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Re: Fw: Review of 149-44-0 D 

David Brooks to : Catherine Roman 08/18/2009 07:11 PM 

Cc: Greg Fritz, Mark Townsend, Victoria Vanroden,.jgarey,~wlrichards $ ~ 

Hi Catherine : 

I received a response back from our contractor and I am in agreement with their assessment. We believe 

that submitted studies adequately fulfill test rule requirements . If you feel it is necessary to modify our 

assessments, please let me know what section(s) you would like to have modified and suggested 

language to include . We have also included this information in HPVIS. 

Below is a copy of their email to me. 

Hi Dave, 

I just reviewed your e-mail and all of the documents that Joan [Gavey] sent me on CAS No. 149-44-0. 

As indicated by the e-mail from Catherine Roman on 8-12-09, the test rule specified that testing wcfs.'to 

be provided for 99% pure methanesulfinic acid, hydroxyl-, monosodium salt (CAS No. 149-44-0), but"' 

testing for human health endpoints was performed using this substance at unspecified purity (in the 

acute mammalian toxicity studies) or using this substance as a dihydrate form that also may contain 

stabilizers and impurities. 

The submitted documents included both a letter and a robust summary section that described the 

composition of the tested dihydrate form of the test rule chemical . Based on this information, and the 

physical/chemical properties of and relationship between the anhydrous and hydrated forms of 

methanesulfinic acid, hydroxyl-, monosodium salt described by Laura Morlacci below, I believe that the 

human health tests that have been conducted for the dihydrate form of this test rule chemical are 

adequate to characterize the toxicity of the test rule chemical, methanesulfinic acid, hydroxyl-, 

monosodium salt (CAS No. 149-44-0) . _- 

CID 

a 

Bill Richards 

Contractor to RAD 

703-413-9372 (office) 

301-717-4199 (cell) 

From Ullmann's Encyclopedia of Industrial Chemistry : 

6.1 . Properties 

rn 

c 

Sodium hydroxymethanesulfinate [149-44-0] is commercially available as the dihydrate HOCHZSOz 

Na ~ 2 H20, which crystallizes as white needles, mp 63 °C. Its solubility in water at room temperature is 

CONTAINS NO CBI 

,3ay~A®~ 
60 g/100 g. The salt is sparingly soluble in alcohol, and can be easily obtained pure from 60 % methanol . 

In moist air it decomposes slowly to products with noxious odors. The water of crystallization is lost upon 

heating to 120 °C, and then from 125 °C the compound undergoes a very exothermic decomposition to 

methanethiol, hydrogen sulfide, some formaldehyde, and sulfur dioxide, during which the temperature 

rises to 160 °C. The residue consists of sodium hydroxymethanesulfonate, sodium thiosulfate, and 

sodium sulfite . In solution the decomposition is pH and temperature dependent. Sodium 

hydroxymethanesulfinate reacts with sodium hydrogen sulfite to give sodium dithionite (Na 2SZ04) and 

sodium hydroxymethanesulfonate. The hydroxyl group is acidic and susceptible to salt formation. 

Laura 

Laura A. Morlacci, Ph.D. 

Senior Chemist 

2451 Crystal Drive, Suite 804 

Arlington, VA 22202 

(703) 413-9374 

(703) 413-9363 (FAX) 

Catherine Roman Hi David, Thanks for the information in your e-m. . . O8/18/2009 05:07 :25 PM 

From: Catherine Roman/DC/USEPA/US 

To : David Brooks/DC/USEPA/US@EPA 

Cc: Greg Fritz/DC/USEPA/US@EPA, Victoria Vanroden/DC/USEPA/US@EPA, Mark 

Townsend/DC/USEPA/US@EPA 

Date: 08/18/2009 05:07 PM 

Subject: Fw: Review of 149-44-0 

Hi David, 

Thanks for the information in your e-mail below. I found it very helpful in understanding this situation and 

whether the data will ultimately be acceptable. I will appreciate any additional information your contractor 

may provide . In talking to Greg Fritz of ICB about this, he thought it should be noted that any accepted 

data were "from tests of the dihydrate ." 

----- Forwarded by Catherine Roman/DC/USEPA/US on 08/18/2009 04:48 PM -- 

From: David Brooks/DC/USEPA/US 
To: 

Cc: 

Date: 

Subject: 

Hi Catherine, 

Catherine Roman/DC/USEPA/US@EPA 

Mark Townsend/DC/USEPA/US@EPA, Victoria Vanroden/DC/USEPA/US@EPA, 

jgarey@syrres.com 

08/18/2009 04:40 PM 

Re: Fw: Review of 149-44-0 

I am having our contractor take a second look at this issue. However, based on my initial discussions, I 

think our analysis is correct and purity of the substance as described appear to be adequate, and this 

material would probably be sold as > or = 98%a pure (that is, 98% pure dihydrate, not 98% pure anhydrous 

compound). The CAS number 149-44-0 corresponds to the anhydrous form - but keep in mind that 

TSCA does not recognize hydrates as being separate entities from the corresponding anhydrous material, 

even if the Chemical Abstracts Service assigns different CAS numbers to various hydrated forms of a 

chemical . In addition, the anhydrous form is probably not available due to the violent decomposition that 

follows dehydration . Even if one were to prepare the anhydrous form, it would have to be kept under 

strictly anhydrous conditions in order to prevent the hydrate from forming again. 

I asked our contractor to provide a short report on this issue by early next week. 

Dave