",",,'1EO S1"-4**~**

### :~"'"**~~. ~**  

# u UNITED STATES ENVIRONMENTAL PROTECTION AGENCY


### S 

# m WASHINGTON D.C., 20460



### :a (!l

### ~**~ ~** **~**

### ~..,,~ f\-{J

'AIL..

### PRO"(~(J

MEMORANDUM

SUBJECT:

FROM:

THRU:

TO: OFFICE OF CHEMICAL SAFETY
AND POLLUTION PREVENTION

February 15,2012

Product Chemistry, Environmental Fate, and Ecological Effects Scoping

Document in Support of Registration Review of Perboric acid, sodium salt, monohydrate (PBSM)

PC Code: 011105 DP Barcode: 394845

Decision No.: 455962 Registration Nos.: See Table 1

Petition No(s).: NA Regulatory Action: Ecological

Environmental Scoping Document

for Registration Review

Risk Assessment Type: Single Case No.: 5007

chemical

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

MRlD Nos.: See Page no

. 4 40 CFR: None

Srinivas Gowda, Microbiologist/Science Coordinator 

# Sroi**~ V~** **~** David Bays, PhD, Microbiologist

. Risk Assessment and Science Support Branch (RASSB) 

# Ii 

# J 1'1**~** Antimicrobials Division (751OP)

### ~ /'-" 

# /:?-

--

Nader Elkassabany, PhD, Branch Chief / /' 

### u'

Donna Randall, Ecological Risk Assessment Team Lea**~** Risk Assessment and Science Support Branch (RASSB)

Antimicrobials Division (751 OP)

Mark Hartman, Branch Chief

Lance Wormell, Team Leader

Seiichi Murasaki, Chemical Review Manager Regulatory Management Branch II

Antimicrobials Division (7510P)

Page 1 of7Page 2 of 7 Executive Summary

Sodium perborate monohydrate ( PB S M ) is an inorganic, perboric acid salt

, registered for use as a household laundry sanitizer. It was first registered in the United States on October 15,

1998 as an active ingredient in Tide with Bleach, Tide with B leach II, Gain with Bleach I, and

Gain with Bleach II. A Reregistration Eligibility Decision (RED) has not been issued by the Agency for PBSM because the initial registration date was after the November 1984, federal

mandated cutoff for initiation of the RED process. Currently there is one company with two registered products

, both are end

- use products formulated as soluble concentrates , and the active ingredient declarations are 4.74 and 5.28 percent. All product chemistry data requirements have

been sat isfied for this active ingredient.

For t he se sanitizing laundry use s of PB S M the Agency will not require any additional

environmental fate data or ecological effects data at this time. Due to its rapid reactivity and decomposition to oxygen, water

, and boric acid

— which are naturally occurring compounds widely found in soils, water, and food

— these uses of PB S M are not expected to cause direct or indirect adverse effects to nontarget organisms

. PB S M actually exists a s a dimer anion in which

two boron atoms are joined by two peroxo bridges , these peroxy functional group s make it very reactive, and it readily upon contact with aqueous medium hydrolyzes to hydrogen peroxide and borate. Hydrogen peroxide further rapidly breaks down into oxygen and water

. The q uantities of

boric acid and sodium and ions introduced to the environment from the use of PBSM are considered modest compared to amounts used for other, non

- pesticidal uses. Further, sodium, boric acid, and boron

- containing salts are ubiquitous in the environment. Sodium and b oron occur naturally in soils, water, fruits, vegetables

, and forage crops . Boron is an essential nutrient for plants as well as an essential element for many organisms and sodium is an essential element

for animals

. Thus they are not considered as stressors in this assessment. At this time the agency does not feel that any environmental fate and transport data will be required to assess PBSM’s

fate , effects or risk

. Bas ed on the rationale summarized above , the Agency expects that the registered uses of PBSM will have “no effect” on endangered or threatened terrestrial or aquatic species, or their designated critical habitats, as listed by the U.S. Fish and Wildlife Servi ce (USFWS) and the National Oceanic and Atmospheric Administration (NOAA).Page 3 of 7 Introduction

Perboric acid , sodium salt, monohydrate (PBSM) was first registered as an active ingredient with EPA on October 15, 1998. It’s m olecular formula NaBO 3 ·H 2 O is a

rep resentation of the average chemical composition but it’s elementary structural unit is a ctually

a dimer anion B 2 O 4 (OH) 4 2

- , in which two boron atoms are joined by two peroxo bridges. Presently, two end

- use products (EPs) are registered for use as a household laundry sanitizer and

these are listed in Table 1. A Reregistration Eligibility Decision (RED) has not been issued by

EPA for PBSM because the initial registration date was after November 1984, the federally

mandated cutoff for initiation of the RED process.

Table 1. Registered Products of PBSM

Registration

# Registration

Name Company

Name Formulation Type % of Active Ingredient

3573

- 56 Tide With Bleach II The Procter & Gamble Company Soluble

Concentrate

EP 5.28

3573

- 58 Gain With Bleach II The Procter & Gamble Company Soluble

Concentrate

EP 4.74

The Agency has conducted a review of the available product chemistry, environmental fate, and ecotoxicity data for PBSM . The findings are summarized below.

A. Product Chemistry Summary of the Perboric acid, sodium salt, monohydrate (95% TGAI Powder)

Common Name: Sodium Perborate Monohydrate

Chemical Name: Perboric acid, sodium salt, monohydrated (PBSM)

OPP Chemical Code: 011105 CAS Registry Number: 10332

- 33

- 9

Molecular Formula: NaBO 3 .H 2 O which exists as a di mer B 2 O 4 (OH) 4 2

- Molecular weight: 99.81 g/mole

Molecular Structure:

Color: White

. Physical State: Solid Granules

. Odor: Odorless

. Stability: The product is s table under ambient conditions. pH: 10 (concentration 15.2 g/l) UV/Visible absorption: Not applicable : i onic salt. Melting point: Melting point is 63°C at which point it decomposes.Page 4 of 7 Boiling Point: N ot applicable, p roduct is not a liquid. Density: 0.4

- 0.65 g/ml Dissociation Constant (pKa): Not applicable : i onic salt

. Log K o/w : Not applicable because product is an inorganic compound that decomposes in water.

Solubilities: Water : 15

- 16 g/l at 20 °C Vapor Pressure: This is not applicable because o f the ionic hydrated structure. It is considered to have negligible vapor pressure. Enforcement Analytical

Method: Titration for available oxygen.

All product chemistry data requirements have been satisfied for the active ingredient

PBSM (Source: MRIDs 43603601, 44425602 and 45198501 ).

B. Environmental Fate Summary

For the laundry sanitizing use of PBSM the Agency will not require any environmental

fate data at this time

. PBSM has only two indoor use registrations. This chemical is an inorganic

salt and environmental fate and transport test guidelines cannot be used to conduct the studies and obtain fate and transport parameters. In addition, it is a salt which contains a peroxy functional group which makes it very reactive, and it readily oxidizes/ b reaks down in aqueous medium and is not likely to persist. Moreover, it will produce known ions which are already present in the environmental media like water and soils. At this time the agency does not feel that any environmental fate and transport data will be required to assess PBSM’s fate risk and

characterization.

PBSM is considered to be a hydrogen peroxide releaser that also releases boric acid

, a degradate that does not contribute to the pesticidal activity of PBSM. In both terrestrial and aquati c systems, PBSM rapidly degrades to form hydrogen peroxide, water, oxygen, and a minor (<10 % of applied) amount of borate by both abiotic and biotic means. There are no environmental concerns for any of the degradation products of PBSM based on their ubiq uitous nature. In relation to boron, “Boric acid, borax, and boron

- containing salts are ubiquitous in the

natural environment. Boron occurs naturally in soil, water, fruits and vegetable s and forage crops, and is an essential nutrient for plants as well as an essential element for many organisms. Humans ingest naturally occurring boron in the diet, and there is some data to suggest that trace levels are required in the human diet. Available boron occurs in nature in the form of a number of closely related compounds which differ chiefly in the water of hydration associated with the

molecule an d are not easily differentiated”

. 1

1 U.S. Environmental Protection Agency. 199 3 . Reregistration Eligibility Decision for Boric Acid And Its Sodium Salts. Office of Prevention, Pesticides and Toxic Substances , Office of Pesticide Programs. September 1993

. EPA concluded that the relatively low levels of boron which would be added from pesticidal uses would not contribute to the already significant amounts of boron present in water and air

. As a result, EPA waived the requirement for

environmental fate data on boric acids and salts. Similarly, EPA waived the requirement for environmental fate data on hydrogen peroxide, based on the very rapid dissipation into water and

oxygen

. At this time there is no new information that changes this position for the PBSM

r egistration review.Page 5 of 7 Reaction of PBSM in Aqueous Solution

PB S M hydrolyzes in aqueous solution to release hydrogen peroxide and sodium metaborate. The following are the appropriate conversion factors for expressing concentrations of PB S M ( C PBSM ) as equival ent concentrations of :

• Boron : ; and

• Hydrogen peroxide:

In aqueous s olutions at room temperature equilibrium between PB S M and hydrogen peroxide

and sodium metaborate is instantly established (see reaction E quation I below).

Equation I

Further, the hydrogen peroxide i s removed from the equilibrium

— via degradation to active oxygen and water ( reaction Equation II)

— leading to an irreversible shift of the equilibrium given

in E quation I to the degradation products sodium metaborate and water. The release of active

oxygen also known as singlet oxygen ( 1 O 2 ) from hydrogen peroxide is the basis of the pesticidal activity of sodium perborate monohydrate.

– Equation II

The degradation product , sodium metaborate, dissocia tes in water and is present primarily as

dissociated boric acid or as boron (reaction Equation III and Equation IV)

. Boric acid and borates are naturally occurring compounds widely found in soils, water, and food. The bleaching activity of the perborates is associated with the hydrogen peroxide rather than the boric acid degradate.

Equation III

– Equation IV

Reaction s of PBSM and NOBS inside the Washing Machine

PB S M and sodium nonanoyloxvbenzenesulfonate ( NOBS ; PC Code: 089053;

CAS#91125

- 43

- 8 ) are active ingredients in the currently registered laundry detergent products

Tide With Bleach II (EPA Reg. No. 3573

- 56) and Gain With Bleach II (EPA Reg. No. 3573

- 58) by the Procter & Gamble Company. NOBS is a laundry bleach activator for hydroge n peroxide releasing chemicals s uch as PBSM. NOBS produces a highly active laundry ble ach from the less reactive hydrogen peroxide.Page 6 of 7 Detergent formulations containing NOBS are designed to help ensure rapid conversion of NOBS to the peroxy compound in the wash water. The peroxy compound itself is also short

lived due to rapid bleaching activity. To be effective in the wash cycle, the peracid precursor must be highly water

- soluble, undergo rapid and total perhydrolysis, and produce a peracid bleach with surface activity. Bleach activators like NOBS essentially transfer active oxygen from the peroxide to the stain via the peracid. Reactions inside the washing machine are summarized

below:

**•** PBSM supplies alkalinity (pH 10).

**•** PBSM hydrolyses, releasing hydrogen peroxide.

**•** Hydrogen peroxide perhydroly z es NOBS, producing pernonanoic acid. NOBS is referred to as a “bleach activator” since it produces a highly active laundry bleach pernonanoic acid from the less reactive hydrogen peroxide. These reactions are largely complete

within the first two minutes of the wash.

**•** Pernona no ic acid bleaches laundr y soils by additions of oxygen and sanitizes laundry

. Most of the peracid bleach is consumed in the first eight minutes of the wash.

Sodium Nonanoyloxybenzensulfonate (NOBS) Hydrogen peroxide Pernonanoic acid laundry bleach

Water Quality

PBSM and boron (or borates) are not identified as a cause of impairment for any water bodies listed as impaired under section 303(d) of the Clean Water Act, based on information provided at the Agency’s National Pesticides Cause of Impairmen t of Waters website (searched April 7, 2011) 2

. In addition, no Total Maximum Daily Loads (TMDL) have been developed for

PBSM

, based on information provided at the Agency’s National Pesticide TMDL web site (searched April 7, 2011) 3
http://www.epa.gov/owow/tmdl/ . More information on im paired water bodies and TMDLs can be

found at

. The Agency invites submission of water qu ality data for this pesticide. To the extent possible, data should conform to the quality standards in Appendix A of the OPP Standard Operating Procedure: Inclusion of Impaired Water Body and Other Water Quality Data in OPP’s Registration Review Risk Assessment and Management

Process ( see: http://www.epa.gov/oppfead1/cb/ppdc/2006/november06/session1

- sop.pdf ), in order to ensure they can be used quantitatively or qualitatively in pesticide risk assessment s.

2

. http://iaspub.epa.gov/tmdl_waters10/attains_nation_cy.cause_detail_303d?p_cause_group_id=885

3
http://iaspub.epa.gov/tmdl_waters10/attains_nation.tmdl_pollutant_detail?p_pollutant_group_id=885&p_pollutant_

gr oup_name=PESTICIDESPage 7 of 7 C. Ecological Effects Summary

For the laundry sanitizing use of PBSM the Agency will not require any additional environmental effects toxicity data at this time , either for the parent or its major decomposition or degradate products

. No exposure of nontarget organisms to PBSM is expected to occur in the environment because of its rapid reactivity and decomposition to oxygen, water , borates and

boric acid. Water and oxygen are nontoxic degradates. As previously discussed in the

Environmental Fate Su mmary section, s odium, boric acid, and boron

- containing salts are ubiquitous in the environment. Sodium and boron occur naturally in soils, water, fruits, vegetables, and forage crops. Boron is an essential nutrient for plants as well as an essential

elem ent for many organisms and sodium is an essential element for animals. There is sufficient ecological effects data for boric acid and its sodium salts

— discussed in the Boric Acid and Its Sodium Salt Reregistration Eligibility Decision 4

— documenting that bor on is practically nontoxic to birds, fish and aquatic invertebrates.

E ndangered Species Determination

Based on its rapid reactivity and decomposition to water, oxygen, and boric acid , the Agency expects that the registered indoor laundry sanitizing uses of PBSM will not lead to exposure and will have “no effect” on endangered or threatened terrestrial or aquatic species, or their designated critical habitats, as listed by the USFWS and the NOAA. However, the Agency will review any comments made by t he public on this document and will conduct an

environmental risk assessment if new in formation warrants such action. An ecological risk assessment planned during registration review allows the Agency to determine whether an antimicrobial pesticide’s use has “no effect” or “may affect” federally listed threatened or endangered species (listed species) or their designated critical habitats. When an assessment concludes that a pesticide’s use “may affect” a listed species or its designated critical habitat, the Agency will consult with the U.S. Fish and Wildlife Service and/or National Marine Fisheries Service (the Services), as appropriate.

Environmental Fate Data Gaps and Anticipated Work

For the laundry sanitizing use of PBSM the Agency will not require any additional

environmental fate information.

Ecotoxicity Data Gaps and Anticipated Work

Since no additional ecological effects studies are required, no ecotoxicity data gaps are
present.

4 U.S. Environmental Protection Agency. 1993. Reregistration Eligibility Decision for Boric Acid And Its Sodium Salts. Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs. September 1993.