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1323. Respiratory effects from diazomethane
438
THE CHEMICALENVIRONMENT
varied from 0.2 ppm for Freon-253 to 3470 ppm for Freon-12. The recommended MAC values for these compounds range from 0.003 ppm for Freon-253 to 20 ppm for Freon-12, based on the two values for average lethal dose and minimum effective concentration for central nervous effects. 1321. A versatile surfaetant
Miyauchi, Y., Inoue, T. & Paton, B. C. (1966). Adjunctive use of a surface-active agent in extracorporeal circulation. Circulation 33/34, suppl. 1, p. 71. During extracorporeal circulation, damage to red cells and other blood elements is associated with contact with gas in the oxygenator. The addition of 0.6 mg/ml of the surfactant, Pluronic F68 (I), to the priming solution reduced haemolysis and fat embolism in dogs and in 13 patients given protracted perfusions. I also caused a decrease in intravascular sludging and reduced the deposition of fibrin on the filter of the oxygenator. It caused no significant alteration in flow rate, urinary output, acid-base metabolism, electrolyte changes or chest drainage. I is a non-ionic polyol surfactant of molecular weight 8200. It has shown extremely low toxicity in intravenous and chronic oral tests and has been used for stabilizing fat emulsions for intravenous use. 1322. TDI in dust
Freeborn, A. S. (1965). Unreacted isocyanate groups in cured polyurethane lacquers. J. Oil Colour Chem. Ass. 48, 539. The well-known hazards of toluene diisocyanate (TDI) (Cited in F.C.T. 1965, 3, 644) have now been largely overcome in industry by the use of less volatile TDI conjugates, but a potential danger still exists if dust arising from sanded polyurethane (PU) lacquers contains unreacted isocyanate groups. The Kubitz method using malachite green (I) and butylamine (II) was found suitable for detecting such unreacted groups in cured PU films. Addition of II to a solution of the oxalate salt of I reduces the optical density of the solution, and II also reacts with isocyanate groups. Ira standard amount of II is shaken with a sample of PU film, therefore, the decrease in its capacity for reducing the optical density of a solution of I is a measure of the free isocyanate groups present in the PU. The method may give a somewhat low result owing to incomplete reaction between II and the free lsocyanate and to possible extraction from the film of other amines which could react with I. Using this technique, a small amount of free isocyanate (0.41 ~o in the example quoted) has been demonstrated in abraded dust, and the widely held supposition that this small isocyanate content of dust is immediately removed by moisture in the surrounding air has been shown to be incorrect. 1323. Respiratory effects from diazomethane
Vysko[il, J., Sklensk)), B. & Dluho~, M. (1966). Experimentfilni studie toxick6ho 6~inku diazometanu. "Experimental study on toxic effect of diazomethane." Pracovni IAk. 18, 10. Diazomethane (I) is probably best known to our readers for the postulated role it plays in nitrosamine carcinogenesis (Cited in F.C.T. 1966, 4, 530). The present report is, however, concerned with inhalation effects of I. Clinical findings following accidental human exposure to very high concentrations of I have suggested that it may cause severe irritation of the respiratory tract and pulmonary oedema (Le Winn, Am. J. reed. Sci. 1949, 218, 556). Work in rabbits has now confirmed this view. Rabbits exposed 1-4 times at weekly intervals to atmospheric concentrations of 2-12 ppm I for 5-20 min developed acute inflammation of the trachea, bronchi and bronchioles, followed by severe emphysema.
THE CHEMICALENVIRONMENT
varied from 0.2 ppm for Freon-253 to 3470 ppm for Freon-12. The recommended MAC values for these compounds range from 0.003 ppm for Freon-253 to 20 ppm for Freon-12, based on the two values for average lethal dose and minimum effective concentration for central nervous effects. 1321. A versatile surfaetant
Miyauchi, Y., Inoue, T. & Paton, B. C. (1966). Adjunctive use of a surface-active agent in extracorporeal circulation. Circulation 33/34, suppl. 1, p. 71. During extracorporeal circulation, damage to red cells and other blood elements is associated with contact with gas in the oxygenator. The addition of 0.6 mg/ml of the surfactant, Pluronic F68 (I), to the priming solution reduced haemolysis and fat embolism in dogs and in 13 patients given protracted perfusions. I also caused a decrease in intravascular sludging and reduced the deposition of fibrin on the filter of the oxygenator. It caused no significant alteration in flow rate, urinary output, acid-base metabolism, electrolyte changes or chest drainage. I is a non-ionic polyol surfactant of molecular weight 8200. It has shown extremely low toxicity in intravenous and chronic oral tests and has been used for stabilizing fat emulsions for intravenous use. 1322. TDI in dust
Freeborn, A. S. (1965). Unreacted isocyanate groups in cured polyurethane lacquers. J. Oil Colour Chem. Ass. 48, 539. The well-known hazards of toluene diisocyanate (TDI) (Cited in F.C.T. 1965, 3, 644) have now been largely overcome in industry by the use of less volatile TDI conjugates, but a potential danger still exists if dust arising from sanded polyurethane (PU) lacquers contains unreacted isocyanate groups. The Kubitz method using malachite green (I) and butylamine (II) was found suitable for detecting such unreacted groups in cured PU films. Addition of II to a solution of the oxalate salt of I reduces the optical density of the solution, and II also reacts with isocyanate groups. Ira standard amount of II is shaken with a sample of PU film, therefore, the decrease in its capacity for reducing the optical density of a solution of I is a measure of the free isocyanate groups present in the PU. The method may give a somewhat low result owing to incomplete reaction between II and the free lsocyanate and to possible extraction from the film of other amines which could react with I. Using this technique, a small amount of free isocyanate (0.41 ~o in the example quoted) has been demonstrated in abraded dust, and the widely held supposition that this small isocyanate content of dust is immediately removed by moisture in the surrounding air has been shown to be incorrect. 1323. Respiratory effects from diazomethane
Vysko[il, J., Sklensk)), B. & Dluho~, M. (1966). Experimentfilni studie toxick6ho 6~inku diazometanu. "Experimental study on toxic effect of diazomethane." Pracovni IAk. 18, 10. Diazomethane (I) is probably best known to our readers for the postulated role it plays in nitrosamine carcinogenesis (Cited in F.C.T. 1966, 4, 530). The present report is, however, concerned with inhalation effects of I. Clinical findings following accidental human exposure to very high concentrations of I have suggested that it may cause severe irritation of the respiratory tract and pulmonary oedema (Le Winn, Am. J. reed. Sci. 1949, 218, 556). Work in rabbits has now confirmed this view. Rabbits exposed 1-4 times at weekly intervals to atmospheric concentrations of 2-12 ppm I for 5-20 min developed acute inflammation of the trachea, bronchi and bronchioles, followed by severe emphysema.