Controlled dynamic generation of standard 1,6-hexamethylene diisocyanate aerosols

A procedure for the dynamic generation of 1,6-hexamethylene diisocyanate (HDI) aerosol atmospheres of 70 micrograms m-3 (0.01 ppm) to 1.75 mg m-3 (0.25 ppm), based on the precise control of the evaporation of pure liquid HDI and subsequent dilution with air, was developed. The apparatus consisted of a home-made glass nebulizer coupled with a separation stage to exclude non-respirable droplets (greater than 10 microns). The aerosol concentrations were achieved by passing air through the nebulizer at 1.5-4.5 l. min-1 to generate dynamically 0.01-0.25 ppm of diisocyanate in an experimental chamber of 8.55 m3. The distribution of the liquid aerosol was established with an optical counter and the diisocyanate concentration was determined from samples collected in impingers by a high-pressure liquid chromatographic method. The atmospheres generated were suitable for the evaluation both of sampling procedures full scale, and of analytical methods: at 140 micrograms m-3 (0.02 ppm) they remained stable for 15-min provocation tests in clinical asthma, as verified by breath-zone sampling of exposed patients.

Footnotes, June, July, August 2006, Vol. 31, no. 6-7-8

Monthly newsletter of the State Library

Hki 19/6 1945

Kirje 19.6.1945

M. Tullius Cicero, Somnium Scipionis (2-5v). - Macrobius, Commentarius in somnium Scipionis (6-77v).

Les ff. 78-87v, en papier, contiennent des notes mss. sur l'ouvrage de Macrobe, du XVIIe s."

Professori V. Merikoski 12/6 1966

Kirje

Professori L.E. Taxell 5/6 1960

Kirje 5.6.1960

Kansanedustaja Pekka Vilmi 9/6 1964

Kirje 9.6.1964

Motor Vehicle Accident Fatalities for the Week Ending, October 6, 2006

Record of the Fatalities for Motor Vehicle Accidents in Iowa per week.

EPI Update, October 6, 2006

Weekly newsletter for Center For Acute Disease Epidemiology of Iowa Department of Public Health.

Rouva Eva Paloheimo 10/6 1969

Kirje 10.6.1969

Mikkeli 6.8.1924

Kirje