MEMORANDUM

To:	Margaret Sheppard, U.S. EPA

CC:	Bella Maranion, Monica Shimamura, and Melissa Fifer, U.S. EPA

From:	Jenny Tanphanich, Kara Altshuler, and Mark Wagner, ICF
International 

Date:	March 8, 2010 

Re:	Evaluation of Lithium Bromide Toxicity

(EPA Contract Number EP-W-06-008 Task Order 038, Task 06)



This memorandum presents ICF’s evaluation, from a toxicological and
exposure standpoint, of the following statement for use in the
development of an exposure limit for the Significant New Alternatives
Program. 

"Water/lithium bromide absorption exhibits low toxicity.  Lithium
bromide has a 

24-hour CEGL [Continuous Exposure Guidance Level] value of 1 mg/m3."

Please contact Mark Wagner at 202-862-1155 with any questions or
comments.

ICF has conducted a brief review of recent lithium bromide (LiBr)
production and use data, as well as information regarding toxicity of
lithium containing compounds and potential exposure data for LiBr in its
potential use in absorption-style chillers.  Based on this review, we
believe the following statement is valid: “Water/lithium bromide
absorption exhibits low toxicity.  Lithium bromide has a 24-hour CEGL
[Continuous Exposure Guidance Level] value of 1 mg/m3.”  The CEGL is
appropriate as a foundation for development of an exposure limit for
SNAP use.  It is based on an estimated concentration of LiBr that would
be necessary to achieve a therapeutic dose of lithium in the bloodstream
(using a known therapeutic dose of lithium carbonate), with appropriate
conversions to account for inhalation exposure and clear and appropriate
application of uncertainty factors.  The CEGL value is based on a
24-hour, 90-day exposure duration.  When used for occupational workers,
it could be adjusted to reflect an 8-hour exposure, which would give an
exposure limit of 3 mg/m3 for 90 days.

Dermal uptake of water/lithium bromide slurry (the expected form of LiBr
formulations used as a secondary refrigerant) is expected to be minimal.
 A default dermal permeability factor (Kp) of 1E-03 is assumed based on
EPA’s RAGS, Part E and Dermal Exposure Assessment guidance documents.
Oral uptake of LiBr powder or LiBr/water slurry is also expected to be
insignificant in an occupational environment.  The 3 mg/m3 exposure
limit can be used to control potential inhalation exposures. 
Appropriate personal protective equipment (e.g. masks, etc.) should be
used by any occupational worker responsible for handling LiBr powder. 

 See   HYPERLINK
"http://www.osha.gov/pls/oshaweb/owastand.display_standard_group?p_toc_l
evel=1&p_part_number=1910#1910_Subpart_I" 
http://www.osha.gov/pls/oshaweb/owastand.display_standard_group?p_toc_le
vel=1&p_part_number=1910#1910_Subpart_I  for full list of OSHA personal
protective equipment standards. 

