UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

Date: February 6, 2014 

OFFICE OF 

CHEMICAL SAFETY AND 

POLLUTION PREVENTION 

SUBJECT: Inorganic Sulfites. Response to Comments on the Human Health Risk Assessment for 

Registration Review. 

PC Code: 077601 and 111409 

Decision No.: 486347 

DP Barcode: 0417022 

Registration No.: NA 

Petition No.: NA 

Risk Assessment Type: NA 

TXRNo.: NA 

MRIDNo.:NA 

Regulatory Action: Registration Review 

Case No.: NA 

CAS No.: 7681-57-4 and 7446-09-5 

40 CFR: § 180.444 

FROM: 

THRU: 

TO: 

Ideliz Negron-Encarnacion, Ph.D., Cf"h jl • J:?/u L 

Alexandra LaMay, M.Sci., Biologist v{ -{f( 

Risk Assessment Branch V 

Health Effects Division (7509P) 

Michael Metzger, Branch C 

Seyed Tadayon, Chemist 

Risk Assessment Branch 

Jeffrey Dawson, Chemist

Immediate Office 

Health Effects Division (7509P) 

Khue Nguyen, Risk Manager Reviewer 

Neil Anderson, Branch Chief 

Risk Management & Implementation Branch VII 

Pesticide Re-evaluation Division (7508P) 

Snowden Enterpises Inc., Quimetal Industrial S.A. and Quimas S.A., and Imal Ltda. have 

submitted comments on the Health Effect's Division (HED) document titled Inorganic Sulfites. 

Human Health Assessment Scoping Document in Support of Registration Review. (09/1 1/13; 

D411060). HED has presented the registrants' comments (Docket EPA-HQ-OPP-2013-0598) 

along with the corresponding HED response. 

Page 1 of4 
Snowden Enterprises Inc. 

Comment 1: The registrant corrects the tolerance reference in page 3 of the scoping document. 

Response: HED appreciates the correction and acknowledges that the reference is 40 CFR 

180.444. 

Comment2: 

• The registrant indicates that the scoping document specifies that sulfites are not a residue 

of concern (ROC). 

• The registrant expresses concern in aggregating non-pesticidal uses of sulfites with 

pesticidal uses of sulfites in the dietary assessment and requests the Agency to confine 

any reassessment of tolerances for sulfites only to pesticidal uses of sulfur dioxide and 

inorganic sulfites. 

Response: 

• The scoping document indicates that sulfate is not considered a ROC. Sulfite is 

identified as a residue of concern. 

• Section 408(b )(2)(ii) of FFDCA requires EPA to make a finding for each tolerance or 

tolerance exemption "that there is a reasonable certainty that no harm will result from 

aggregate exposure to the pesticide chemical residue, including all anticipated dietary 

exposures and all other exposures for which there is reliable information." The Agency 

will determine the best way to incorporate all residues of sulfites into its assessment 

consistent with this legal mandate. 

Comment 3: The registrant states that they are currently reviewing all the residue data and 

comparing it to the label. 

Response: The Agency requests that the registrant submit any residue data which supports 

current pesticidal use patterns and has not been previously considered by EPA. 

Comment 4: The registrant provided details regarding facilities that do not use wet scrubbing and 

directly vent treated air. Considering the restriction in the RED that facilities cannot release 

concentration more than 30 ppm ofS02 through venting, the registrant believes there is 

sufficient information that a bystander risk assessment is not needed. The registrant is willing to 

work with the Agency to provide information regarding use and release of S02 to clarify 

outstanding issues or concerns. 

Response: A bystander assessment will be completed, either quantitatively or qualitatively, 

depending on the specific information available describing the potential for these exposures. 

HED will work with the registrants as necessary to identify data needs. 

Comment 5: The registrant is not aware of human incidents involving the appropriate use of 

sulfur dioxide products. 

Page 2 of 4 
Response: HED appreciates the registrant input on human incidents and safety measures 

associated with the use of sulfur dioxide. 

Comment 6: The registrant would like to confirm that the request for monitoring data on 

fumigated commodities is required for sodium metabisulfite products only. 

HED Response: The Agency confirms that the request for monitoring data is required for sodium 

metabisulfite pads only. Please refer to Appendix F of the scoping document for more 

information regarding this data requirement. 

Quimetal Industrial S.A. and Quimas S.A. 

Comment 1: The registrant states that labeling indicating that the combined use of pads and 

liners is not allowed is a misunderstanding of the use pattern. 

Response: An initial fumigation with sulfur dioxide followed by the use of pads is 

recommended on the label of some sodium metabisulfite pads only. The labels of other end use 

products formulated with sodium metabisulfite do not contain this restriction. HED recommends 

a statement on the label of these products indicating that the combined use of pads and 

fumigation with sulfur dioxide is not allowed. This prohibition is only proposed for those labels 

of sodium metabisulfite products which currently do not have this restriction. Alternatively, the 

registrant can submit data to show that the combined use of sulfur dioxide and those sodium 

metabisulfite products would not result in over-tolerance residues. 

Comment 2: The registrant is concerned with the request for monitoring data and proposes the 

use of laboratory experimental data to establish the levels of so2 during transport, and upon 

opening packaging containers. 

Response: The Agency will consider all manner of research options for the data requirement. 

EPA will review and consider the laboratory data mimicking the conditions of use of the sodium 

metabisulfite pads and will determine if the data fulfill the data requirement. Adequate 

description of how the commercial conditions of use of the pads are reproduced in the laboratory 

and adequate justification of how the data are protective of actual occupational exposure should 

be submitted for consideration to determine if the study fulfills the data requirement. A protocol 

describing the proposed study should be submitted for Agency consideration before beginning 

the work. 

Imal Ltda. (Holzworth & Kato on behalf ot) 

Comment 1: The registrant states that sodium metabisulfite is not considered a fumigant in their 

industry. 

Page 3 of4 
Response: HED considers the sulfur dioxide generated by sodium metabisulfite responsible of 

the pesticidal activity. This gas is formed and released by the pads and considered a fumigant. 

Comment 2: The registrant requests that the anticipated data needs are specified with respect to 

the active ingredient to which they apply. 

Response: The registrant is referred to Appendix F of the seeping document which includes 

additional description of the active ingredient to which the each data requirement applies. The 

data requirements and respective active ingredients are: inhalation exposure study for 

applicators (compressed sulfur dioxide); product usage information (compressed sulfur dioxide); 

post-application inhalation exposure study (compressed sulfur dioxide); and monitoring data on 

fumigated commodities (sodium metabisulfite). 

Comment 3: The registrant is concerned with inclusion of label statement restricting the use of 

both sulfur dioxide pads and fumigation with sulfur dioxide gas but will wait to comment until 

more information is shared during registration review. 

Response: The registrant is referred to the response to Comment 1 of Quimetal Industrial S.A. 

and Quimas S.A. for additional information. 

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