Ideas
Exchange
Column
l/EC's features bring in lots o f f a n mail. Readers w a n t information, and they pass along ideas. Column is a careful screening of this correspondence. This is not a place for praise or criticism; technical questions and their factual answers.
High-Energy Fuel Elements DEAR SIR:
I would like to bring to your at tention w h a t appears to me to be a conflict in views. M r . Weilmuenster in his article, "Utilization of HighEnergy Fuel Elements," ( I / E C , p. 1337, P a r t I, September 1957) makes this statement concerning boranes: " T h e materials have been produced in test quantities a n d have lived u p to expectations of high den sity, low toxicity, a n d safe handling, in addition to a high-energy con tent." I n the Industrial Hygiene section ( I / E C , p . 87 A, Part I, September 1957), this statement concerning the toxicity of diboranes a p p e a r s : " I n s u m m a r y , it can be stated t h a t diborane, p e n t a b o r a n e , a n d decabor ane are highly toxic c o m p o u n d s a n d a d e q u a t e control measures must be instituted to prevent serious hazards to h e a l t h . " I would appreciate it if you would resolve this a p p a r e n t contradiction. W . B. H A R D I N G
Materials Engineer Bendix Aviation Corp. Kansas City Division Kansas City 4 1 , M o . E d i t o r ' s N o t e : T h e editors have contacted the authors of b o t h of these articles and their answers are given here. Mr. Weilmuenster's
Answer:
I n the article, "Utilization of HighEnergy Fuel Elements," the state m e n t in question regarding the low toxicity of high energy fuels defi nitely did not refer to the boron hy drides, but rather to new boron-con taining high energy materials, such as H E F - 2 a n d H E F - 3 . Because of security regulations the exact composition of these new fuels cannot be disclosed. T h e r e is n o question whatever t h a t diborane, p e n t a b o r a n e , a n d decaborane are very toxic com
pounds. However, we will stand by our statement that the high energy fuels ( H E F ) exhibit low toxicity. Dr. Schrenk's
Answer:
This is in reply to the letter regard ing the toxicity of borane compounds as given in m y Industrial Hygiene column. T h e majority of reports, which have recently been issued on the toxicity of boranes, have origi nated from the G r a d u a t e School of Public H e a l t h of the University of Pittsburgh, a n d the Chemical Corps Medical Laboratories, Army Chem ical Center, M a r y l a n d . T h e arti cle, "Toxicity Tests of Decaborane for Laboratory Animals. IIIChronic I n h a l a t i o n Studies," by J. L. Svirbely and J. C. Roberts, Jr. [Arch. Ind. Health 14, 163 (1956)], presents d a t a on the chronic toxicity of decaborane. T h e d a t a show t h a t repeated exposure to 4.5 p.p.m. decaborane was injurious to rabbits, dogs, monkeys, a n d rats. It is indi cated t h a t safe concentrations for persons should be of a m u c h lower order of m a g n i t u d e . This article is cited because of its recent publication a n d the fact t h a t it contains refer ences o n a n u m b e r of previous arti cles on the toxicity of boranes from the University of Pittsburgh group. I n a previous article, it was stated, " A c u t e vapor toxicity studies carried out in the laboratory with deca borane (Bi 0 H 14 ) a n d p e n t a b o r a n e (B 5 H 9 ) in rats and mice indicate that they are extremely toxic and affect the central nervous system." T h e article, "Toxicity a n d Health H a z a r d s of Boron H y d r i d e s , " Ε. Η . K a r c k o w [Arch. Ind. Hyg. Occupa tional Med. 8, 335 (1953)], presents work performed by members of the Chemical Corps Medical Labora tories, A r m y Chemical Center, M a r y l a n d . I t is stated in this re port: " I n summary, the boron hydrides, diborane, p e n t a b o r a n e , and deca borane, are highly toxic compounds a n d present a serious health h a z a r d
Ideas Exchange it is a source of
for all the practical routes of entry into the body. A d e q u a t e ventila tion and hygienic and protective measures must be established for skin-contact, eye, a n d inhalation ex posures." Incidentally L. J. K u h n s a n d as sociates in a n article dealing with boron hydrides monitoring devices [Anal. Chem. 28, 1750 (1956)], start their article as follows, " T h e high toxicity of borane hydrides " T h e low values for the threshold limits established by the American Conference of Governmental In dustrial Hygienists, and which are given in my column, also are in dicative of a high toxicity.
Boron Detection Instruments DEAR D R . SCHRENK:
W e would appreciate information on manufacturer of field and auto motive boron detection instruments described in your Industrial H y giene column on metals of recent industrial importance ( I / E C , 49, 87 A, September 1957). R. M . TILLMAN
Development a n d Research D e p a r t m e n t Continental Oil Co. Ponca City,,Okla. Dr. Schrenk's
Answer:
This is in reply to your telegram regarding an automatic instrument for boron hydride detection. This instrument was described in an article entitled, "Boron Hydride Monitoring Devices—Employing a Triphenyltetrazolium Chloride R e agent," by L. J. K u h n s , R . H . Forsyth, and J. F. Masi, Callery Chemical Co., Callery, Pa. [Anal. Chem. 28, 1750 (1956)]. I do not know whether this in strument is being manufactured as yet. I t is suggested t h a t you write to the authors of the article at the address given for information on the availabilitv of the instrument. VOL. 49, NO. 12 ·
DECEMBER 1957
85 A
