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EPA REGISTRATION DIVISION COMPANY NOTICE OF FILING FOR PESTICIDE PETITIONS

PUBLISHED IN THE FEDERAL REGISTER   

EPA Registration Division contact: William Cutchin, (703) 305‐7990

INSTRUCTIONS:  Please utilize this outline in preparing the pesticide petition. In cases

where the outline element does not apply, please insert “NA‐Remove” and maintain

the outline. Please do not change the margins, font, or format in your pesticide

petition. Simply replace the instructions that appear in green, i.e., “[insert company

name],” with the information specific to your action.

TEMPLATE:

Rhodia, Inc.

2E8017

EPA has received a pesticide petition 2E8017 from Rhodia Inc., c/o SciReg, Inc.,

12733 Director’s Loop, Woodbridge, VA 22192 proposing, pursuant to section 408(d) of

the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a(d), to amend 40 CFR

part 180 to establish an exemption from the requirement of a tolerance for cationic

hydroxypropyl guar (CAS No. 71329‐50‐5), with a minimum number average molecular

weight (in amu) of 500,000, under 40 CFR 180.920 when used as an inert ingredient in

pesticide formulations. EPA has determined that the petition contains data or

information regarding the elements set forth in section 408 (d)(2) of  FDDCA; however,

EPA has not fully evaluated the sufficiency of the submitted data at this time or whether
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the data supports granting of the petition. Additional data may be needed before EPA

rules on the petition.

[This tolerance exemption petition summarizes and relies upon available data for

cationic hydroxypropyl guar and the structurally similar substance, guar gum. The

cationic hydroxypropyl guar data presented in this tolerance exemption petition are

on two products. One product had a molar substitution (MS) of 0.6 and a degree of

substitution (DS) of 0.1 and the other product had a MS of 0.6 and a DS of 0.3. In

addition, test results on cationic guars are included as supporting data.]

A. Residue Chemistry

1. Plant metabolism. Rhodia is requesting that cationic hydroxypropyl guar be

exempt from the requirement of a tolerance under 40 CFR 180.920. Therefore, plant

metabolism in treated crops is not relevant.

2. Analytical method. Rhodia is requesting that cationic hydroxypropyl guar be

exempt from the requirement of a tolerance under 40 CFR 180.920. Therefore, Rhodia

believes that an analytical method to determine residues in treated crops is not

relevant.

3. Magnitude of residues. Rhodia is requesting that cationic hydroxypropyl guar

be exempt from the requirement of a tolerance under 40 CFR 180.920. Therefore,

Rhodia believes that data on the magnitude of residues in treated crops is not

relevant.

B. Toxicological Profile

1. Acute toxicity.  
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Acute Oral Toxicity

The acute oral toxicity of cationic hydroxypropyl guar (MS: 0.6/DS: 0.1) was

evaluated in Sprague Dawley rats according to OECD Guideline 401. The test

article was administered once in distilled water at a dose level of 2,000 mg/kg

to five males and five females. Examinations for mortality, body weight gain,

and abnormal clinical signs were performed for the 14‐day study period. All

surviving animals were euthanized and necropsied at the end of the observation

period. No abnormal clinical signs were noted in male animals. Piloerection and

hypoactivity were observed in all females immediately after dosing and until

Day 2 in one female. One female died on Day 3 and another one on Day 8. The

necropsy of the animals dying during the study, showed perinasal staining in

one animal, but due to autolysis of the carcass, no detailed observations were

possible. The second animal was noted to have both the stomach and

duodenum filled with free blood and blood clots, and the remaining tissues

were pale due to gastric hemorrhage. No body weight loss was recorded

throughout the study period. There were no macroscopic findings in animals

sacrificed at the end of the study. Cationic hydroxypropyl guar had some toxic

effect when orally administered to rats at a single dose level of 2,000 mg/kg

since 20% mortality was observed. The LD50 is greater than 2,000 mg/kg.  

Another acute oral toxicity study was conducted with cationic hydroxypropyl guar

(MS: 0.6/DS: 0.3) in Sprague Dawley rats according to OECD Guideline 401. The test

article was administered at 2,000 mg/kg to a group of five males and five females

using a dose volume of 20 mL/kg in purified water. Examinations for mortality, clinical

signs, and body weight gain were performed during the 14‐day study period. All

surviving animals were euthanized and necropsied at the end of the observation

period. No deaths occurred. General behavior of the test subjects was not affected by

treatment. A slight reduction in body weight gain was observed during the first week

following treatment. At necropsy, a macroscopic examination revealed no

abnormalities. T he acute oral LD50 for cationic hydroxypropyl guar was determined to

be greater than 2,000 mg/kg.

Cationic guar (approx. DS: 0.17 to 0.2) was tested for acute oral toxicity in Sprague‐

Dawley rats. The test article was administered once by gavage as a 40% (w/v) dilution
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in corn oil at dose levels of 7.1, 10.0, 14.2, and 20.0 g/kg to groups of five males and

five females. Examinations for mortality and clinical signs were performed for the 15‐

day study period. No deaths occurred at 7.1 g/kg. Clinical signs observed were a

decrease in motor activity within three days after treatment. Two animals lost weight.

In the group treated with 10.0 g/kg, one male died on Day 2. In the 14.2 g/kg group,

nine out of ten animals died between Days 1 and 3. Finally, all of the animals treated

with 20.0 g/kg died between Days 1 and 5. Clinical signs and necropsy observations

included decrease in motor activity, piloerection, ataxia, tremor, red nasal discharge,

clear oral discharge, urinary staining of the abdomen, soft stool, fecal staining of the

abdomen, hypothermia, as well as black patches on the liver, kidney, and heart at the

highest doses. Clinical signs usually disappeared within four days after treatment. The

oral acute LD50 for cationic guar was calculated to be 12.5 g/kg.

Another cationic guar (approx. DS: 0.1 to 0.13) was tested for acute oral toxicity

in male Sprague Dawley rats. The test article was administered at doses level of

2,000, 5,000, 10,000, and 20,000 mg/kg in food to 10 fasted animals. Each rat

was observed daily for mortality and other signs of gross toxicity for 14 days.

There were no mortalities reported during the test period. It was determined

that the LD50 for cationic guar is greater than 20,000 mg/kg.

Acute Dermal Irritation

Cationic hydroxypropyl guar (MS: 0.6/DS: 0.1) was tested for skin irritation in

New Zealand albino rabbits according to OECD Guideline 404. 0.5 g of the test

article was moistened with water and applied to the intact skin of six animals

for four hours, under semi‐occlusive dressing. Cutaneous examinations were

performed at 1, 24, 48, and 72 hours and 7 days after removal of the patches.

Very slight erythema was noted in one rabbit at one hour. This reaction

disappeared at 24 hours. No other cutaneous reactions were observed

throughout the observation period. Therefore, cationic hydroxypropyl guar is

not considered a skin irritant.
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A second acute dermal irritation study was conducted with cationic hydroxypropyl

guar (MS: 0.6/DS: 0.3) in three male New Zealand White rabbits according to OECD

Guideline 404. The test article was applied on a moistened compress in a single

dermal dose of 0.5 mL, to a 6 cm2 clipped area of the skin for four hours under a semi‐

occlusive dressing. The cutaneous examinations were performed at 1, 24, 48, and 72

hours after removal of the dressing. No cutaneous reactions were observed

throughout the observation period. Therefore, cationic hydroxypropyl guar is not

considered a skin irritant.  

Acute Eye Irritation

Cationic hydroxypropyl guar (MS: 0.6/DS: 0.1) was tested for acute ocular

irritation in New Zealand albino rabbits according to OECD Guideline No. 405.

The test article was administered at a dose level of 0.1 ml (approximately 68

mg) into the inferior conjunctival sac of the right eye of six animals. The eyes

were not rinsed. The ocular examinations were performed at 1, 24, 48, and 72

hours and 7 days after administration. Conjunctival reactions were noted one

hour after instillation of the test material. After 24 hours, slight to well defined

chemosis and/or redness of the conjunctiva persisted in six animals. This irritant

effect decreased rapidly and after 48 and 72 hours slight conjunctival reaction

remained in one animal only. No irritation was observed after 7 days. No

corneal or iris lesions were observed. The mean scores (24‐48‐72 hours)

calculated for the six animals were 0.39 for conjunctival chemosis and 0.44 for

conjunctival redness. Based on the reported scores, the Maximum Mean Total

Score (MMTS) can be calculated as 4.7 at 24 hours (over a scale of 110 according

to the modified Kay and Calandra interpretation of eye irritation). Therefore,

cationic hydroxypropyl guar had some mild irritating effects in the eye, but they

were readily reversible.

A second acute eye irritation study was conducted with cationic hydroxypropyl guar

(MS: 0.6/DS: 0.3) in three male New‐Zealand White rabbits according to OECD

Guideline 405. The test article was instilled in a single dose of 0.1 mL, into the

conjunctival sac of the left eye of each animal. The right eye remained untreated and

served as a control. The eyes were not rinsed. Ocular examinations were performed 1,

24, 48, and 72 hours after the instillation. Very slight (one animal) or slight (two
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animals) conjunctival chemosis was observed at one hour, as well as very slight

redness in one animal. White purulent discharge was also observed in two animals at

one hour. These reactions were no longer present 24 hours after the instillation. The

mean scores (24‐48‐72 hours) calculated for each animal were 0.0 for conjunctival

chemosis and redness, iris lesion and corneal opacity. Therefore, cationic

hydroxypropyl guar was determined to be non‐irritating to the eye.  

Cationic guar (approx. DS: 0.17 to 0.2) was tested for acute ocular irritation in six New

Zealand albino rabbits. The test article was administered at a dose level of 0.1 mL of

powder into the inferior conjunctival sac of one eye of each animal. The other eye

remained untreated and served as a control. The ocular examinations were performed

at 24, 48, and 72 hours and then at Days 4, 7, 10 and 14 after administration. Corneal

opacity (grade 1) was observed in two animals and cleared by Day 2 or 3. Slight dulling

of the normal luster was observed within 48 hours in five out of six animals, and was

present in one animal at Day 3 and 4. Ulceration of the cornea was also present in all

of the animals during 48 hours after treatment. Iris lesions were present in all of the

six animals at Day 1 (grade 1), but cleared thereafter. The mean score calculated over

the six animals for the 24‐48‐72 hours time‐period was 0.3. Conjunctival redness

(grade 2 or 3) was observed in all of the animals at 24 hours. This reaction had cleared

by Day 3 or 4, but was observed again in two animals at Day 10. Chemosis (grade 1 to

3) was present at 24 hours, but reversed by Day 4. The mean scores (24‐48‐72 hours)

calculated over the six animals were 1.6 for conjunctival redness and 1.2 for chemosis.

In addition, slight to moderate discharge was observed at 24 hours. All of these

reactions had cleared by the end of the observation period. Therefore, cationic guar is

considered as slightly irritating to the eyes.

Cationic guar (approx. DS: 0.1 to 0.13) was tested for acute ocular irritation in

six New Zealand albino rabbits according to the Draize method. The test article

was administered at the dose level of 100 mg undiluted into the right eye, and

the left eye served as a negative control. The eyes were not rinsed. Ocular

examinations were performed 1, 24, 48, 72 hours, and 7 and 14 days after

administration. At one hour following administration, test material coated the

eyes precluding a valid evaluation of the corneas and irises. Corneal opacity

(grade 1) was observed in five of six animals from 24 hours and cleared by 72

hours to Day 7. Iritis (grade 1) was observed in four of six animals and cleared

by Day 7 in all of the animals. The mean scores calculated for all the animals
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over 24‐72 hours were 0.66 for corneal opacity and 0.66 for iritis. Conjunctival

redness and chemosis (grade 1 or 2) were observed in all the animals from one

hour following administration and cleared by Day 14. The mean scores

calculated for all the animals over the 24‐72 hour period were 1.77 for redness

and 0.83 for chemosis. In addition, discharge (grade 1 to 3) was noted in most of

the animals from the one hour observation time. Therefore, cationic guar is

considered as slightly irritating to the eyes.  

Skin Sensitization

The sensitization potential of cationic hydroxypropyl guar (MS: 0.6/DS: 0.1) was

evaluated on Dunkin‐Hartley guinea pigs according to the maximization method

of Magnusson and Kligman, described in OECD Guideline 406. Ten test and five

control female guinea pigs were included in this study. An induction treatment

was carried out as follows: intradermal injections of the test article at 1% (w/w)

in paraffin oil and Freund's complete adjuvant were performed on Day 1 in the

scapular area of the back. The same skin site received a cutaneous occlusive

treatment (test article applied at 20% w/w in paraffin oil) on Day 8 for 48 hours.

The animals were challenged on Day 22 with a cutaneous occlusive application

of the test article at 20% w/w in paraffin oil for 24 hours in one flank. The

cutaneous reactions were evaluated 24 and 48 hours after patch removal.

Control animals received intradermal injections of paraffin oil and Freund's

complete adjuvant as well as cutaneous applications of paraffin oil during the

induction period and were submitted to the challenge treatment. No deaths and

no clinical signs were noted throughout the study. After the challenge, no

cutaneous response attributable to a sensitizing reaction was noted in guinea

pigs treated with cationic hydroxypropyl guar. Therefore, cationic

hydroxypropyl guar is not classified as skin sensitizer.

A second study to determine the skin contact sensitization potential of cationic

hydroxypropyl guar (MS: 0.6/DS: 0.3) was evaluated on Dunkin Hartley guinea pigs

according to the maximization method of Magnusson and Kligman, described in OECD

Guideline 406. Concentrations to be used in the main study were determined in a

preliminary test on one male and one female. Twenty test (10 male and 10 females)

and ten control (5 males and 5 females) animals were included in this study. An
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induction treatment was carried out as follows: intradermal injections of the test

article at 5% (w/v) in saline and Freund's complete adjuvant were performed on Day 1

in the scapular area of the back. On Day 7, the same skin sites were pre‐treated by

sodium lauryl sulfate followed on Day 8 by a cutaneous occlusive application of the

undiluted test article for 48 hours. The animals were challenged on Day 22 with a

cutaneous occlusive application of the test article applied undiluted for 24 hours on

one flank. Control animals received intradermal injections of saline and Freund's

Complete Adjuvant as well as cutaneous applications of saline during the induction

period and were submitted to the challenge treatment. The cutaneous reactions were

evaluated 24 and 48 hours after patch removal. No deaths related to treatment and

no clinical signs were noted throughout the study. At challenge, no dermal reactions

were observed in any of the animals. Therefore, cationic hydroxypropyl guar is not

considered a skin sensitizer.  

The sensitization potential of cationic guar (approx. DS: 0.17 to 0.2) was assessed in

Hartley guinea pigs according to a modification of the method described by Buehler.

Fifteen guinea pigs (male and female) were included in each group. For induction, the

test substance was prepared as a 5% (w/v) solution in distilled water and applied at a

dose of 0.2 mL on a clipped area of the back, under an occlusive dressing for six hours.

Animals in the positive control group were treated under the same conditions with

DNCB at 1% (w/v) suspension in acetone water, and negative controls received water.

The sensitizing procedure was repeated three times a week for three weeks. Animals

were examined daily for mortality and signs of systemic toxicity. Two weeks after the

last sensitizing treatment, the animals were challenged with a cutaneous application

on two clipped areas of the back, under an occlusive dressing for six hours. As a

control, an additional group of five unsensitized animals were treated with the test

material. Examinations for cutaneous reactions were performed at 6, 24, and 48

hours after challenge. A second challenge was conducted 48 hours following the first,

according to the same procedure. Only one animal showed slight transient erythema

reaction (grade 1) at six hours in the test group (1st challenge), and in one animal of

the control group at the second challenge. No other cutaneous reactions were

observed in both vehicle control animals and those treated with cationic guar.

Reactions observed in the positive control group confirmed the susceptibility of the

animals to dermal sensitization. One death occurred on Day 13 in the control group

receiving distilled water, but was considered unrelated to treatment. No signs of

systemic toxicity were observed during the study; however, sporadic incidences of
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urinary and fecal staining of the abdomen and soft stool were observed. Cationic guar

is not considered to be a skin sensitizer under the above experimental conditions.]

2. Genotoxicty. The mutagenic potential of cationic hydroxypropyl guar (MS:

0.6/DS: 0.1) was assessed in the Salmonella typhimurium/microsomal assay,

according to OECD Guideline 471. Strains TA 1535, TA 1537, TA 98, TA 100, and TA

102 were used in presence and absence of metabolic activation system from liver

fraction of Aroclor 1254‐induced rats (S9‐mix). The test article was dissolved in water

and dose levels used in the main assays were: 312.5, 625, 1,250, 2,500, and 5,000

μg/plate with or without S9‐mix. Two independent tests were performed according

to the direct plate incorporation method, except for the second test with S9‐mix

which was performed according to the preincubation method. No cytotoxicity was

observed up to the maximum dose tested (5,000 μg/plate). Cationic hydroxypropyl

guar did not demonstrate any in vitro mutagenic activity in this bacterial test system.  

Cationic hydroxypropyl guar (MS: 0.6/DS: 0.3) was assessed in another Salmonella

typhimurium/microsomal assay and in Escherichia coli according to OECD Guideline

471. The test article was diluted in distilled water. In a preliminary study, cytotoxicity

was observed at all concentrations ranging from 20 to 12,500 μg/plate and in all

strains. No cytotoxicity was observed in a preliminary study performed with TA 98, TA

100, and both strains of E. coli, and with concentrations ranging from 4 to 2,000

μg/plate, with and without metabolic activation. Four strains of Salmonella

typhimurium (TA 1535, TA 1537, TA 98, and TA 100) and two strains of Escherichia coli

(WP2uvrA and WP2pKM101) were used in the main assay, in the presence or absence

of metabolic activation system from the liver fraction of Aroclor 1254‐induced rats

(S9‐mix). The test article was diluted in distilled water with 30% citric acid (5μL of citric

acid for 10 mL distilled water). Two independent experiments were performed, with

appropriate positive and negative controls. Selected dose levels were 62.5, 125, 250,

500, and 1,000 μg/plate, with and without S9‐mix. All determinations were made in

triplicate. No toxicity was observed in both experiments towards all the strains tested.

There was no significant increase in the number of revertants in any of the six

bacterial strains tested, and at any dose level, with or without S9‐mix. Cationic

hydroxypropyl guar did not demonstrate any in vitro mutagenic activity in this

bacterial test system.]
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3. Reproductive and developmental toxicity. No reproductive and

developmental toxicity data are available for cationic hydroxypropyl guar. There are,

however, data on the substantially similar compound guar gum.

Teratogenicity studies with guar gum in mice, rats, and hamsters did not indicate that

guar gum is a teratogen in mice at 170 mg/kg and 800 mg/kg. Similar negative findings

were seen in rats up to 900 mg/kg and up to 600 mg/kg in hamsters.  

Rats were fed guar gum at 0, 1, 2, 4, 7.5, and 15% in the diet for 13 weeks before

mating, during mating, and throughout gestation. No effects on parental fertility, fetal

development, sex distribution, and no malformations of the pups were observed.]

4. Subchronic toxicity. No subchronic toxicity data are available for cationic

hydroxypropyl guar. There are, however, data on the substantially similar compound

guar gum.

Male and female Osborne‐Mendel rats, approximately 4 weeks old, were fed guar

gum for 13 weeks at levels of 0, 1.0, 2.0, 4.0, 7.5, or 15.0% in the diet. Body weights,

organ weights, hematology, clinical chemistry, and histology were evaluated. Body

weights were significantly reduced in females of all the treated groups and in males at

the 7.5% and 15.0% dietary levels. Utilization of the guar gum was poor and, at the

15.0% level, there was some reduction in bone marrow cellularity. Serum glucose

values and kidney weights were the only other parameters showing dose‐related

trends.

No differences were observed in weight gain and food efficiency in male rats fed with

6% guar gum for 91 days.

In another study with male and female rats fed in their diet 0, 1, 2, or 5% guar gum for

90 days, no effects were observed on the behavior and survival. Growth was relatively

low in males fed 2% and 5% and food efficiency was slightly diminished in males of the
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5% group. Blood urea nitrogen values were slightly increased in males at the 5% level.

The relative weight of the cecum was increased at the 2% and 5% levels in both sexes,

that of the thyroid only in males. There were no gross and histopathological changes.

No adverse effects were reported in dogs that were fed 0, 1, 5, or 10% of a precooked

mixture of guar and carob bean for 30 weeks or in monkeys that were fed 1 gram of

guar flour for 24 months.]

5. Chronic toxicity. No carcinogenicity data are available for cationic

hydroxypropyl guar. There are, however, data on the substantially similar compound

guar gum.

No evidence of carcinogenicity was found in male and female F344 rats and B6C3F1

mice administered diets containing 25,000 or 50,000 ppm guar gum for 103 weeks. A

reduction in the mean body weight of the high dose females and of the feed

consumption was observed, as compared with the controls. No compound‐related

clinical signs or adverse effects on survival were observed. There was no increase in

the incidence of tumors that could be related to the test substance.]

6. Animal metabolism. [NA‐Remove.]

7. Metabolite toxicology. [NA‐Remove.]

8. Endocrine disruption. [NA‐Remove.]

C. Aggregate Exposure

1. Dietary exposure. In examining aggregate exposure, section 408 of the

Federal Food, Drug, And Cosmetic Act (FFDCA) directs EPA to consider available
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information concerning exposures from the pesticide residue in food and all other

nonoccupational exposures, including drinking water from ground water or surface

water and exposure through pesticide use in gardens, lawns, or buildings (residential

and other indoor uses).

Dietary and Non‐Dietary Exposure

Results of toxicological studies conducted with cationic hydroxypropyl guar

demonstrate the substance is of low toxicity. In addition, cationic hydroxypropyl guar

is a slightly modified form of guar gum, a natural polymer which is an affirmed GRAS

substance of low toxicity. Cationic hydroxypropyl guar is also structurally similar to

hydroxypropyl guar, carboxymethyl guar, and carboxymethyl‐hydroxypropyl guar,

other slightly modified forms of guar gum and all of which are exempt from the

requirement of a tolerance. EPA reassessed the tolerance exemption for

hydroxypropyl guar in 2005 and concluded that there is a reasonable certainty of no

harm to any population subgroup that will result from aggregate exposure to

hydroxypropyl guar when considering dietary exposure and all other nonoccupational

sources of pesticide exposure for which there is reliable information. Based on results

from toxicological studies, its close structural relationship to guar gum, hydroxypropyl

guar, carboxymethyl guar, and carboxymethyl‐hydroxypropyl guar, as well as, its high

molecular weight and low likelihood of absorption via any route of exposure, cationic

hydroxypropyl guar can also be considered to be a low toxicity substance with a

reasonable certainty of no harm from dietary exposure and all other nonoccupational

sources of exposure.

i. Food. [NA‐Remove.]

ii. Drinking water. [NA‐Remove.]

2. Non‐dietary exposure. The physical and chemical characteristics of cationic

hydroxypropyl guar lead to the conclusion that there is a reasonable certainty of no
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harm from exposure to the polymer from exposure to the polymer through non‐

dietary means.

D. Cumulative Effects

Section 408(b)(2)(D)(v) of the FFDCA requires that, when considering whether to

establish, modify, or revoke a tolerance, the Agency consider “available information”

concerning the cumulative effects of the particular pesticide’s residues and “other

substances that have a common mechanism of toxicity.”

Results of toxicological studies conducted with cationic hydroxypropyl guar

demonstrate the substance is of low toxicity. In addition, cationic hydroxypropyl guar

is a slightly modified form of guar gum, a natural polymer which is an affirmed GRAS

substance of low toxicity. Cationic hydroxypropyl guar is also structurally similar to

hydroxypropyl guar, carboxymethyl guar, and carboxymethyl‐hydroxypropyl guar,

other slightly modified forms of guar gum and all of which are exempt from the

requirement of a tolerance. According to EPA’s 2005 tolerance exemption

reassessment document for hydroxypropyl guar, it was concluded that hydroxypropyl

guar is a low toxicity chemical; therefore, the resultant risks separately and/or

combined should also be low. Like guar gum, hydroxypropyl guar, carboxymethyl

guar, and carboxymethyl‐hydroxypropyl guar, cationic hydroxypropyl guar is a high

molecular weight, low toxicity molecule with a low likelihood of absorption through

any route of exposure. Resultant risks, separately and/or combined with other

substances that may have a common mechanism of toxicity, should be low for cationic

hydroxypropyl guar. Rhodia does not expect any adverse cumulative effects

associated with the use of cationic hydroxypropyl guar.]

E. Safety Determination

1. U.S. population including infants and children .
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Results of toxicological studies conducted with cationic hydroxypropyl guar

demonstrate the substance is of low toxicity. In addition, cationic hydroxypropyl guar

is a slightly modified form of guar gum, a natural polymer which is an affirmed GRAS

substance of low toxicity. Cationic hydroxypropyl guar is also structurally similar to

hydroxypropyl guar, carboxymethyl guar, and carboxymethyl‐hydroxypropyl guar,

other slightly modified forms of guar gum and all of which are exempt from the

requirement of a tolerance. According to EPA’s 2005 tolerance exemption

reassessment document for hydroxypropyl guar, it was concluded that hydroxypropyl

guar is a high molecular weight polymer that is devoid of reactive functional groups

and which is not absorbed by any route of human exposure. It was also concluded that

there is no concern for potential sensitivity to infants and children. Based on results

from toxicological studies, structural similarities to guar gum, hydroxypropyl guar,

carboxymethyl guar, and carboxymethyl‐hydroxypropyl guar, as well as, its high

molecular weight and low likelihood of absorption via any route of exposure, there is

no reason to believe that adverse effects on the U.S. population will result from the

use of this inert ingredient in pesticide formulations. In addition, there is no reason to

believe that infants and children will be disproportionately at risk to the use of

cationic hydroxypropyl guar in pesticide formulations.

2. Infants and children. [NA‐Remove.]

F. International Tolerances

There are no known U.S. or international tolerances or tolerance exemptions

for cationic hydroxypropyl guar.