Re: Soluble uranium chemical intake limits - NRC vs OSHA/NIOSH

[thomas.labone@SRS.GOV]

Take a look at Chapter 5 of "Uranium, Plutonium, Transplutonic Elements," 

which was edited by Hodge, Stannard, and Hursh and published by 

Springer-Verlag in 1973 (I think it is out of print), and Chapter 16 of 

Radioactivity and Health (DOE/RL/01830-T59), by Stannard, which was 

published by DOE/PNL in 1988.  I believe that it is still in print.



**********************************

*  Thomas La Bone              *

*  thomas.labone@srs.gov   *

*  803-952-9535                   *

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Huey0001@AOL.COM 

Sent by: owner-radsafe@list.Vanderbilt.Edu

03/20/2004 01:05 PM

Please respond to

Huey0001@AOL.COM





To

radsafe@list.Vanderbilt.Edu

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pjhitcho@sevenson.com

Subject

Soluble uranium chemical intake limits - NRC vs OSHA/NIOSH













A question came up by the Industrial Hygiene staff here.  The question is; 

Why does 10 CFR 20.1201(e) allow workers to receive 10 milligrams of 

soluble uranium a week when OSHA only allows 2.5 milligrams per week 

soluble U?



10 CFR 20.1201(e) states “In addition to the annual dose limits, the 

licensee shall limit the soluble uranium intake by an individual to 10 

milligrams in a week in consideration of chemical toxicity (see footnote 3 

of appendix B to part 20).” 



Footnote 3 states “For soluble mixtures of U-238, U-234, and U-235 in air, 

chemical toxicity may be the limiting factor (see § 20.1201(e)). If the 

percent by weight (enrichment) of U-235 is not greater than 5, the 

concentration value for a 40-hour workweek is 0.2 milligrams per cubic 

meter of air average.  For any enrichment, the product of the average 

concentration and time of exposure during a 40-hour work week shall not 

exceed 8E-3 (SA) uCi-hr/ml, where SA is the specific activity of the 

uranium inhaled.  The specific activity for natural uranium is 6.77E-7 

curies per gram U.”



It appears that Foot Note 3 in 10 CFR 20 Appendix B is using the insoluble 

U limit published by OSHA and NIOSH.



OSHA and NIOSH exposure limits for soluble U is 0.05 milligrams per cubic 

meter and 0.2 milligrams per cubic meter for insoluble U.



Any feed back would be appreciated.



Thanks





Paul Jung, RRPT

Radiation Safety Officer

Sevenson Environmental Services, Inc.

2749 Lockport Rd

Niagara Falls, NY  14305

716-284-0431

716-284-1796 fax

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