UNITED STATES DEPARTMENT OF AGRICULTURE 



jfvy^-rt. 



Joint Contribution from the Bureau of Plant Industry 



WM. A. TAYLOR, Chief, and the Bureau of 



Chemistry, CARL L. ALSBERG, Chief 



Washington, D„ C. 



PROFESSIONAL PAPER 



August 8, 1917 



THE PRESENCE OF ARSENIC IN HOPS. 



By W. W. Stockbbrgbr, Physiologist in Charge of Drug-Plant and Poisonous-Plant 

 Investigations, Bureau of Plant Industry, and W. D. Collins, Food- Investigation 

 Chemist, Bureau of Chemistry. 



Situation with respect to arsenic in hops . 

 Collection of materials for examination. . . 

 Analysis of materials 



CONTENTS. 

 Page. 



Results of analyses. 

 Conclusions 



Page. 

 3 



7 



SITUATION WITH RESPECT TO ARSENIC IN HOPS. 



At times the detection of minute traces of arsenic in shipments of 

 American hops exported to foreign countries has led to their rejection 

 by prospective purchasers. The loss sustained in such cases is 

 borne by the exporter; consequently American growers, who sell as a 

 rule to local buyers only, do not realize fully the extent to which the 

 salability of American hops on foreign markets may be affected 

 unfavorably by an occasional contaminated shipment. 



The profitableness of hop production in the United States is deter- 

 mined practically by the extent of the foreign demand for the crop 

 surplus in excess of the requirements for domestic consumption. 

 Any impairment of the quality of American hops, whether definitely 

 proved or only suspected by foreign consumers, lessens the chances 

 for marketing the surplus at reasonable prices and eventually reacts 

 upon the grower in a lower price for his product. Although the 

 probability of any damage to the public health from arsenic com- 

 municated by hops to ale or beer seems very remote, nevertheless the 

 minute quantity of arsenic permissible in hops under some foreign 

 standards of purity lays the grower under obligation to use every 

 reasonable precaution to avoid all possible sources of contamination. 



In a bulletin published in 1908 by the Bureau of Plant Industry, 1 

 impure sulphur was suggested as the source of the traces of arsenic 



1 Stockberger, W. W. The sources of arsenic in certain samples of dried hops. In U. 8. Dept. Agr., 

 Bur. Plant Indus. Bui. 121, p. 41-46. 1908. 

 101097°— Bull. 568—17 



