Document RpxE4jmpkM0KyKnDMyEDVdYdX

- . Pure iron carbonyl was applied to- the abdominal ' .' v; [. skin of rabbits* .after carefully lipping off the hair or fur ' without injury to the skin and without wetting it. The animals were effectively restrained on animal boards and put in a fume bood with their heads turned Into the air-stream so as to avoid inhalation of the volatilising liquid applied on the skin. The volatility of iron carbonyl is such that the pure compound ap- plied to the skin of the rabbit disappears as such In from 5 to 15 minutes leaving the skin somewhat red and apparently dry., ; ; %he smoky odor of iron carbonyl ban be detected on the skin for some period after the apparent disappearance of the liquid. . The following results were oheenrea: 1. ;2 ooV applied in one dose caused death of the rabbit In 36 hours. 2. 10 Co. applied in one dose caused death of the rabbit in hours. > : 3 -20ecr*^applied,' in two doses of 10 oc, each,with an Interval of 30 minutes^paused death in 12 hours. v; , :- ;^rr*;:. , Pure iron carbonyl waslnjeoted subcutaneously with `Ji o ro 0C0O o o o Ui Pur iron carbonyl was administered to a rabbit orally in a dose of 1 oo. ' The animal died in li$ hours* Each of several rabbits was exposed to air containing iron carbonyl in a small cage into which an air stream containing Iron carbonyl was introduced at a rate of 4- liters per minute, the .concentration of iron-Carbonyl in the air was determined by in direct means and may be somewhat, although not grossly, in error* , The following results were obtained. t . 1. A rabbit exposed for K minutes to air containing ; approximately 400 milligrams of iron carbonyl per liter of air / , aied 12 hours later: , - 2. Another rabbit exposed for 2 hours to 20 mg. Fe (CO)^ /per liter of air died in 12 hours. . 3* Another exposed for 1 hour to 10 mg. Fe (CO)e; per liter of air died 17 hours later. if. Another exposed for 1 hour to 7.5 mg. Fe (00)^ per liter of air died in 12 hours. ' 5 Another exposed for 1 hour to 2.5 rag, Fe (CO)^ per liter died in k l hours. 6. Another exposed for 1 hour to 1.0 mg. Fe (CO)^ per liter died in 40 hours. The effects of iron oarbonyl on rabbits was essentially the same regardless of the mode of administration although the KE 0003331 animal hilled by oral administration showed gastro-lntestinal irritation in addition to the characteristic lesions elsewhere. These characteristics, however, were a striking degree of edema and acute congestion of the lungs, with occasional petechia! hemorrhages : acute dilltation of the heart, and acute toxic changes- tract, except in the instance of the administration of the material by mouth was almost entirely normal. As opposed to expectations based on statements that the carbonyls are toxic because of the release of carbon monoxide into the blood, the blood of siclc and dead animals at no time contained carboxyhemaglobln in sufficient quantities to be revealed by the tannic-pyrogallic acid method of testing. It is apparent, therefore, that the toxicity of the material la not due to the production of carbon monoxide through a molecular decomposition in the tissues. As a matter of fact such a decomposition, although it probably occurs, does so quite slowly. Material Injected sub** cutaneously was often found undeeomposed and partly unabsorbed at the site of injection. Animals treated with toxic amounts of the material always-showed the same striking symptoms. Sapid and labored respiration developed and the animal sat with the head sharply retracted, the nose pointing upward (opisthotonus), there was no diarrhoea, and in only one instance, in which an animal was , exposed to air saturated with iron-carbonyl, were convulsions seen. K 0003332 Comment (Hot for quotation) T h e r e Is some slight evidence that iron-carbonyl Is more toxic for rabbits than for other animals, cats for example. However experimental data here are quite fragmentary. From the experience of persons outside the United States, who have handled considerable quantities of the material, to reduce their toxicity. It is possible that the finely divided vapors decompose rapidly when distributed in the air itt the presence of light, this* however, has not been established and can not be used as a basis for a belief that the material is less dangerous than is indicated by the above data, In any case the available heresay reports as to the occupational handling of , the compound are believed to be unreliable. The writer is of the opinion that cases of acute<poisoning and death have occurred , . among men who have been exposed to high concentrations of the vapor in the manufacture-and handling of iron-carbonyl for commercial purposes. Apparently, however, measures for avoiding serious exposure were found to be feasible* It is doubtful if there is any cumulative toxic effect from the absorption of sUb-lethal doses, although there is no published evidence on this point* Hobert A. Kehoe, Director Kettering Laboratory of Applied Physiology College of Medicine University of Cincinnati Kg0 0 C3333