Chlorinated Hydrocarbon Solvents Research Articles

Monitoring of occupational exposure to dichloromethane by diffuse vapor sampling and urinalysis.

The aim of the present study was to develop valid methods for monitoring of occupational exposure to dichloromethane (DCM). Carbon cloth as an adsorbent in diffusive sampling was tested for its capacity to adsorb DCM vapor and to retain adsorbed DCM after termination of the exposure. Urine samples collected from DCM-exposed workers were analyzed for DCM by the head-space technique. After extraction with carbon disulfide, DCM in the cloth was analyzed on a DB-WAX capillary column by flame-ionization detection gas chromatography (FID-GC) and DCM in urine was analyzed by electron-capture detection (ECD)-GC. The diffusive sampling with carbon cloth as an adsorbent is applicable to 4-h monitoring of exposure to up to 100 ppm DCM vapor. DCM concentrations detected in end-of-shift urine samples correlated linearly with time-weighted average DCM concentrations measured in the breathing-zone air of the exposed workers; essentially the same exposure-excretion relationship was obtained by vapor monitoring for the afternoon 4-h period as compared with a whole day (8-h) of vapor monitoring. There was no sex difference in the exposure-excretion relation. Both personal diffusive sampling (at up to 100 ppm DCM and for up to 4 h) and biological exposure monitoring by urinalysis for DCM are applicable in occupational health as reliable measures of exposure to this chlorinated hydrocarbon solvent.

The Dual Pumping Technique (DPT) for level-determined sampling in fully screened groundwater wells

A new and inexpensive technique to obtain vertical hydrochemical profiles in aquifers is presented. The Dual Pumping Technique (DPT) is designed for use in fully-screened groundwater wells and represents an alternative to packer installations or similar sampling devices. Two pumps are placed at either end of the well screen. The ratio of their pumping rates is varied from 1 to 0. Depending on this ratio, the two pumps abstract variable portions of the influx distribution. A water divide develops in the well, separating the flow upward from the flow downward. A set of samples from the upper and lower pump are taken for different pumping rate ratios. Measured solute concentrations in these samples, together with the influx distribution determined by flow logging, are used to reconstruct vertical concentration profiles. The measured data are evaluated with a simple, robust algorithm, which is derived in the text and exemplified in the Appendix. The DPT was used to determine vertical concentration distributions of chlorinated hydrocarbon solvents (CHS) and tritium in a contaminated aquifer near Heidelberg, Germany. Comparison of the concentration profile obtained with the DPT with CHS and tritium data from a 50-m distant multilevel well showed the principal applicability of the new technique. The pattern of the vertical concentration distributions was successfully identified with the DPT, but the absolute CHS concentration values were one order of magnitude higher in the multilevel well, due to the fact that the multilevel well is probably closer to the centre of the plume than the well used for the DPT. The 3H values could be compared directly and showed an excellent agreement. Further evaluation of the DPT in a situation where a multilevel reference well is in closer vicinity to the test well is planned.

Foreseeability of environmental hazards: the implications of the Cambridge Water Company case

Abstract The House of Lords decision, in the case of Cambridge Water Company v. Eastern Counties Leather and Others , introduced the concept of foreseeability as one test of civil liability for environmental pollution. In this paper the main criteria for foreseeability of pollution hazards are considered, including: • recognition of the acute and chronic toxicity of a potential pollutant; • availability of suitable detection and analysis methods; • understanding of migration and transport mechanisms in the environment. Examples of the application of foreseeability criteria are discussed, such as chlorinated hydrocarbon solvents (as in the Cambridge Water Company case), methyl tertiary butyl ether and mine drainage waters.

Types of organic solvents used in workplaces and work environment conditions with special references to reproducibility of work environment classification.

A survey of solvent was conducted for 196 unit work areas in 95 plants in 1994 to 1996 in Hiroshima Prefecture, Japan. The survey had been repeated every 6 months (i.e., twice a year) during the 3-year period. Sampling and analysis of the solvent vapors were carried out after national protocols set by the regulation. Toluene was most frequently detected regardless of the type of solvent work (except for degreasing), whereas the second- and the third-most common solvents varied depending on the type of solvent works. Among chlorinated hydrocarbon solvents for degreasing, dichloromethane was most widely used. Solvent concentrations were generally low as none of the median concentrations exceeded corresponding Administrative Control Levels set by the regulation, either individually or even when the assumption of additiveness was applied. Among the 1176 cases analyzed, 80% of the unit work areas were evaluated as adequate (i.e., classified as Class I). Furthermore, about 57% stayed in Class I throughout the 3 years, suggesting that solvent exposure conditions were generally quite stable. In regulatory evaluation by classification, A-sampling was decisive in most cases, whereas the role of B-sampling was limited.

Self-association of cholesterol in some chlorinated hydrocarbon solvents

The self-association of cholesterol in dilute solutions in 1,2-dichloroethane, trichloromethane and tetrachlorormethane and over the temperature range 298–328 K was investigated using conventional infrared spectroscopy. The information on the size of the predominant cholesterol species was obtained by numerical processing of the solution spectra, recorded in the fundamental OH stretching range. Formation constants were derived from monomer absorbances measured as a function of cholesterol concentration. The following prevailing species and their enthalpies of formation were established: the monomer A 1 and monomer-solvent complex A 1* (Δ H 1*=−9±3 kJ mol −1) in 1,2-dichloroethane; the monomer and open dimer ( Ã 2) (Δ H̃ 2=−15.0±1.2 kJ mol −1) in trichloromethane; the monomer, open trimer ( Ã 3) (Δ H̃ 3=−31±3 kJ mol −1) and cyclic hexamer ( Â 6) (Δ Ĥ 6=−70±10 kJ mol −1) in tetrachloromethane.

Preparation and properties of flame-retardant polyphosphate esters: Low-temperature solution polycondensation of 3,3,?5,5?-tetrabromobisphenol AF and aryl phosphorodichloridates

This article describes the syntheses of aromatic polyphosphates from the reaction of various aryl phosphorodichloridates with 3,3',5,5'-tetrabromobisphenol AF (TBPAF) in a chlorinated hydrocarbon solvent under low-temperature conditions. The new polyphosphates obtained were characterized by infrared, 13 C and 31 P NMR spectra, elemental analysis, inherent viscosity, TGA, DSC, X-ray diffraction, limiting oxygen index, contact angle, and molar mass measurement. All of the polyphosphates obtained had high yields, and the inherent viscosities were in the range 0.12-0.15 dL g -1 . All of the polymers start degrading between 210 and 267°C and had 14-26% residual mass at 700°C in nitrogen. Polymer E, having a methoxy group in the side chain phenyl ring, showed better thermal stability than the other polymers. The X-ray diffraction patterns revealed that all of the polyphosphates were amorphous. These polyphosphates had glass transition temperatures between 140 and 154°C. Polymers obtained from TBPAF had excellent flame retardency, as indicated by high limiting oxygen index values in the range of 63-68. The water contact angles (θ w ) of all of the polyphosphates were in the range of 74-87°. The contact angles of polymers A and B were larger than those of other polyphosphates that contain more oxygen (polymers C and E) or bromine atoms (polymer D).

Synthesis of sulfone-containing polyphosphates: low temperature solution polycondensation of bisphenol S analogues and aryl phosphorodichlorides

This paper describes the synthesis of new sulfone-containing polyphosphates from the reaction of various aryl phosphorodichlorides with bisphenol S (BPS) and its analogues in a chlorinated hydrocarbon solvent under low temperature conditions. The polyphosphates obtained were characterized by IR, 13C and 31P NMR spectra, elemental analysis, inherent viscosity, TGA, DSC, X-ray diffraction, solubility, LOI, contact angle and molar mass measurement. All the polyphosphates had high yields and the inherent viscosities were in the range of 0.12–0.44 dl g −1. Almost all the polyphosphates, except that obtained from the bis[4-(β-hydroxyethoxy)-phenyl] sulfone (HEPS) were stable up to 220 °C, exhibited 10% loss of mass at 313–424 °C, and had 39–62% residual mass at 700 °C in nitrogen. The polyphosphates derived from TMBS had glass transition temperatures between 128 and 173 °C which were about 60 °C higher than that of the polyphosphate obtained from BPS. The X-ray diffraction patterns revealed that almost all the polyphosphates were semicrystalline and the polymers containing the flexible ether linkage (polymer Ie, IIe and IIIe) had a relatively large degree of crystallinity. The polyphosphates obtained from BPS had good flame retardancy and showed higher LOI values, as indicated by high limiting oxygen index values in the range of 30–65. The water contact angles of the polyphosphates derived from TMBS were larger than those of other polymers which have a higher oxygen content.

Changes in plasma lipoproteins as toxicity markers for carbon tetrachloride, chloroform, and dichloromethane.

Effects of single intraperitoneal (i.p.) administration of carbon tetrachloride (CCl4), chloroform (CHCl3), and dichloromethane (CH2Cl2) on lipoproteins in plasma and liver were investigated in rats. Changes in lipoproteins caused by these solvents were compared with changes in traditional hepatotoxicity markers such as GPT (ALT). Following the administration, concentrations of lipoproteins (VLDL, LDL, HDL), triglyceride, cholesterol, and GPT activity in plasma were determined through changes in liver weight, liver content of triglyceride, malon dialdehyde (MDA), and glutathione (GSH). Time-course study revealed that changes in plasma and liver reached their peaks at 19 or 32 hr following the administration of CCl4 or CHCl3. Peaks of changes were observed at 8 or 19 hr following the administration of CH2Cl2. Dose dependency of these changes was investigated at dosages of 3, 30, and 300 mg/kg of CCl4 or CHCl3, and 300, and 1,000 mg/kg of CH2Cl2. Significant decreases in triglyceride and apolipoproteins in VLDL fraction were observed at 3 mg/kg of CCl4. Such VLDL components decreased at 30 mg/kg of CHCl3. HDL decreased significantly at 300 mg/kg of CH2Cl2 and marked increase in LDL occurred at 1,000 mg/kg of the solvent. Liver weight and liver content of triglyceride and MDA significantly increased at 30 mg/kg of CCl4, while significant increase in GPT activity was observed at 300 mg/kg of CCl4 and CHCl3. GPT increased significantly at 1,000 mg/kg of CH2Cl2. These results revealed that changes in plasma lipoproteins can serve as sensitive and simple markers for liver disorders caused by chlorinated hydrocarbon solvents such as CCl4, CHCl3, or CH2Cl2.

Chlorinated hydrocarbon solvents and cancer

Chlorinated hydrocarbon solvents and cancer

Chlorinated hydrocarbon solvents and biliary‐pancreatic cancer: Report of three cases

Chlorinated hydrocarbon solvents and biliary‐pancreatic cancer: Report of three cases

Synthesis of fluorine-containing polyphosphates: low-temperature solution polycondensation of bisphenol AF and aryl phosphorodichloridates

This paper describes the synthesis of aromatic polyphosphates from the reaction of various aryl phosphorodichloridates with bisphenol AF in a chlorinated hydrocarbon solvent under low-temperature conditions. The polyphosphates obtained were characterized by IR, 133C- and 31P-NMR spectra, elemental analysis, inherent viscosity, TGA, DSC, X-ray diffraction, LOI, contact angle and molar mass measurement. All the polyphosphates obtained had high yields and the inherent viscosities were in the range 0.25–0.31 dl g −1. The weight average molar masses ( M w ) were in the range 0.96 × 10 4−1.33 × 10 4 with relatively narrow molar mass distributions ( M w / M n = 1.2−1.4 ). All the polymers, except polymer C, are stable up to 250°C, exhibited 10% loss of mass at 417–463°C, and had 20–30% residual mass at 700°C in nitrogen. The X-ray diffraction patterns revealed that all the polyphosphates are semicrystalline and polymer E, containing a flexible ether linkage, has a relatively large degree of crystallinity. The fluorine-containing polyphosphates have glass-transition temperatures between 81–108°C and polymer C, having a NO 2 group in the side chain phenyl ring, has the highest T g value. The polyphosphates obtained from bisphenol AF showed better thermal stabilities and higher LOI values than those obtained from bisphenol A. The polyphosphates have good flame retardancy, as indicated by high limiting oxygen index values in the range of 47–60. The water contact angles ( θ w) of all polyphosphates are in the range of 76–109°. The contact angles of polymers A and B are larger than other polyphosphates which contain more oxygen content or bromine atoms (polymers C, D and E).

Synthesis and characterization of wholly aromatic polyesters derived from 1-phenyl-2,6-naphthalene-dicarboxylic acid and aromatic diols

A series of new wholly aromatic polyesters was synthesized by melt polycondensation of 1-phenyl-2,6-naphthalenedicarboxylic acid (PNDA) and diacetates of various aromatic diols. The aromatic diols studied are hydroquinone (HQ), methylhydroquinone (MHQ), phenylhydroquinone (PHQ), (α-phenylisopropyl)hydroquinone (PIHQ), 2,6-naphthalenediol (2,6-ND), 1,4-naphthalenediol (1,4-ND), and 4,4′-biphenol (BP). These polyesters were characterized for their crystallinity, glass transition temperature (Tg), melting temperature (Tm), liquid crystallinity, and thermal stability. In general, crystallinity of the polyesters are very low and the Tg values of the polyesters range from 150 to 172°C depending on the structure of aromatic diols. All of the polymers formed nematic phases above their Tm or Tg. The polyesters derived from PHQ and PIHQ are soluble in chlorinated hydrocarbon solvents. The initial decomposition temperatures of the polyesters are above 400°C under N2 atmosphere. © 1996 John Wiley & Sons, Inc.

In vitro interference with hepatocellular transport of taurocholate by 1,1,2-trichloro-1,2,2-trifluoroethane

In recent years workers in our laboratory have shown that several industrial chlorinated aliphatic hydrocarbon solvents interfere with the transport of bile acids by hepatocytes and this interference may account for the raised concentration of serum bile acids that has been observed after occupational exposure to solvents. There has been concern about the effects on workers of a selective solvent used in degreasing electrical equipment, 1,1,2-trichloro-1,2,2-trifluoroethane (FC 113). However, this compound has not been investigated for effects on bile acid transport. Therefore we undertook the present study to examine the direct in vitro effects of FC 113 on uptake and efflux of bile acids by isolated rat hepatocytes. FC 113, at non-cytotoxic doses after a 20-min equilibration time, showed significant ( P < 0.05) inhibitory effects on the initial rate of uptake of taurocholate (TC), whereas accumulation of TC over an extended incubation time was not affected. Kinetic analysis revealed a non-competitive inhibition of TC uptake as evidenced by a decline in V max and an unaltered K m. The initial rate of efflux of TC and the continuous efflux of this model substrate from preloaded cells incubated with different doses of solvent were not significantly different from those of controls. However, the highest dose of solvent inhibited the process of efflux at the early time points. The data suggest that FC 113 interferes with bile acid transport in a reversible manner similar to that of the chlorinated aliphatic hydrocarbons. It would be expected, therefore, that this solvent would cause an increase in serum bile acids in exposed workers.

Determination of cohesion parameters for terpenoids such as 1,8-cineole using semi-empirical methods and calculations based on group contributions

Methods of estimation of cohesion parameters for terpenoids have been reviewed, both semi-empirical and group contribution calculations, and with 1,8-cineole from eucalyptus oil as an example. The various calculated values have been compared with each other and with values determined from experimental measurements, in order to assess the relative reliability of estimation methods. The information is required for the formulation of natural solvent blends to replace traditional hydrocarbon and chlorinated hydrocarbon solvents. A Hildebrand parameter of 17.6 MPa1/2 is the preferred value for 1,8-cineole.

Digestion and extraction of biological materials for zinc stable isotope determination by inductively coupled plasma mass spectrometry. Invited lecture

A separation method is described for rapidly removing zinc from interfering matrix components, such as chloride, from digested biological samples prior to measurement of zinc stable isotopes by ICP-MS. The method employs chelation of the zinc with trifluoroacetylacetone (TFA), extraction of the chelate with hexane, destruction of the chelate and dissolution of the zinc into nitric acid for determintion. Complete separation of the zinc from matrix salts is achieved, and the method does not employ chlorinated hydrocarbon solvents as used in earlier, similar schemes. Cerium from borosilicate glass tubes used in sample digestion was found to be a potential problem when measuring 70Zn, owing to the presence of 140Ce2+. This potential problem can be avoided by using quartz digestion tubes and/or correcting for any cerium by monitoring m/z 140. Accuracy was verified by an independent method, and examples of the use of stable isotopes of zinc as metabolic tracers in human metabolism are given. The detection limit for the ID method (3s of blank) was 0.7 µg Zn. An in-house urine pool was found to contain 1.18 ± 0.005 µg g–1 of Zn (n= 3) by ID and 1.17 ± 0.006 µg g–1 of Zn (n= 3) by AAS.

Synthesis and characterization of extended poly(phenylquinoxalines) containing carbonyl, ether and sulphide linking groups

A series of eight novel extended poly(phenylquinoxalines) (PPQs) containing carbonyl, ether and sulphide linking groups were prepared by polycondensation of 4,4'-bis(phenylglyoxalyl-4-phenoxy-4'-benzoyl)diphenyl sulphide, I-D, and 4,4'-bis(phenyl glyoxalyl-4-phenylthio-4'-benzoyl)diphenyl sulphide, 2-D, with four aromatic bis(o-diamines) in m-cresol. The primary objective of this study was to correlate the effect of these linkages on the various properties such as solubility, thermal stability and glass transition temperature of the PPQs. Polymerization of 1-D was carried out in an oil bath maintained at 195-200C whereas polymerization of 2-D was performed at ambient temperature. The polymers prepared were soluble in m-cresol. dimethylsulphoxide, N,N-dimethylacetamide, I-methyl-2-pyrrolidinone and chlorinated hydrocarbon solvents, and formed tough transparent, yellow fingernail-creasable films from chloroform solutions. The inherent viscosities ranged between 0.44 and 0.96 dl g' '. The glass transition temperatures were nearly identical for both systems and ranged from 217-231 'C for polymers prepared from l-D and from 215-233"C for polymers prepared from 2-D. The PPQs having carbonyl and stJlphide linking groups had higher thermal stability in comparison to PPQs having carbonyl, ether and sulphide linkages. The temperature of 10% weight loss for I-D ranged from 484-496 'C in air and 485-516"C in helium whereas those for 2-D ranged from 538-579 XC in air and 522-549 in helium.

Re: Chlorinated hydrocarbon solvents: Substituting our way toward human carcinogenicity

American Journal of Industrial MedicineVolume 27, Issue 3 p. 447-448 Letter to the Editor Re: Chlorinated hydrocarbon solvents: Substituting our way toward human carcinogenicity Stephen A. Frangos MD, MPH, Corresponding Author Stephen A. Frangos MD, MPH Division of Occupational and Environmental Medicine, University of Southern California, Los Angeles, CA 90033Department of Preventive Medicine, Division of Occupational and Environmental Medicine, University of Southern California, 1420 San Pablo Street, PMB B-306, Los Angeles, CA 90033Search for more papers by this authorJohn M. Peters MD, SCD, John M. Peters MD, SCD Division of Occupational and Environmental Medicine, University of Southern California, Los Angeles, CA 90033Search for more papers by this author Stephen A. Frangos MD, MPH, Corresponding Author Stephen A. Frangos MD, MPH Division of Occupational and Environmental Medicine, University of Southern California, Los Angeles, CA 90033Department of Preventive Medicine, Division of Occupational and Environmental Medicine, University of Southern California, 1420 San Pablo Street, PMB B-306, Los Angeles, CA 90033Search for more papers by this authorJohn M. Peters MD, SCD, John M. Peters MD, SCD Division of Occupational and Environmental Medicine, University of Southern California, Los Angeles, CA 90033Search for more papers by this author First published: March 1995 https://doi.org/10.1002/ajim.4700270315AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume27, Issue3March 1995Pages 447-448 RelatedInformation

Synthesis of fluorine-containing polyphosphonates: low temperature solution polycondensation of bisphenol AF and phenylphosphonic dichloride

This paper describes the synthesis of polyphosphonates from the reaction of phenylphosphonic dichloride (PPD) with bisphenol AF (BPAF) and its derivatives in a chlorinated hydrocarbon solvent under low temperature conditions. The polyphosphonates obtained were characterized by i.r., inherent viscosity, differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction and molar mass. The polyphosphonate obtained from BPAF has a larger inherent viscosity by 0.50 dl g −1 and a higher glass transition temperature than those derivatives which contain flexible oxyethylene units or bromine atoms. Polyphosphonate derived from BPAF begins to lose 10% of its mass at 415°C and the mass percentage remaining at 700°C is 20.3% under nitrogen. The X-ray diffraction patterns revealed that almost all the polymers were amorphous, except for one polymer which was semicrystalline. The PPD/BPAF and PPD/ 3,3′,5,5′-tetrabromo bisphenol AF polymers have good flame retardancy, as indicated by high limiting oxygen index values of 43 and 65, respectively. The contact angles of PPD/BPAF polymer formed by water, glycerine and ethylene glycol were larger than those of other polyphosphonates which contain flexible oxyethylene units or bromine atoms.

Migration of chlorinated hydrocarbon solvents through coventry sandstone rock columns : Bourg, A C M; Degranges, P; Mouvet, C; Sauty, J P J HydrolV149, N1/4, Aug 1993, P183–207

Migration of chlorinated hydrocarbon solvents through coventry sandstone rock columns : Bourg, A C M; Degranges, P; Mouvet, C; Sauty, J P J HydrolV149, N1/4, Aug 1993, P183–207

Chemical Processing in high-pressure aqueous environments. 3. Batch reactor process development experiments for organics destruction

A high-pressure (20 MPa) and high-temperature (350 C) liquid water processing environment was used to treat various wastewaters and model compounds. Organics were converted to methane and carbon dioxide in the presence of catalysts. Functional types included hydrocarbons, both aliphatic and aromatic; phenolics and other oxygenates; chlorinated hydrocarbon solvents; and sodium salts of organic acids. Tests with aqueous nickel ion showed negligible catalytic activity. Noncatalytic hydrolysis of sodium cyanide, carbon tetrachloride, and chloroform was also demonstrated. Ammonium destruction was proven by reaction with nitrate at these processing conditions. Several examples of test results with actual industrial waste streams showed that this process can be effectively used with catalysts to clean wastewater and recover waste organics as useful fuel gas.