE) was present in 4 samples (2.1 × 101-7.1 × 101 μg/mL); and 3-methoxy-3-methylbutanol (MMB) was found in 2 samples (2.4 × 101-4.7 × 102 μg/mL). In addition, the average concentrations of these chemicals in indoor air were estimated using their maximum concentrations observed in the spray product. The estimated average concentrations of the chemicals in indoor air were determined to range between 1.0 × 10-2 and 1.0 mg/m3, with the exception of 2E1H and DGMBE. Furthermore, the estimated average concentrations of PG, 13BG, and DGMEE in indoor air were comparable to or higher than those reported in a national survey of Japanese indoor air pollution. It therefore appeared that household water-based hand pump sprays may contribute to the presence of these chemicals in indoor air. In contrast, estimated average concentrations of 2E1H in indoor air were low, its concentrations observed in a national survey of Japanese indoor air pollution are likely due to the use of plasticizers and paints.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

754 exposures to reed diffusers reported to the United Kingdom National Poisons Information Service 2010-2014

Authors: Panchal, B; Eddleston, M; Thomas, SH; Thompson, JP; Vale, JA (2016) Clinical Toxicology 54:333-338. HERO ID: 3114932

[Less] OBJECTIVE: The objective of this study is to review the reported toxicity of reed diffuser . . . [More] OBJECTIVE: The objective of this study is to review the reported toxicity of reed diffuser fragrance liquid which, in addition to essential oils, commonly contains glycol ethers but other ingredients and/or alternatives are 3-methoxy-3-methyl-1-butanol, petroleum distillates, ethanol and isopropanol.

METHODS: We analysed retrospectively enquiries to the United Kingdom National Poisons Information Service between 1 January 2010 and 31 December 2014.

RESULTS: 754 patients were exposed to reed diffusers; the majority (n = 712) were children < 5 years. Ingestion was the most common route of exposure (706 of 754 patients) and involved the liquid alone (n = 570), water beads alone (n = 84), sucking on the reeds (n = 31) or ingesting the liquid and water beads (n = 21). The reported amount of fragrance liquid ingested was known in only 76 of 591 cases (12.9%), with a median (IQR) volume of 20.0 (IQR = 10-40) mL. The WHO/IPCS/EC/EAPCCT Poisoning Severity Score (PSS) was known in 702 of 706 sole ingestions: in 574 (81.3%), the PSS was 0 (asymptomatic); in 117 (16.6%) patients, the PSS was 1 (minor toxicity); in 11 (1.6%), the PSS was 2 (moderate toxicity); there were no patients with features graded PSS 3 (severe toxicity). Significantly (p = 0.008) more patients became symptomatic (PSS 1 and PSS 2) following the ingestion of a reed diffuser containing 3-methoxy-3-methyl-1-butanol than propylene glycol monobutyl ether, though there was no significant difference when compared with those containing dipropylene glycol monomethyl ether (p = 0.181). The most common features following ingestion of fragrance liquid were nausea and vomiting (n = 53), coughing (n = 17) and CNS depression (n = 9). Seven patients suffered eye exposure alone: two developed eye pain and four conjunctivitis. Dermal exposure alone was reported in six patients, two of whom developed skin irritation.

CONCLUSIONS: The majority of patients in our study developed no features or only minor symptoms following ingestion of reed diffuser fragrance liquid.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

One-pot preparation of a novel monolith for high performance liquid chromatography applications

Authors: Jiao, X; Shen, S; Shi, T (2015) Journal of Chromatography B, Analytical Technologies in the Biomedical and Life Sciences 1007:100-109. HERO ID: 4276472

[Less] Various novel porous organic-based monoliths with the mode of hydrophobicity were synthesized by in . . . [More] Various novel porous organic-based monoliths with the mode of hydrophobicity were synthesized by in situ free-radical crosslinking copolymerization and optimized for the separations of small molecules and high-performance reversed-phase chromatography (RP-chromatography). These monoliths contained co-polymers based on glycidyl methacrylate (GMA)/ethylene glycol dimethacrylate (EDMA)/tripropylene glycol diacrylate (TPGDA) or EDMA/TPGDA. A mixture of cetanol, methanol and poly (ethylene glycol) (PEG) was used as the porogen, with the ratio of these solvents being varied along with the polymerization temperature to generate a library of monoliths. The conditions were optimized and the resulting poly (GMA-co-TPGDA-co-EDMA) monolith was investigated by infrared spectrometer (IR), field emission scanning electron microscope (FESEM), and mercury intrusion porosimetry (MIP), respectively. The column performance was assessed by the separation of a series of neutral solutes of benzene derivatives. The result demonstrated that the prepared monolith exhibited an RP-chromatographic behavior and relatively homogeneous structure, good permeability and separation performance. Moreover, the relative standard deviations (RSDs) of the retention factor values for benzene derivatives were less than 1.5% (n=7, column-to-column). The approach used in this study was extended to the separation of anilines.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

The challenge of using read-across within the EU REACH regulatory framework; how much uncertainty is too much? Dipropylene glycol methyl ether acetate, an exemplary case study

Authors: Ball, N; Bartels, M; Budinsky, R; Klapacz, J; Hays, S; Kirman, C; Patlewicz, G (2014) Regulatory Toxicology and Pharmacology 68:212-221. HERO ID: 4946621

[Less] The use of read-across of data within a group of structurally similar substances potentially allows . . . [More] The use of read-across of data within a group of structurally similar substances potentially allows one to characterise the hazards of a substance without resorting to additional animal studies. However the use of read-across is not without challenges, particularly when used to address the needs of a regulatory programme such as the EU REACH regulation. This paper presents a case study where a previously accepted read-across approach was used to address several data gaps in a REACH registration dossier but was subsequently rejected in part by the European Chemicals Agency (ECHA), resulting in the requirement to perform a developmental toxicity study in rodents. Using this case study, this paper illustrates some of the practical challenges faced when making use of read-across, particularly with respect to addressing the uncertainty associated with the use of read-across; showcasing the scientific justification and highlighting some of the potential implications/opportunities for future cases.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Identification of toxicants in cinnamon-flavored electronic cigarette refill fluids

Authors: Behar, RZ; Davis, B; Wang, Y; Bahl, V; Lin, S; Talbot, P (2014) Toxicology In Vitro 28:198-208. HERO ID: 4088550

[Less] In a prior study on electronic cigarette (EC) refill fluids, Cinnamon Ceylon was the most cytotoxic . . . [More] In a prior study on electronic cigarette (EC) refill fluids, Cinnamon Ceylon was the most cytotoxic of 36 products tested. The purpose of the current study was to determine if high cytotoxicity is a general feature of cinnamon-flavored EC refill fluids and to identify the toxicant(s) in Cinnamon Ceylon. Eight cinnamon-flavored refill fluids, which were screened using the MTT assay, varied in their cytotoxicity with most being cytotoxic. Human embryonic stem cells were generally more sensitive than human adult pulmonary fibroblasts. Most products were highly volatile and produced vapors that impaired survival of cells in adjacent wells. Cinnamaldehyde (CAD), 2-methoxycinnamaldehyde (2MOCA), dipropylene glycol, and vanillin were identified in the cinnamon-flavored refill fluids using gas chromatography–mass spectrometry and high-pressure liquid chromatography (HPLC). When authentic standards of each chemical were tested using the MTT assay, only CAD and 2MOCA were highly cytotoxic. The amount of each chemical in the refill fluids was quantified using HPLC, and cytotoxicity correlated with the amount of CAD/product. Duplicate bottles of the same product were similar, but varied in their concentrations of 2MOCA. These data show that the cinnamon flavorings in refill fluids are linked to cytotoxicity, which could adversely affect EC users.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

A toxicological review of the propylene glycols

Authors: Fowles, JR; Banton, MI; Pottenger, LH (2013) Critical Reviews in Toxicology 43:363-390. HERO ID: 3038211

[Less] The toxicological profiles of monopropylene glycol (MPG), dipropylene glycol (DPG), tripropylene glycol . . . [More] The toxicological profiles of monopropylene glycol (MPG), dipropylene glycol (DPG), tripropylene glycol (TPG) and polypropylene glycols (PPG; including tetra-rich oligomers) are collectively reviewed, and assessed considering regulatory toxicology endpoints. The review confirms a rich data set for these compounds, covering all of the major toxicological endpoints of interest. The metabolism of these compounds share common pathways, and a consistent profile of toxicity is observed. The common metabolism provides scientific justification for adopting a read-across approach to describing expected hazard potential from data gaps that may exist for specific oligomers. None of the glycols reviewed presented evidence of carcinogenic, mutagenic or reproductive/developmental toxicity potential to humans. The pathologies reported in some animal studies either occurred at doses that exceeded experimental guidelines, or involved mechanisms that are likely irrelevant to human physiology and therefore are not pertinent to the exposures experienced by consumers or workers. At very high chronic doses, MPG causes a transient, slight decrease in hemoglobin in dogs and at somewhat lower doses causes Heinz bodies to form in cats in the absence of any clinical signs of anemia. Some evidence for rare, idiosyncratic skin reactions exists for MPG. However, the larger data set indicates that these compounds have low sensitization potential in animal studies, and therefore are unlikely to represent human allergens. The existing safety evaluations of the FDA, USEPA, NTP and ATSDR for these compounds are consistent and point to the conclusion that the propylene glycols present a very low risk to human health.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Time-weighted average sampling of airborne propylene glycol ethers by a solid-phase microextraction device

Authors: Shih, HC; Tsai, SW; Kuo, CH (2012) Journal of Occupational and Environmental Hygiene 9:427-436. HERO ID: 2563138

[Less] A solid-phase microextraction (SPME) device was used as a diffusive sampler for airborne propylene glycol . . . [More] A solid-phase microextraction (SPME) device was used as a diffusive sampler for airborne propylene glycol ethers (PGEs), including propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), and dipropylene glycol monomethyl ether (DPGME). Carboxen-polydimethylsiloxane (CAR/PDMS) SPME fiber was selected for this study. A polytetrafluoroethylene (PTFE) tubing was used as the holder, and the SPME fiber assembly was inserted into the tubing as a diffusive sampler. The diffusion path length and area of the sampler were 0.3 cm and 0.00086 cm(2), respectively. The theoretical sampling constants at 30°C and 1 atm for PGME, PGMEA, and DPGME were 1.50 × 10(-2), 1.23 × 10(-2) and 1.14 × 10(-2) cm(3) min(-1), respectively. For evaluations, known concentrations of PGEs around the threshold limit values/time-weighted average with specific relative humidities (10% and 80%) were generated both by the air bag method and the dynamic generation system, while 15, 30, 60, 120, and 240 min were selected as the time periods for vapor exposures. Comparisons of the SPME diffusive sampling method to Occupational Safety and Health Administration (OSHA) organic Method 99 were performed side-by-side in an exposure chamber at 30°C for PGME. A gas chromatography/flame ionization detector (GC/FID) was used for sample analysis. The experimental sampling constants of the sampler at 30°C were (6.93 ± 0.12) × 10(-1), (4.72 ± 0.03) × 10(-1), and (3.29 ± 0.20) × 10(-1) cm(3) min(-1) for PGME, PGMEA, and DPGME, respectively. The adsorption of chemicals on the stainless steel needle of the SPME fiber was suspected to be one of the reasons why significant differences between theoretical and experimental sampling rates were observed. Correlations between the results for PGME from both SPME device and OSHA organic Method 99 were linear (r = 0.9984) and consistent (slope = 0.97 ± 0.03). Face velocity (0-0.18 m/s) also proved to have no effects on the sampler. However, the effects of temperature and humidity have been observed. Therefore, adjustments of experimental sampling constants at different environmental conditions will be necessary.