UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON D.C., 20460 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

September 13, 2012 

MEMORANDUM 

SUBJECT: 

FROM: 

THRU: 

TO: 

Responses to Central Valley Regional Water Quality Control Board's 60-Day 

Public Comments on the Registration Review Preliminary Work Plan for PBSM. 

PC Code: 0111 05 DP Barcodes: 404927 

Decision Nos.: 469105 Registration Nos.: None 

Petition No(s).: NA Regulatory Action: Response to 60-

Day Public Comments 

Risk Assessment Type: Single Case No.: 5007 

chemical 

TXRNo.:NA CAS No.: 10332-33-9 

MRID Nos.: None 40 CFR: None 

Srinivas Gowda, M.S. Microbiologist <>~..J~~ Pat Jennings, Environmental Engineer ~o..t ~ 

David Bays, Ph.D., Microbiologist oOJl 

Risk Assessment and Science Support Branch (R.JXSSB) 

Antimicrobials Division (7510P) 

Donna 

Steven 

Randall, 

Weiss, Acting 

M.S. Ecological 

Branch Chief 

Risk Assessment 

% Ct/Team ~ Leader 

Risk Assessment and Science Support Branch (RASSB) 

Antimicrobials Division (751 OP) 

Seiichi Murasaki, Chemical Review Manager 

Regulatory Management Branch II 

Antimicrobials Division (751 OP) 

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Responses to Central Valley Regional Water Quality Control Board's 60-Day Public 

Comments on the Registration Review Preliminary Work Plan for PBSM. 

Staff of the Central Valley Regional Water Quality Control Board (Central Valley Water Board) 

has the following comments on the registration review preliminary work plan for perboric acid. 

1. Comment: We are writing to encourage EPA to conduct an environmental risk 

assessment for perboric acid, and provide information to justify this recommendation. 

Our main comment is that while there may not be any water bodies impaired due to 

perboric acid specifically, there are many water bodies impaired due to boron and 

sodium, which are the main components of perboric acid, sodium salt, monohydrate 

(PBSM). As noted in the work plan summary and the Environmental Fate and Effects 

Division scoping document for PBSM, perboric acid is very reactive and quickly breaks 

down into hydrogen peroxide, borate, boric acid and sodium. Thus, these are the 

appropriate constituents to examine for water quality risk assessment instead of the parent 

compound. 

Agency's Response: The Agency will perform an ecological risk assessment for 

degradates of PBSM that may enter surface water as a result of its use as a laundry 

sanitizer. 

2. Comment: In California there are 31 water bodies that are impaired due to high 

concentrations of boron. The 2008-2010 Clean Water Act Section 303(d) list for 

California contains 15 stream segments in the Central Valley, 11 segments in the Central 

Coast region, 4 segments in the Los Angeles region, and 1 segment in the Lahontan 

region that exceed water quality standards for boron. Only 4 of the total 31 water bodies 

impaired for boron statewide currently have a total maximum daily load (TMDL) in 

place. There are also 38 listings for sodium and an additional155 listings for other 

salinity-related impairments in California. Considering these listings, the statement that 

boron and sodium "are not considered as stressors" seems to be an inadequate 

environmental risk assessment of these constituents. Documentation for the specific 

303(d) listings is available at 

http://www. waterboards.ca. gov/water issues/programs/tmdl/integrated20 1 O.shtml 

Agency's Response: The Agency will revise the Antimicrobials Division's work plan 

summary dated March 2012 and the scoping document for PBSM, dated February 15, 

2012, to reflect information that the Central Valley Regional Water Quality Control 

Board has provided regarding water bodies in California that are impaired due to high 

concentrations of boron and sodium. The Agency will also revise this document to 

acknowledge that, in spite of boron's and sodium's natural occurrence and their function 

as essential nutrients, boron and sodium can reach levels in surface waters from both 

anthropogenic and natural sources that can lead to impairment of water bodies. In 

addition, the Agency will remove any statements that indicate that boron and sodium are 

not considered to be stressors. 

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3. Comment: In California and the arid West, naturally occurring constituents like boron 

and salts can cause water quality impairments during low flow conditions or due to 

altered landscapes. In these cases naturally occurring compounds are considered 

environmental stressors. Meeting salinity requirements, particularly for discharges to 

impaired waterbodies, is also often a challenge for publicly owned treatment works in the 

Central Valley Region. The Central Valley Water Board, and the dischargers we regulate, 

must direct considerable resources to our ongoing efforts to address the water quality 

impairments associated with boron and salinity. Prior to finalizing this registration review 

work plan and in future registration reviews for chemicals that contain or break down into 

these constituents, we encourage the US EPA to consider the environmental fate and 

ecological effects more deeply. In this case, US EPA should specifically explore the 

potential significance of discharges to municipal wastewater treatment plants that 

discharge to boron and/or salinity impaired waters. 

Agency's Response: The Agency recognizes that use of PBSM as a laundry sanitizer 

may potentially lead to the presence of degradates of PBSM in surface water bodies 

downstream of domestic wastewater treatment plants that do not remove these degradates 

during wastewater treatment. Therefore, we concur with the need to further explore the 

potential significance of releases of PBSM used as a laundry sanitizer to surface waters 

downstream of domestic wastewater treatment plants, including those surface water 

bodies with limited dilution and flow potential. The Agency will revise this work plan 

summary and scoping document to indicate that an ecological risk assessment of downthe-drain releases of PBSM from use as a laundry sanitizer will be performed and will 

include a list with justifications of environmental fate and ecological effects data 

requirements for degradates of PBSM that will be needed to perform this assessment. 

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