Nov. 1,1925 
Benzene as a Larviddefor Screw Worms 
887 
TOXICITY OF BENZENE TO ANIMALS 
No tests have been made to determine the toxicity of benzene to 
the higher animals except in its practical use as a larvicide for the 
screw worm. No toxic effect has been observed on sheep and goats 
where the wool and mohair were entirely saturated on all parts of the 
body, and wounds as large as 8 inches in diameter were treated with 
sufficient amounts to kill all larvae in them. Such animals have in all 
cases been healed when they were kept under observation, although 
in some instances they were down and unable to move when treat¬ 
ment was begun. Goats, sheep, and calves quite commonly have 
infestations of worms in the mouth to the extent that all of the 
teeth are lost. In treating these cases care has been used to prevent 
the animals from swallowing any of the benzene and it is applied in 
small amounts (2 to 5 c. c.). In no case has any ill effect on the ani¬ 
mals been observed. 
In the treatment of more than 3,000 cases of worms in cattle, sheep, 
goats, hogs, dogs, and chickens, there has never been any noticeable 
toxic effect on the animal. In the work on the range it has been 
remarkable and significant to note the number of animals reported 
“as good as dead* 5 by the herders that recovered completely after 
treatment. Most ranchmen have had the idea that any serious 
infestation with screw worms would kill the animal and for this reason 
many animals badly infested with worms have been killed and 
burned. In 2,843 cases of infested animals treated with benzene 
under the writer’s personal observation, only 5 have died. In 3 of 
these cases the worms had entered the body cavity or were present 
in the head of the animal and had affected the nervous system. 
Holland 2 makes the following statement: “A narcotic effect is 
P roduced by accidental inhalation of benzene vapor in factories. 
Ine ounce (30 c. c.) taken by the stomach caused death after symp¬ 
toms such as headache, giddiness, bluish flush of the face, delirium, 
convulsions, and coma.” While a wound in a big steer was being 
treated a pint bottle was kicked by the steer ana broken and the 
contents thrown into the writer’s face. There was some difficulty 
in breathing for about two minutes. The excess was wiped away 
and the face and eyes had a numb, cool feeling for about five minutes; 
there was then a slight burning sensation in the eyes which lasted 
about ten or fifteen minutes, succeeded by a very pleasant, clean, 
sensation in the eyes. No other symptoms were noticed at the time 
or later. When benzene is spilled on clothing and penetrates to the 
skin there is a burning sensation, but to the writer’s knowledge no 
injury has ever been observed. 
BENZENE IN PRACTICAL USE 
Besides the experimental work in which benzene has been used, 
approximately 5,000 animals or more have been treated by ranchmen 
and herdsmen. The benzene was furnished by the Bureau of Ento¬ 
mology and reports were made to the bureau. Fifty-three ranchmen 
have Been furnished benzene in amounts of 1 pint to 1 gallon each. 
Reports have been received from all of these and some were quite 
* Holland, J. W. a text-book of medical chemistry and toxicology. Ed. 5, rev., 683 p., illus. 
Philadelphia and London. 1917. 
