﻿ABSORPTION OF HYDROCYANIC ACID. 16 



SUMMARY. 



Hydrocyanic acid gas, widely used as a fumigant against certain 

 insects and rats, often comes in contact with materials intended for 

 food. The quantity of hydrocyanic acid absorbed and retained by vari- 

 ous fumigated foodstuffs has been determined. 



All of the products examined absorbed the fumigant to some ex- 

 tent. Hard rinds of vegetables or skins of fruits had a tendency to 

 decrease the absorption. Chlorophyll-bearing vegetables, or those 

 of a succulent nature, in general, took up large quantities of hydro- 

 cyanic acid. 



Some of the fruits and vegetables suffered physical injury (wilting, 

 softening, or discoloration) because of fumigation to such an extent 

 that they were unmarketable. 



In the case of the seeds most of the hydrocyanic acid was rapidly 

 dissipated, so that by the fourth day the content usually was not 

 more than 5 parts per million. After this there was a slow dissipa- 

 tion, a very small quantity of the fumigant being present at the end 

 of three months. The flour examined absorbed a large quantity of 

 hydrocyanic acid but gave it off so rapidly that by the end of four 

 days, or, at the most, a week, no traces of it could be detected. 



Evacuating the chamber after fumigation was not effective in 

 removing absorbed hydrocyanic acid. 



The concentration of hydrocyanic acid gas used had, in general, a 

 marked effect on the quantity absorbed by the product. This was 

 noticeable even at the end of three months. 



The quantities of hydrocyanic acid absorbed by various other 

 products were determined also. 



No conclusions as to the safety of fumigated foods for consumption 

 are drawn in this bulletin. Chemical observations alone are included. 

 Determinations of the quantities of hydrocyanic acid injurious to 

 human health lie in the domain of the pharmacologist. 



BIBLIOGRAPHY. 



1) Anonymous. 



Adsorption of cyanide gas by foodstuffs. In U. S. Public Health Ser., 

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2) Bail, Oskar. 



Ungeziefervertilgung mittels Blausauregas. In Gesundh. Ing. (1919), 



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Ungezieferbekampfung mit Blausauredampfen. In Centr. Bakt. Parasitenk. 



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4) Bell, J. T. 



How to destroy cabinet pests. In Can. Entomol. (1877), 9:139-40. 



5) Corlette, C. E. 



Insecticidal fumigation in ships, with special reference to the use of hydro- 

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6) Creel, R. H., Faget, F. M., and Wrightson, W. D. 



Hydrocyanic acid gas. Its practical use as a routine fumigant. In U. S. 

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Insect control in flour mills. In Am. Miller (1922). 50:752-3. 



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Effect of common mill fumigants on the baking qualities of wheat flour. In 

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