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PubMed1976

[Why must we manufacture vinyl chloride and polyvinyl chloride?].

The manufacture of PVC is necessary for supplying the demands of modern society, for maintaining the equilibrium in the chemical industry such as the manufacture of caustic soda solution-chlorine by means of rocksalt electrolysis, and for the safe disposal of chlorine for environmental reasons. The manufacture of vinyl chloride and dichloroethane is illustrated. The conventional processing of PVC into consumer goods, after treatment of rigid and plasticized PVC compounds or granulate, is demonstrated.

Chemical Industry↗
PubMedDate not supplied

[Reanalysis of mortality in a petrochemical plant producing vinyl chloride and polyvinyl chloride].

OBJECTIVE: To study cancer mortality among main subgroups of workers employed in VC/PVC production potentially exposed to toxics and carcinogens. MATERIALS AND METHODS: We reanalyzed the mortality of 1,658 males (follow up 1972-1995; 35,626 person years; 170 deaths) by Poisson regression, adjusting for age, age at hiring, calendar period, length of exposure and latency. We calculated the relative risks (RR) and the 95% confidence intervals (CI) for PVC baggers (n. = 197), PVC compound (n. = 403) and autoclave (n. = 209) workers. As an internal reference we used two groups of workers: technicians and employees (main reference: n. = 202 subjects), with the group of other blue collar workers (n. = 639) added for statistical purposes only (minor reference: n. = 841 subjects). RESULTS: Pooling the four subgroups of exposed workers, the comparison with the main reference group allowed us to detect increased mortality from all causes of death (RR = 2.09; CI = 1.09-4.00; 160 deaths), all tumours (RR = 1.53; ns; 81 deaths), lung cancer (RR = 2.05; ns; 29 deaths) and cardiovascular diseases (RR = 3.57; ns; 29 deaths). The analysis for each specific subgroup revealed increased mortality from all causes of death among both PVC baggers (RR = 2.66; CI = 1.27-5.59) and PVC compound workers (RR = 2.68; CI = 1.36-5.27). Comparison of the minor reference group with the overall population of exposed workers showed increased RRs for other diseases, namely, liver tumour (RR = 4.08; ns; 9 deaths), lymphomas and leukaemia (RR = 2.97; ns; 7 deaths) and liver cirrhosis (RR = 3.30; ns; 11 deaths). The analysis for each specific subgroup revealed significantly increased RR for all tumours among PVC compound workers (RR = 1.74; CI = 1.06-2.85), for lung cancer among PVC baggers workers (RR = 3.04; CI = 1.15-7.99) and for liver cancer (RR = 9.57; CI = 1.69-54.1) and liver cirrhosis (RR = 6.32; CI = 1.37-29.07) among autoclave workers. In addition, the two deaths from brain tumour were observed among PVC compound workers. CONCLUSIONS: To highlight the risk previously reported in the literature and to reduce the possible dilution effect (due to comparison bias, healthy worker effect), it proved methodologically pivotal to separate exposed and probably unexposed workers (considered as an internal reference group).

Adult↗
PubMed1978

Headspace sampling and gas-solid chromatographic determination and confirmation of greater than or equal to 1 ppb vinyl chloride residues in polyvinyl chloride food packaging.

The determination and confirmation of residual vinyl chloride (VC) in polyvinyl chloride (PVC) food packaging materials are described. PVC packaging materials are dissolved in dimethylacetamide (DMAC). VC is sparged from solution with helium gas and collected in sealed vials of ethanol. VC is detected and quantitated by using a headspace sampling technique and standard gas-solid chromatography (GSC) with flame ionization detection. GSC peak heights of about 5% full scale deflection are obtained for samples of PVC containing 1 ppb VC. Polymer samples taken from tubing, blood bags, food packaging films, bottles, and unprocessed resin were analyzed. Residual VC levels ranged from 0.3 to 913 ppb. VC was confirmed by GSC-mass spectrometry, using selected ion recording of m/z 62 and 64 in conjunction with full mass scans to identify components eluting near VC.

Chromatography, Gas↗
PubMed1988

Delivery of paraldehyde in 5% dextrose and 0.9% sodium chloride injections through polyvinyl chloride i.v. sets and burettes.

The delivery of paraldehyde in 5% dextrose injection and 0.9% sodium chloride injection was studied, and the potential interaction between paraldehyde and plastic i.v. containers and sets was evaluated. Paraldehyde was mixed with either 5% dextrose injection or 0.9% sodium chloride injection in polyvinyl chloride (PVC) bags to form a 4% solution. The bags were fitted with standard i.v. administration sets or burettes with administration sets. The solutions were allowed to drip through the i.v. sets for six hours at room temperature. Samples were taken from the i.v. bag or burette and from the distal end of the i.v. sets at zero, two, four, and six hours. Paraldehyde concentrations were measured using a stability-indicating gas chromatographic method, and the presence of plasticizers was detected by a scanning ultraviolet spectrophotometer. The cumulative amount of paraldehyde delivered at the end of the administration set at six hours was 84% for 5% dextrose solutions in burettes, and 89% or 90% for all other solutions and i.v. sets. An ultraviolet-light-absorbing substance appeared in some of the samples, although a relationship between the presence of this substance and type of solution, time of sampling, or site of sample did not emerge. Particulate matter appeared after two hours in all burettes. Approximately 10%-16% of paraldehyde in 5% dextrose or 0.9% sodium chloride injection is lost when delivered from PVC i.v. bags through standard i.v. administration sets and burettes over a six-hour period.(ABSTRACT TRUNCATED AT 250 WORDS)

Drug Stability↗
PubMedDate not supplied

Characterization of emissions of dioxins and furans from ethylene dichloride, vinyl chloride monomer and polyvinyl chloride facilities in the United States. Consolidated report.

This is the consolidated report of emissions of PCDD/F from facilities in the organic chemical manufacturing chain leading to polyvinyl chloride. Data have been gathered from facilities in the US and Canada from a number of manufacturers and at various steps in the manufacturing process. Estimates of US emissions or transfers of PCDD/F were generated on an "Upper Bound" and "Most Likely" basis. The Most Likely estimate of US emissions of PCDD/F to the open environment, that is, air, water and land surface by facilities in this chain, based on evaluation of non-detects at one-half the detection limit is about 12 g I-TEQ per year. On this same basis, an estimated 19 g is disposed of in secure landfills.

Chemical Industry↗
PubMed2001

Urinary thiodiglycolic acid levels for vinyl chloride monomer-exposed polyvinyl chloride workers.

Thiodiglycolic acid (TdGA) is the major metabolite of vinyl chloride monomer (VCM) detected in human urine. Although urinary TdGA has been reported to be associated with ambient VCM exposure, the relationship between urinary TdGA and a low level of air VCM is not clear. Questionnaires were administered to 16 polyvinyl chloride manufacturing workers to obtain a detailed history of occupation and lifestyle. For each worker, personal air monitoring for VCM was performed and a time-weighted average for VCM exposure was calculated. The urinary TdGA levels at the end of a work shift, and at the commencement of the next shift, were also assessed for each worker. Urine analysis revealed that TdGA levels at the beginning of the next shift were higher than those at the end of that shift. Workers experiencing a VCM exposure greater than 5 ppm in air revealed a urinary TdGA level significantly greater than those experiencing a VCM exposure of less than 5 ppm (P < 0.05). The best fit of regression for urinary TdGA on air VCM was Y = 1.06 + 0.57X for urine collected at the commencement of the following work shift, where X is the air VCM concentration and Y is the urinary TdGA concentration (r2 = 0.65, P < 0.01). We conclude that the urinary TdGA level is best detected at the commencement of the next shift and that it can be used as an exposure marker for polyvinyl chloride workers when the air VCM level to which they are exposed is greater than 5 ppm.

Adult↗
PubMed1992

Stability and sorption of FK 506 in 5% dextrose injection and 0.9% sodium chloride injection in glass, polyvinyl chloride, and polyolefin containers.

The effects of the diluent, the storage container, light, and infusion through various types of tubing on the stability and sorption of FK 506 were studied. Solutions of FK 506 in 0.9% sodium chloride injection or 5% dextrose injection were stored at room temperature (24 +/- 2 degrees C) in glass i.v. bottles, polyvinyl chloride (PVC) minibags, and polyolefin containers. FK 506 solution in 0.9% sodium chloride injection was stored in plastic syringes at room temperature and either exposed to normal room light or stored in the dark. FK 506 solution in 5% dextrose injection was placed in plastic syringes and infused through PVC anesthesia extension tubing, PVC i.v. administration set tubing, and fat emulsion tubing over a two-hour period. The infused samples and samples collected from the containers and syringes at intervals up to 48 hours were analyzed for FK 506 concentration by high-performance liquid chromatography. FK 506 concentrations remained greater than 90% of initial concentration for admixtures in 5% dextrose injection stored in glass bottles for 48 hours and for admixtures in 5% dextrose injection or 0.9% sodium chloride injection stored in polyolefin containers for 48 hours. No change in concentration was measured for admixtures in 0.9% sodium chloride injection stored in plastic syringes, and exposure to light did not affect the stability of FK 506 solution. No substantial change in concentration occurred in FK 506 solution in 5% dextrose injection infused through PVC anesthesia extension tubing, PVC i.v. administration set tubing, or fat emulsion tubing. FK 506 admixtures prepared with 5% dextrose injection or 0.9% sodium chloride injection should be stored in polyolefin containers. If polyolefin containers are not available, solutions should be prepared with 5% dextrose injection and stored in glass bottles.

Adsorption↗
PubMed1997

Fractal Dimensionality of Vinyl Chloride Monomer Adsorption on Polyvinyl Chloride Particles

The extent of adsorption of vinyl chloride monomer (VCM) on polyvinyl chloride (PVC) beads of various size was examined using the inverse gas chromatography technique at 288, 295, 303, and 313 K. The sizes of the PVC beads were 60-80, 100-120, and 150-200 mesh. On them the specific retention volume Vg (ml/g) of the injected gaseous monomer was determined. Vg depends on the mean particle size &dmacr; of PVC beads according to the relationship log Vg = (D - 3)log &dmacr;, from which the mass fractal D values were determined between 2.95 and 2.63 depending on the temperature and the dilution of monomer. Higher temperatures (313 K) are associated with lower D values (2.63-2.67), whereas lower temperatures (288 K) are associated with higher D values (2.87-2.95). These results suggest that the PVC behaves more as a two-dimensional material in relation to VCM adsorption at higher temperatures, whereas at lower temperatures it looks more like a three-dimensional Euclidean solid.

Journal Article↗
PubMed2003

XRCC1, CYP2E1 and ALDH2 genetic polymorphisms and sister chromatid exchange frequency alterations amongst vinyl chloride monomer-exposed polyvinyl chloride workers.

Vinyl chloride monomer (VCM) is a known human carcinogen, which may be metabolized by cytochrome P450 2E1 (CYP2E1), aldehyde dehydrogenase 2 (ALDH2), and glutathione S-transferase T1 (GSTT1). A DNA-repair gene, X-ray repair cross-complementing group 1 ( XRCC1, exon 10), may also be implicated in the process of VCM-related carcinogenesis. Thus, VCM-exposed workers with inherited susceptible metabolic and DNA-repair genotypes may experience an increased risk of genotoxiciy. This study was designed to investigate whether metabolic and DNA-repair genotypes affected sister chromatid exchange (SCE) frequency in occupationally VCM-exposed workers from polyvinyl chloride (PVC) manufacturing plants. Study subjects comprised 61 male workers having experienced VCM exposure, and 29 male controls. Questionnaires were administered to obtain detailed histories of cigarette-smoking habits, alcohol consumption behavior, and occupation. The frequency of SCE in peripheral lymphocytes was determined using a standardized method, and genotypes of CYP2E1, ALDH2, GSTT1 and XRCC1 were identified by the polymerase chain reaction (PCR) procedure. Our results demonstrated that smoking, age and VCM exposure and XRCC1 ( P=0.03), CYP2E1 ( P=0.04), and ALDH2 ( P=0.08) were significantly associated with an increased SCE frequency. Further analysis of gene combinations, including CYP2E1, ALDH2 and XRCC1, revealed an increased trend for these genotypes to influence SCE frequencies for the low VCM-exposure group ( P<0.01), but not so for the high VCM-exposure group ( P=0.29) or for controls ( P=0.49). These results suggest that workers with susceptible metabolic and DNA-repair genotypes, may experience an increased risk of DNA damage elicited by VCM exposure.

Adult↗
PubMed1990

Mortality and cancer morbidity in workers exposed to low levels of vinyl chloride monomer at a polyvinyl chloride processing plant.

To study whether exposure to low levels of vinyl chloride monomer (VCM) causes increased risk for cancer morbidity and death from ischemic heart disease, a cohort study was performed among 2,031 male workers at a polyvinyl chloride (PVC) processing plant who had been employed for at least 3 months during the period 1945-1980. An almost significantly increased total mortality (SMR = 116, 95% CI 99-136) was found. Deaths caused by violence or intoxication were significantly increased (SMR = 153, 95% CI 109-213), but not deaths from ischemic heart disease (SMR = 100, 95% CI 73-135). A significant increase in total cancer morbidity was observed (SMR = 128, 95% CI 101-161). Respiratory cancers were significantly increased (SMR = 213, 95% CI 127-346). Furthermore, six brain tumors (vs. 2.6 expected) were observed. This increase, however, was not significant (SMR = 229, 95% CI 84-498). No liver hemangiosarcoma was observed. Applying a latency period of greater than or equal to 10 years from start of employment did not change the risk patterns. There were no significant exposure-response associations between exposure estimates for VCM, asbestos, and plasticizers and cancer morbidity.

Adult↗
PubMedDate not supplied

Design and in vitro evaluation of polyvinyl chloride microcapsules containing sulphamethoxazole.

Polyvinyl chloride microcapsules containing sulphamethoxazole have been prepared by phase separation coacervation in non-aqueous solvents. Phase separation of the polyvinyl chloride in the solution of chloroform was achieved with n-hexane. Scanning electron micrographs revealed uniform encapsulation of the sulphamethoxazole particles. In vitro dissolution studies were conducted under changing pH conditions. The reproducibility of the in vitro drug release was highly significant. The mechanism of drug release was suggested as an integrated process of diffusion controlled dissolution. Controlled drug release was obtained over a prolonged period of 8 h.

Capsules↗