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The toxicity of methylisocyanate for rats
The results of previous experiments on rats are used to derive a concentration-time mortality-response relationship. Contrary to gases such as chlorine or ammonia whose lethality depends on concentration, it seems that in the case of methylisocyanate, the duration of exposure is dominant in determining the mortality response. A prolonged exposure to MIC may have therefore been the cause of the high number of victims in Bhopal in India. One should consider in this connection that MIC does not have a well recognisable odour at concentrations up to 24mg/m3.
Journal of Hazardous Materials, Dec. 1985, Vol.12, No.3, p.309-311. Illus. 3 ref.
Swensson Å, Andersson K.
Nordic expert group for documentation of threshold limit values - 58. Diisocyanates
Nordiska expertgruppen för gränsvärdesdokumentation - 58. Diisocyanater [en sueco]
A review of the literature disclosed that a hygienic standard for diisocyanates should be based on their effect on the respiratory organs. Their most serious effect is hyperreactivity in people exposed to them. This hyperreactivity produces serious symptoms, even when exposure is to low air concentrations. A threshold limit value cannot protect hyperreactive people but a low value will contribute to a reduction in the incidence of hyperreactivity.
Arbetarskyddsstyrelsen, Publikationsservice, 171 84 Solna, Sweden, 1985. 82p. 202 ref.
Venables K.M., Dally M.B., Burge P.S., Pickering C.A.C., Taylor A.J.N.
Occupational asthma in a steel coating plant
This is a report on the epidemiological investigation that lead to the identification of toluene diisocyanate (TDI) as the agent responsible for occupational asthma affecting 21 workers in a steel coating plant. The symptoms developed after a supplier had modified the coating, thereby allowing the liberation of TDI during the process. Removing TDI from the process led to the elimination or reduction of the symptoms in 17 of the workers.
British Journal of Industrial Medicine, Aug. 1985, Vol.42, No.8, p.517-524. Illus. 5 ref.
This data sheet covers both the 2,4-isomer and the 2,6-isomer of toluene diisocyanate (TDI), used in the manufacture of polyurethane foam. Coverage: properties; occupational exposure limits (0.02mg/m3 for 8h TWA, 0.07mg/m3 for 10min TWA); fire hazards (even low vapour concentrations of combustion products can be lethal); extinguishant (preferably dry powder or carbon dioxide); toxicity and biological hazards (acute effects: skin and respiratory irritation, poisoning if ingested; chronic effects: respiratory sensitisation; carcinogenesis by the 2,4-isomer); handling and storage; medical surveillance; safety precautions; leakage and spills; first aid.
Safety Practitioner, May 1985, Vol.3, No.5, p.32-33. 1 ref.
Collection and determination of methyl carbamate in air
Methyl carbamate vapour is collected on silica gel tubes, desorbed with water and analysed by gas chromatography. An average collection efficiency of 96.3% was obtained at concentrations ranging from 0.3 to 6.0mg/m3. There was no loss in collection efficiency at a relative humidity of 84%.
American Industrial Hygiene Association Journal, Sep. 1985, Vol.46, No.9, p.514-516. Illus. 1 ref.
Nielsen J., Sangö C., Winroth G., Hallberg T., Skerfving S.
Systemic reactions associated with polyisocyanate exposure
A spray painter suffered recurrent attacks of chills, fever, general malaise, dispnoea, headache, arthralgia and leukocytosis, a few hours after exposure to aerosols of varnishes containing polymers of hexamethylene and tolylene diisocyanate. Immunologic tests revealed an increase in serum immunoglobulin G level. Polyisocyanate levels in the workroom ranged from 1.5 to 7.4mg/m3 (5.4-30.0µmol NCO/m3).
Scandinavian Journal of Work, Environment and Health, Feb. 1985, Vol.11, No.1, p.51-54. 16 ref.
Johnson A., Chan-Yeung M., Maclean L., Atkins E., Dybuncio A., Cheng F., Enarson D.
Respiratory abnormalities among workers in an iron and steel foundry
A study of the health of 78 workers in an iron and steel foundry in British Columbia (Canada), and of 372 controls (workers in a railway repair yard). The foundry workers were exposed to the chemical binding system PepSet, consisting of diphenylmethane diisocyanate (MDI), phenol formaldehyde, and a catalyst containing a pyridine derivative. They were also exposed to silica particulates. The study included a questionnaire survey, chest radiography, allergy skin tests, pulmonary function tests, methacholine inhalation tests, and measurements of dust and MDI levels. The foundry workers had significantly more respiratory symptoms and significantly lower respiratory function indicators than did the controls. 3 of the workers had radiographic signs of pneumoconiosis and 12 had asthma, probably caused by sensitisation to MDI.
British Journal of Industrial Medicine, Feb. 1985, Vol.42, No.2, p.94-100. 31 ref.
Rando R.J., Hammad Y.Y.
Modified Marcali method for the determination of total toluenediisocyanate in air
The Marcali method for measuring airborne toluenediisocyanate (TDI) was evaluated for its response to the 2 isomers of the compound. The absorbance of the chromophore obtained from 2,6-TDI is about 47% lower than that from the 2,4-isomer when measured at 550nm. A simple modification of the method involving changes in diazotisation time and temperature is proposed to eliminate the isomer effect.
American Industrial Hygiene Association Journal, Apr. 1985, Vol.46, No.4, p.206-210. Illus. 7 ref.
Gee J.B., Morgan W.K.C.
A 10-year follow-up study of a group of workers exposed to isocyanates
The changes in the ventilatory capacity of 68 workers continuously exposed to toluene diisocyanate and diphenylmethane diisocyanate were determined during the period 1971-1981. No significant respiratory function decrement during workshifts was noted in any of the subjects. Isocyanate levels were below the exposure limits in use.
Journal of Occupational Medicine, Jan. 1985, Vol.27, No.1, p.15-18. 11 ref.
Respirator cartridge evaluation for isocyanate-containing Imron and Centari enamels
Imron and Centari enamels are spray painting formulations used widely in auto-body repair shops. The paint activator contains about 33% of a polyaliphatic isocyanate derived from hexamethylene diisocyanate. Organic vapour respirator cartridges were exposed to atmospheres containing the paints in spray form during laboratory tests. Breakthrough for the paint solvents (acetone, ethyl acetate) occurred after 10 to 15h. Isocyanate breakthrough did not occur for either paint, even after 25h exposure. The experiment suggests that organic vapour respirator cartridges could be used for protection against isocyanates during spray painting. The smell of the solvent breakthrough would serve as an alarm well before reaching the breakthrough time for the isocyanate.
American Industrial Hygiene Association Journal, Jan. 1985, Vol.46, No.1, p.39-44. 5 ref.
Two-year observation of pulmonary function in workers exposed to low concentrations of toluene diisocyanate
Pulmonary effects were investigated in 106 workers exposed to toluene diisocyanate (TDI) and 39 referents in 1980 and in 64 exposed workers and 21 referents in the 2-year follow-up study ending in 1982. Individual, time-weighted average (TWA) exposure concentrations measured by personal monitors averaged approximately 0.001ppm in each year. No differences were observed in the means of the pulmonary functions and their individual daily changes between the TDI workers and the referents. The incidence of respiratory symptoms in the TDI workers was not significantly higher than in the referents, but there was irritation of the eyes and throat probably due to peak exposure to TDI and/or co-existing irritants. These results suggest that TDI exposure at the 0.001ppm level does not produce adverse pulmonary effects except in cases of hypersensitivity.
International Archives of Occupational and Environmental Health, 1984, Vol.55, No.1, p.1-12. 26 ref.
Sciarra G., Innocenti A., Bozzi N.
Comparison of three methods of sampling and analysis of toluene diisocyanate (TDI) in air
Confronto di tre metodi di campionamento e analisi del toluen-diisocianato (TDI) in aria [en italiano]
High-performance liquid chromatography was slightly more sensitive and accurate in the determination of TDI concentration in a laboratory exposure chamber than were colorimetry and continuous-tape monitoring. When rapid response time is necessary (such as during a bronchial provocation test), continuous-tape monitoring is to be preferred.
Medicina del lavoro, Nov.-Dec. 1984, Vol.75, No.6, p.491-496. Illus. 13 ref.
Baruffini A., Cirla A., Pisati G., Sala C.
TDI-induced occupational asthma in workers touching up textile printing frames
Asma professionale da toluendiisocianato nei ritoccatori di quadri per la stampa dei tessuti [en italiano]
Case study of 3 workers in the textile printing industry who developed bronchial asthma. The workers' job involved touching up the printing frame using polyurethane paints containing low levels (below 0.7%) of tolylene diisocyanate (TDI). The symptoms and clinical diagnostic signs of the asthma were similar to those of TDI asthma in other industries. Diagnosis was on the basis of clinical examination and the specific bronchial challenge test. The airways reaction was non-immediate.
Medicina del lavoro, Sep.-Oct. 1984, Vol.75, No.5, p.393-398. Illus. 15 ref.
Collinson J.G., Rajhans G.S.
Automotive body repair shop hazards
Five auto body shops in Ontario were surveyed to determine the degree of hazard associated with the use of isocyanate-containing paints and hardeners. Free isocyanate levels ranged from <0.001ppm to 0.003ppm. However, the combined exposure to monomeric and polymeric forms of isocyanates in paints could reach levels >0.005ppm. Suggestions are made regarding other hazards (noise, solvents, pigments, body fillers), exhaust ventilation and personal respiratory protection.
Occupational Health in Ontario, Oct. 1984, Vol.5, No.4, p.156-171. Illus. 10 ref.
Candura F., Moscato G.
Do amines induce occupational asthma in workers manufacturing polyurethane foams?
12 workers occupationally exposed to polyurethane foams and with symptoms of wheezing and breathlessness were subjected to a bronchial provocation test with methacholine (to establish a dose-response curve), toluenediisocyanate (TDI) at 0.01ppm, and toluenediamine (TDA) at 1.31mg/m3 and at 3.21mg/m3. High sensitivity to methacholine (positive response below 1000g administered) was shown in 10 subjects. All the subjects had positive reactions to TDI, and none of them responded to TDA at either concentration. These data suggest that TDI is the agent for the respiratory symptoms, and that TDA does not produce asthma.
British Journal of Industrial Medicine, Nov. 1984, Vol.41, No.4, p.552-553. Illus. 10 ref.
Holness D.L., Broder I., Corey P.N., Booth N., Mozzon D., Guirguis S., Nazar M.A.
Respiratory variables and exposure-effect relationships in isocyanate-exposed workers
Respiratory variables were compared in 95 workers exposed to tolylene diisocyanate in the production of plastic foam and 37 control workers. Exposed workers had a higher frequency of cough and shortness of breath and a significantly lower frequency of family history of asthma, hay fever and bronchitis. The exposed workers had slightly lower baseline lung function than the controls but demonstrated significantly larger declines in their pulmonary function over the work shift. Both groups showed some intraday and intraweek variation in lung function. Changes in lung function over the work shift varied with job category, with the largest occurring in finishing-area workers. A gradation of response was observed when exposure was categorised as nil, low, or high, but no exposure-effect relationship was demonstrated by regression analysis of area or personal results.
Journal of Occupational Medicine, June 1984, Vol.26, No.6, p.449-455. 30 ref.
Paint products containing isocyanates
Verfprodukten die isocyanaten bevatten [en holandés]
Introduction on the isocyanates contained in certain two-component paints (isocyanates + hydroxyacrylates, isocyanates + hydroxyesters or hydroxyethers, isocyanate-tar combinations) and in one-component wire enamels with blocked isocyanates, and on their nomenclature. The main health hazard is sensitisation, with differing effects according to whether a person is sensitised or not. Preventive measures include good natural ventilation and, if work is done indoors or when the paint is sprayed, mechanical ventilation and wearing of respiratory protective equipment. Other aspects covered are disposal of isocyanate spills, isocyanate-impregnated rags and empty containers, cleaning of work clothing, removal of old paint coats, welding and cutting of painted structures, soldering of enamelled wire, dealing with fires in stores and workshops, labelling of products, first aid, TLVs, medical surveillance, Dutch legislation and data sheets.
De veiligheid, Aug. 1984, Vol.60, No.8, p.391-399. Illus.
Health and Safety Executive
Isocyanates: Toxic hazards and precautions
This round-up of the health hazards posed by exposure to the isocyanates covers: toxic effects; the control limits adopted in the United Kingdom on 1 Feb. 1983 (8h TWA: 0.02mg/m3, 10min TWA: 0.07mg/m3, both expressed in terms of free isocyanate groups; medical supervision; first aid; protective clothing and respiratory protective equipment; legislative requirements; properties of commonly used isocyanates (toluene diisocyanate, diphenylmethanediisocyanate, isocyanate pre-polymers); storage and handling; toxic hazards and precautions associated with specific processes using isocyanates (flexible foams, rigid foams, other uses).
H.M. Stationery Office, 49 High Holborn, London WC1V 6HB, United Kingdom, Mar. 1984. 10p. 11 ref. Price: £1.50.
Rosenberg C., Tuomi T.
Airborne isocyanates in polyurethane spray painting: Determination and respirator efficiency
Samples were collected on reagent impregnated glassfiber filters and analysed by HPLC. Average recoveries of the HDI monomer (hexamethylenediisocyanate) and the HDI oligomer were 97 and 92% respectively. Measured concentrations of HDI in air exceeded frequently the exposure limit of 0.07mg/m3 in use in Finland. The sampling technique was used to measure HDI levels inside various types of respirators worn by the painters. The respirators with only chemical cartridges were efficient in retaining the monomer but an average 40% penetration was measured for the oligomer. A combination of filter and chemical cartridge was efficient in retaining both contaminants.
American Industrial Hygiene Association Journal, Feb. 1984, Vol.45, No.2, p.117-121. 21 ref.
Bagon D.A., Warwick C.J., Brown R.H.
Evaluation of total isocyanate-in-air method using 1-(2 methoxyphenyl)piperazine and HPLC
This high-pressure liquid chromatography method has been developped to meet the requirements of the "common control limit" for workplace exposure to all isocyantes recently promulgated in the United Kingdom (20µg NCO/m3 for an 8h TWA). It has been modified to measure both the monomer and prepolymer. A dual detection system (electrochemical and UV) is used to identify the isocyanate derivatives and quantify them by reference to a monomer standard. The precision of the method is >10% over the range 35 to 140µg(NCO)/m3 for a 10min sample. Accuracy is ±19%.
American Industrial Hygiene Association Journal, Jan. 1984, Vol.45, No.1, p.39-43. 6 ref.
Baur X., Dewair M., Römmelt H.
Acute airway obstruction followed by hypersensitivity pneumonitis in an isocyanate (MDI) worker
Case study of a man who had developed an acute asthmatic reaction followed by hypersensitivity pneumonitis after occupational exposure to diphenylmethane diisocyanate (MDI), used in the manufacture of polyurethane foam. Challenge testing by MDI and the detection of specific IgG antibodies to various isocyanate-human serum albumin conjugates suggest immunological cross-reactivity between different isocyanates.
Journal of Occupational Medicine, Apr. 1984, Vol.24, No.4, p.285-287. Illus. 11 ref.
Bertrand J.P., Wantz J.M., Heintz P., Zitter M.
Pathologic conditions related to the use of isocyanates in Lorraine coal mines
Pathologie liée à l'utilisation des isocyanates dans les mines de charbon de Lorraine [en francés]
Diisocyanates of the type 4,4-diphenylmethane diisocyanate (MDI), used to consolidate brittle ground, cause acute skin contact problems, particularly in the upper part of the body, with frequent involvement of the eyes. Asthma-like respiratory problems also occur, accompanied by an obstructive syndrome or by alveolocapillary exchange impairment. An immunological mechanism is involved. An epidemiologic survey showed no evidence of significant differences between exposed and unexposed miners, or between affected workers and controls, as far as average vital capacity values, FEV1 values and the FEV1/VC ratio are considered. With the increasing use of polyurethane, phenol-formaldehyde and urea-formaldehyde resins, it is recommended that occupational health services extend their preventive measures.
Archives des maladies professionnelles, 1984, Vol.45, no.1, p.3-9. 16 ref.
Regulation respecting isocyanates - made under the Occupational Health and Safety Act
This regulation presented in booklet form includes: the scope of the regulation in which the TWA exposure limit to all isocyanates is set at 0.005ppm or 0.2 micromole isocyanates/m3 with a ceiling value of 0.02ppm or 0.8 micromole isocyanates/m3 of air; a code of respiratory protective equipment for isocyanates; a code for sampling and analysing airborne isocyanates; a code of medical surveillance of workers.
Ontario Ministry of Labour, Occupational Health and Safety Division, 400 University Ave., Toronto, Ontario M7A 1T7, Canada, 1983. 79p.
Andersson K., Gudéhn A., Hallgren C., Levin J.O., Nilsson C.A.
Monitoring 1,6-hexamethylene diisocyanate in air by chemosorption sampling
A sampling procedure in which 1,6-hexamethylene diisocyanate (HDI) is trapped on a chemosorption tube containing 9-(N-methylaminomethyl)anthracene adsorbed on Amberlite XAD-2 is described. Simultaneous sampling with a fritted-glass bubbler and by the chemosorption technique at 2 factories using HDI as a hardener in two-component paints showed equal collection efficiencies when 3.5-22l air samples were used. For samples >20l, the collection efficiency of the fritted-glass bubbler decreased. Additional peaks in the chromatogram from the solvent sampler are believed to be due to polymeric derivatives of HDI.
Scandinavian Journal of Work, Environment and Health, Dec. 1983, Vol.9, No.6, p.497-503. Illus. 22 ref.
Health and Safety Executive
Isocyanates - Medical surveillance
Contents of this guidance note: Clinical effects of exposure to isocyanates (effects on the eyes, skin, respiratory system); appropriate tests for the pre-employment examination and the periodic examination of workers exposed to isocyanates; interpretation of spirometric results; first aid instructions.
H.M. Stationery Office, 49 High Holborn, London WC1V 6HB, United Kingdom, Aug. 1983. 3p. 6 ref. Price: £0.50.
Health and Safety Executive
Organic isocyanates in air - Laboratory method using 1-(2-methoxyphenyl) piperazine solution and high performance liquid chromatography
Contents of this guidance note: Properties, uses, toxicity and first aid in case of massive exposure to organic isocyanates; determination method (sampling through a glass impinger containing the absorbing solution of 1-(2-methoxyphenyl) piperazine; the organic isocyanates react to form urea derivatives; the resulting solution is concentrated and analysed with a high performance liquid chromatograph equipped with an ultraviolet and an electrochemical detector; the total isocyanate concentration is calculated from the sum of all isocyanate-derived chromatograph peaks). Scope: suitable for measurement over periods in the range of 10min to 8h, both for personal and area sampling. Analytical range: 7-140µg NC0/m3 for 10l air samples. Precision: 10%. Aromatic amines and the presence of several isocyanate types will provide interference.
Health and Safety Executive Sales Point, St. Hugh's House, Stanley Precinct, Bootle, Merseyside L20 3QY, United Kingdom, Mar. 1983. 5p. Illus. 12 ref. Price: £1.00.
Andersson K., Gudehn A., Levin J.O., Nilsson C.A.
A comparative study of solvent and solvent-free sampling methods for airborne 4,4'-diphenylmethane diisocyanate (MDI) generated in polyurethane production
The sampling systems evaluated in the field were: glass fibre filters; cellulose acetate filters; XAD-2 sorbent and natural sponge impregnated with 9-(N-methylaminomethyl)anthracene (MAMA); glass fibre filters impregnated with N-p-nitrobenzyl-N-n-propylamine (NBPA); impingers containing MAMA in toluene, NBPA in toluene, and dimethylformamide-HCl solutions. All the solvent-free methods were effective in trapping MDI in the gas or aerosol phase when tested in the laboratory, but collection efficiencies in the field were low. It seems that MDI produced by polyurethane production processes is not generated as a simple gas or aerosol. Further work is needed to identify the other isocyanate species generated.
American Industrial Hygiene Association Journal, Nov. 1983, Vol.44, No.11, p.802-808. 20 ref.
Innocenti A., Paggiaro P.L.
A case of occupational asthma due to diphenylmethane diisocyanate (MDI)
Un caso di asma professionale da difenilmetano-diisocianato) (MDI) [en italiano]
The case history of a man producing polyurethane shoe soles is presented, together with the results of bronchial provocation tests in which no cross-reaction between MDI and toluene diisocyanate was found.
Medicina del lavoro, Sep.-Oct. 1983, Vol.74, No.5, p.391-393. Illus. 15 ref.
Belin L., Wass U., Audunsson G., Mathiasson L.
Amines: possible causative agents in the development of bronchial hyperreactivity in workers manufacturing polyurethanes from isocyanates
Environmental concentrations of amines and isocyanates and health investigations of 48 workers producing polyurethane foam are reported. They showed increased bronchial reactivity to inhaled methacholine compared with 2 control groups. This and visual disturbances were assumed to be caused mainly by volatile amines. Isocyanate concentrations were well below 0.005ppm, and the amine concentration was 1000-10,000 times higher. N-methylmorpholine was present in concentrations >10ppm. Thus not only isocyanates, but also amines, might be responsible for respiratory symptoms in polyurethane workers.
British Journal of Industrial Medicine, Aug. 1983, Vol.40, No.3, p.251-257. Illus. 44 ref.
White I.R., Stewart J.R., Rycroft R.J.G.
Allergic contact dermatitis from an organic diisocyanate
Allergic contact dermatitis occurring in 6 of 7 women exposed to dicyclohexylmethane 4,4'-diisocyanate used to form a surface-coating polyurethane on car badges is reported. The chief problem was the need to apply resin to part of the badges by hand on account of their particular shape.
Contact Dermatitis, July 1983, Vol.9, No.4, p.300-303. Illus. 4 ref.
Ameille J., Lebeau B., Tisnes J., Orvoen-Frija E., Rochemaure J., Proteau J.
Organic isocyanates and hypersensitivity pneumopathies
Isocyanates organiques et pneumopathies d'hypersensibilité [en francés]
Case study of hypersensitivity pneumopathy due to inhalation of hexamethylene diisocyanate by a garage employee occasionally engaged in spray painting. Symptoms, radiological observations, and results of bronchial lavage and respiratory function tests are compared with data in the literature. The scarcity of reports on this response to isocyanates probably causes the true incidence to be underestimated. Greater awareness of the hazard should promote preventive measures.
Archives des maladies professionnelles, 1983, Vol.44, No.7, p.477-481. Illus. 28 ref.
Beving H., Malmgren R., Olsson P., Tornling G., Unge G.
Increased uptake of serotonin in platelets from car painters occupationally exposed to mixtures of solvents and organic isocyanates
12 car painters and a control group of 50 non-exposed subjects were studied. The mean platelet count in the exposed workers was markedly lower, and 3 had values below the 95% tolerance interval limit of the controls. In 9 workers the serotonin uptake rates were significantly elevated. The method can be used to reveal early organ damage before appearance of clinical symptoms.
Scandinavian Journal of Work, Environment and Health, June 1983, Vol.9, No.3, p.253-258. Illus. 30 ref.
Methods of sampling and analysis of amines and isocyanates
Provtagnings- och analysmetoder för aminer och isocyanater [en sueco]
Methods of sampling and analysis of these substances are surveyed, for purposes of coordinating research: analytical methods for isocyanates (colorimetry, liquid-liquid chromatography, thin-layer chromatography, gas chromatography - by electron-capture detection or by N,P detector, continuous analytical methods: filter tape, photoacoustic spectroscopy, Fourier-transform spectroscopy); analytical methods for amines (liquid-liquid chromatography, infrared spectrophotometry, isotachophoresis, gas chromatography, derivative-detection methods); sampling methods for isocyanates (adsorption, chemosorption, sorbent-free sampling) and for amines (absorption, chemosorption, adsorption). Suggestions for a plan of action during analysis. Description of the sampling method recommended by the Swedish OSH authorities in 1980. Current research projects are listed.
Arbetarskyddsfonden, Box 1122, 111 81 Stockholm, Sweden, Apr. 1983. 39p. Illus. 2 ref.
Silk S.J., Hardy H.L.
Control limits for isocyanates
The UK Health and Safety Commission has introduced (effective 1 Feb. 1983) a unified 2-part control limit for exposure to isocyanates (2,4 and 2,6-toluene diisocyanate (TDI), methylene 4,4'-diphenyl diisocyanate (MDI), and related compounds such as hexamethylene-1,6 diisocyanate (HDI). The limits are an 8h TWA of 20µg NCO/m3 (0.005ppm) and a 10min TWA of 70µg NCO/m3 (0.02ppm) for the 3 compounds given. The development of exposure limits to these compounds are outlined and the calculation of the standards for the aliphatic prepolymer are explained.
Annals of Occupational Hygiene, 1983, Vol.27, No.4, p.333-339. Illus. 13 ref.
Bishop R.W., Ayers T.A., Esposito G.G.
A gas chromatographic procedure for the determination of airborne MDI and TDI
Diphenylmethane diisocyanate (MDI) and toluene diisocyanate (TDI) are collected in midget impingers containing 10cm3 of absorbing solution (3.5% HCl + 2.2% acetic acid in H2O). Total sampling volumes between 20 and 60l at 1l/min are recommended. The hydrolysed diisocyanates are converted to free diamines with caustic and extracted into toluene. The diamines are then derivatised with heptafluorobutyric anhydride, and the derivatives are analysed by gas-liquid chromatography using an electron-capture detector. The method is specific for the 2 diisocyanates; recoveries and coefficients of variation are respectively 102% and 3.8% for MDI and 70% and 4.3% for TDI. Detection limits in air for a 40l sample are 5µg/m3 for MDI and 3.5µg/m3 for TDI.
American Industrial Hygiene Association Journal, Mar. 1983, Vol.44, No.3, p.151-155. Illus. 13 ref.
L'asthme aux isocyanates [en francés]
Contents of this M.D thesis: (I) review of bronchial asthma: definition, physiopathology, clinical picture, differential diagnosis, respiratory function tests, treatment; (II) isocyanates: characteristics, identification, methods of determination in air, polyurethanes made from isocyanates; (III) pulmonary pathology due to isocyanates as illustrated by 9 case studies: symptomatology, action mechanism of the isocyanates, detection and progress of the disease, prevention (legal aspects, medical supervision, individual and collective protection).
Université Paris VII, Faculté de médecine Xavier-Bichat, Paris, France, 1983. 105p. 23 ref.
Andersson K., Gudéhn A., Hallgren C., Levin J.O., Nilsson C.A.
Sampling and analysis of organic substances on the threshold limit values list - XII. Chemisorption of gaseous diisocyanates
Provtagning och analys av organiska ämnen på gränsvärdeslistan - XII. Kemosorption av gasformiga diisocyanater [en sueco]
Contents of this research report: evaluation of different methods used for the sampling and analysis of diisocyanatges; results showing the efficiency of desorption of different diisocyanates sampled by chemisorption; solvents, chemicals and solutions used; analytical technique; chemisorption and desorption technique; reproductions of chromatograms; descriptions of specific methods for hexamethylene, diphenylmethane, and tolylene diisocyanates.
Arbetarskyddsstyrelsen, Publikationsservice, 171 84 Solna, Sweden, 1983. 11p. Illus. 10 ref.
Experimental studies of the biological effects of TDI - An inhalation study in skin-sensitised mice
An investigation of the biological effects of tolylene diisocyanate (TDI), used in the polyurethane industry. Allergic dermatitis was developed in mice by sensitisation to TDI, following which the mice were exposed to TDI vapour to see if a delayed type allergy plays a role in lung disorders caused by TDI. At a concentration of 0.6ppm, inhaled for 2h, allergic dermatitis did develop, but without noticeable pathological change in the respiratory organs.
Journal of Tokyo Women's Medical College, Mar. 1983, Vol.53, No.3, p.237-246. Illus. 30 ref.
Decree No.83-71 of 2 Feb. 1983 to amend and complement the occupational disease schedules attached to Decree No.46-2959 of 31 Dec. 1946
Décret n°83-71 du 2 février 1983 révisant et complétant les tableaux de maladies professionnelles annexés au décret n°46-2959 du 31 déc. 1946 [en francés]
Two new schedules have been added: No.72 relates to diseases caused by exposure to nitrate derivatives of glycol and glycerol; No.73 to occupational diseases caused by antimony and its compounds. Modifications were made to: schedule No.2 (mercury and compounds); No.31 (aminoglycosides); No.32 (fluorine, hydrogen fluoride and its mineral salts); No.33 (beryllium and compounds); No.52 (diseases due to vinyl chloride polymerisation processes); No.62 (organic isocyanates); No.65 (eczematous lesions with an allergic mechanism of action).
Journal officiel de la République française, 6 Feb. 1983, p.495-499.
Metyyli-isosyaniitti [en finlandés]
Methyl isocyanate is a toxic liquid (LD50 = 71mg/kg; TLV = 0.05mg/m3). The liquid severely irritates and corrodes the skin and the eyes, and it can cause eczema. The vapour irritates the respiratory tract and the eyes and it causes pulmonary oedema at high concentrations. Reactive with water. Forms toxic nitric oxides at high temperatures. Mandatory European labelling: F, T, R12, R23, R24, R25, R36, R37, R38, R101, S9, S30, S43, S44, S101.
Register of Safety Information of Chemical Products, National Board of Labour Protection, Box 536, 33101 Tampere, Finland, May 1982. 2p. Original on microfiche.
Amines and isocyanates in the workplace - Research needs as regards analysis and sampling
Aminer och isocyanater i arbetslivet - FoU-behov av analys och provtagning [en sueco]
Proceedings of a seminar (Lund, Sweden, 25-26 Aug. 1982), dealing with the topics: industrial uses of amines and isocyanates; rules for their proper handling; health hazards; amines and skin diseases; sampling and analysis (isocyanate determination in air using liquid chromatography and gas chromatography with electron capture; gas chromatography with mercury-phosphorus detection; isotachophoresis; sampling and analysis of TDI on filter tape; photoacoustic and Fourier-transform spectroscopy; sampling methods); special problems of the polyurethane, paint, varnish, rubber and epoxy resin industries.
Arbetarskyddsfonden, Box 1122, 111 81 Stockholm, Sweden, Nov. 1982. 102p. Illus. 62 ref.
Vigueira Rubio J.
Determinación de TDI en aire en presencia de MDI por espectrofotometría de doble longitud de onda
The method is described. The wavelengths used are 540.5 and 580nm. The differences in absorbance read directly by the spectrophotometer between the 2 wavelengths allow determination of the TDI concentration without interference by the presence of MDI. The limit of detection of TDI is 0.05mg/m3 in 20l air.
Medicina y seguridad del trabajo, July-Sep. 1982, Vol.30, No.119, p.172-176. Illus. 8 ref.
Šaronova Z.V., Penkovič A.A., Dorofeeva E.D., Kryžanovskaja N.A., Mel'nikova N.D., Volkova I.D., Golova I.A, Arzjaeva E.Ja., Klimova Ė.I., Maze Ė.N.
Cardiovascular changes in workers in tolylene diisocyanate production
Izmenenija serdečno-sosudistoj systemy u rabočih proizvodstva toluilendiizocianata [en ruso]
The cardiovascular function of 92 workers in an old tolylene diisocyanate (TDI) plant was compared with that of 148 workers in a more modern plant producing a number of isocyanates. Workers in the older plant, where TDI concentrations were commonly 0.1-0.5mg/m3, had higher frequencies of head and chest pain, arterial hypertension and ischaemic heart disease that did workers in the newer plant, with TDI concentrations of 0.021-0.031mg/m3 (the MAC for TDI is 0.05mg/m3). Abnormalities in the ventricular complex of electrocardiograms were also more frequently encountered in workers from the older plant. The frequency and severity of complaints was correlated with length of service in contact with TDI.
Gigiena truda i professional'nye zabolevanija, Jan. 1982, No.1, p.16-19. 6 ref.
Liquid chromatographic determination of dimethylformamide, methylenebisphenyl isocyanate and methylenebisphenylamine in air samples
For sampling of the mixture, silica gel coated with diethylamine was used. Since isocyanate is highly reactive, it must be rapidly converted into a stable derivative. This was achieved by reaction with diethylamine. After desorption of the mixture, compounds are separated by high-performance liquid chromatography. Spectrophotometric detection was used for determination of the mixture components.
Annals of Occupational Hygiene, 1982, Vol.25, No.1, p.1-4. Illus. 15 ref.
Australian TDI workers' sera assayed for IgE against a p-tolyl-isocyanate-human serum albumin conjugate
The sera of 20 blood donors, 70 factory workers, and 1 casualty patient were assayed for IgE which bound to a p-tolyl-isocyanate-human serum albumin conjugate. 3 factory workers had abnormally high assay values in association with active tolylene diisocyanate (TDI) disease, as indicated by asthma or measurement showing chronic airway obstruction. One factory worker had an exceptionally high assay value without clinical evidence of TDI disease. Hapten inhibition studies indicated possible heterogeneity of the IgE detected by the assay. Clinical histories suggest that TDI disease can include susceptibility to asthma triggered by events other than TDI exposure.
American Industrial Hygiene Association Journal, Oct. 1982, Vol.43, No.10, p.759-763. Illus. 12 ref.
Diem J.E., Jones R.N., Hendrick D.J., Glindmeyer H.W., Dharmarajan V., Butcher B.T., Salvaggio J.E., Weill H.
Five-year longitudinal study of workers employed in a new toluene diisocyanate manufacturing plant
Respiratory health of 277 TDI workers was studied prospectively. Peak and 8h TWA concentrations were determined in over 200 samples. Smoking had a significant effect on spirometric tests and lung volumes. After adjustment for smoking, the 74 men in the high TDI exposure group had significantly larger declines in FEV1, %FEV and FEF25-75 than the 149 men in the low exposure category. Annual change in FEV1 is analysed in 6 smoking/exposure categories. The results support the NIOSH standard 8h TWA of 5ppb TDI.
American Review of Respiratory Disease, Sep. 1982, Vol.126, No.3, p.420-428. 21 ref.
Exposure to isocyanates in six polyurethane-processing industries
Exposition för isocyanater vid sex polyuretantillverkande industrier [en sueco]
Contents of this industrial-hygienist examination paper: uses of tolylene diisocyanates (TDI), diphenylmethane diisocyanate and phenyl isocyanate, their effects on health and occupational health problems involved; processing techniques (casting of polyurethane, block foaming); measuring equipment and methods of analysis used for this industrial hygiene survey; sampling with the aid of personal and stationary samplers; ventilation systems in the casting and foaming shops visited; reproduction and discussion of results: whereas the average exposure to isocyanates during casting was below the TLV of 0.01ppm under normal operating conditions, block foaming may give rise to exposures exceeding by far 0.01ppm of TDI.
Arbetarskyddsstyrelsen, Publikationservice, 171 84 Solna, Sweden, 1982. 39p. 14 ref.
Criteria Group for Occupational Standards (Sweden)
Scientific basis for Swedish occupational standards II
A collection of consensus reports which bring together and evaluate the relevant scientific data on substances which may present an occupational health risk; these consensus reports are intended for use as background material by the Swedish National Board of Occupational Safety and Health in the preparation of its occupational standards (exposure limits). Substances considered are: chlorine and chlorine dioxide; inorganic arsenic (excluding arsenic hydride); benzene; synthetic inorganic fibres; 1,1,1-trichloroethane; diisocyanates; oil mist; wood dust.
Arbetarskyddsstyrelsen, Publikationsservice, 171 84 solna, Sweden, 1982. 97p. Illus. 160 ref.
Musk A.W., Peters J.M., Di Berardinis L., Murphy R.L.H.
Absence of respiratory effects in subjects exposed to low concentrations of TDI and MDI
Report of a 5-year follow-up study of 107 workers in a polyurethane manufacturing plant using FEV1 measurements and questionnaires on respiratory symptoms and smoking habits. Toluene diisocyanate and diphenylmethane diisocyanate exposure levels were monitored. Mean FEV1 was higher than that predicted for healthy subjects and the 5-year change in FEV1 did not exceed that expected from ageing. No acute change in FEV1 was observed on a Monday either before or after a 2-week vacation and no ventilary function improvement was observed during vacation. Low-level isocyanate exposure (time-weighted average concentrations around 0.001ppm) is not associated with chronic respiratory symptoms or effects on ventilatory capacity.
Journal of Occupational Medicine, Oct. 1982, Vol.24, No.10, p.746-750. 23 ref.
Rosenberg C., Pfäffli P.
A comparison of methods for the determination of diphenylmethane diisocyanate (MDI) in air samples
High-performance liquid chromatography (HPLC), colorimetric, and continuous tape monitoring methods were compared in the determination of concentrations of MDI in the air of 2 different industrial environments and a laboratory exposure chamber. Neither the colorimetric nor the tape monitoring methods were sensitive enough to determine concentrations of MDI < 0.2 x 10-2 and < 1 x 10-2mg/m3 respectively. Determinations made with the HPLC method at different rates of sampling yielded similar results on simultaneous sampling even at concentration levels of 0.2 x 10-2mg/m3, indicating that this method is useful for both sampling and analysis. The volumes during sampling were in the 5-150l range. The flow rate chosen was 2.5-3.0l/min. The concentration of MDI in the atmospheres of the workplaces was below the current threshold limit value of 0.2mg/m3.
American Industrial Hygiene Association Journal, Mar. 1982, Vol.43, No.3, p.160-163. 16 ref.
Malo J.L., Zeiss C.R.
Occupational hypersensitivity pneumonitis after exposure to diphenylmethane diisocyanate
A foundry worker developed dyspnoea and a restrictive breathing defect after exposure to diphenylmethane diisocyanate (MDI). His symptoms and lung function impairment subsided after he left foundry work. Specific inhalation challenges with MDI induced general malaise, a significant increase in body temperature and leukocyte count, and a decrease in forced vital capacity and transfer factor. Total antibody activity to a MDI human serum albumin conjugate was detected by ammonium sulfate precipitation and specific IgG antibodies were demonstrated by the enzyme-linked immunoabsorbent technique.
American Review of Respiratory Disease, Jan. 1982, Vol.125, No.1, p.113-116. Illus. 29 ref.
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