UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

MEMORANDUM 

DATE: September 10, 2014 

SUBJECT: Dikegulac Sodium. Human Health Scoping Document and Preliminary Risk 

Assessment. 

PC Code: 10960 1 DP Barcode: D421171 

Decision No.: 492549 Registration Nos.: 2217-932, 2217-776, 691 17-7 

Petition No.: NA Regulatory Action: Registration Review 

Case No.: Risk Assessment Type: Single Chemical 

TXRNo.: NA CAS No.: 52508-35-7 

MRIDNo.: NA 40 CFR: NA 

FROM: Bridgett 

Yung Yan

Bo

g, 

bowiec, 

Ph.D., T

Biologi

oxicologist 

st ~ 6--~ 7--cl 

P. 

Risk 

Yvonne 

Assessment 

Barnes, 

Branch 

Chemi

6 

st -,?.a ....,___ 6 ~ 

Health Effects Division (7509P) 

THROUGH: Shalu Shel~t, Indu_strial Hygieni~t ·~' ~~ Q 1 r. ~ Donna Dav1s, Actmg Branch Chief · (%lj~ ~\/ Y r7 

Risk Assessment Branch 6 

Health Effects Division (7509P) 

TO: Matthew Manupella, Chemical Review Manager 

Cathryn Britton, Team Leader 

Risk Management and Implementation Branch 

Pesticide Re-Evaluation Division (7508P) 

Page 1 of 12 
Executive Summary 

To determine the scope of work necessary to support Registration Review, Health Effects 

Division (HED) has considered updates to Agency's science policy and risk assessment 

methodologies and to the dikegulac sodium toxicity, exposure, and usage databases. 

Dikegulac sodium is a plant growth regulator. It is registered to control foliar growth and 

suppress nuisance fruiting for greenhouse and outdoor landscaping ornamentals, as well as for 

tree farms. There are no agricultural uses associated with dikegulac sodium. The current 

toxicology and exposure databases for dikegulac sodium are considered complete to support a 

non-food use registration. No residue chemistry data are required for a non-food use pesticide. 

The most recent dikegulac risk assessment took a qualitative approach to assessing risk, since 

this chemical does not pose a hazard at doses relevant to human exposure. 

Dikegulac sodium has low acute toxicity for oral, dermal, and inhalation toxicity (all Toxicity 

Categories IV). The primary eye irritation study (§81-4) is classified as Toxicity Category III. 

The chemical exhibits slight dermal irritation (Toxicity Category III) and is not a dermal 

sensitizer. No target organ toxicity is identified in dogs and rats following oral exposures and in 

rabbits following dermal exposures at doses including and up to the Limit Dose (2': 1,000 

mg/kg/day). The Hazard and Science Policy Council (HASPOC) waived the study requirements 

for subchronic inhalation, neurotoxicity (acute and subchronic), immunotoxicity, and 

reproduction studies since there is no evidence of neuro-, developmental, immuno-, or 

reproductive toxicity. Long-term rodent information regarding the chronic or carcinogenic 

potential of dikegulac sodium are not required for a non-food use chemical. There is no concern 

for mutagenicity. HED has concluded that dikegulac sodium does not pose a hazard at doses 

relevant to humans; therefore a qualitative risk assessment is appropriate for this chemical. 

There are no registered or proposed residential handler uses for dikegulac sodium. Occupational 

handler and post-application exposure as well as residential postapplication exposure are 

expected based on the registered use patterns, however, no endpoints of toxicological concern 

have been identified for risk assessment purposes since dikegulac sodium does not pose a human 

health hazard, there are no occupational risks or residential post-application risks associated with 

the registered use ofthis chemical. 

No new data are required to support the registration review of this pesticide. There are no 

hazards associated with dikegulac sodium at doses relevant to humans; therefore, a qualitative 

approach to risk assessment is appropriate. This document constitutes the preliminary risk 

assessment for the purpose of registration review. HED concludes that there are no human 

health risks associated with the currently registered uses of dikegulac sodium. 

Introduction 

HED has evaluated the status of the human health assessment for dikegulac sodium to determine 

whether sufficient data are available and whether any updates are needed to support Registration 

Review. HED has considered the most recent human health risk assessment for dikegulac 

sodium. While risk and exposure assessment policies have been updated since the last risk 

Page 2 of 12 
Page 3 of 12

assessment (DP317256, Y. Barnes, 10/31/2006 and addendum DP317852, S. Recore, 

02/06/2007), HED is not recommending a new risk assessment as part of registration review due 

to the qualitative approach taken to assess risk for dikegulac sodium

Dikegulac sodium is structurally similar to natural products involved in the synthesis or 

biosynthesis of L-ascorbic acid (vitamin C), naturally occurring plant cell wall components, and 

to naturally occurring carbohydrates. Dikegulac sodium is listed as a GRAS (Generally 

Recognized as Safe) chemical in 21 CFR §182 for use as a chemical preservative (§182.3013), a 

dietary supplement (§182.5013), and a nutrient (§182.8013). The chemical identity and 

physicochemical properties of dikegulac sodium are attached in Tables 1.

There are two end-use formulations for the growth regulator dikegulac sodium; soluble

concentrates (2217-776 and 2217-932) and a Ready-To-Use (RTU) formulation (69117-7). The 

soluble concentrate is applied to landscape ornamentals and to tree foliage using mechanically 

pressurized handgun, backpack sprayers, airblast, manual pressurized handwand, bark banding, 

and tree injection systems. The maximum application rates range from of 0.035 pounds active 

ingredient (ai) per gallon to 0.835 lb ai/gallon. The corresponding dikegulac sodium acid 

equivalent (ae) rate ranged from 0.035 lb ae/gallon to 0.77 lb ae/gallon. 

The current label for the soluble concentrate formulation of dikegulac sodium requires baseline 

dermal protection (long-sleeved shirt, long pants, shoes plus socks) and the addition of

waterproof gloves. The RTU injection product requires the same PPE plus the protective 

eyewear. The injection product contain a requirement for protective eyewear due to the nature of 

the application and not due to the acute toxicity of the active ingredient. Worker protective 

standard (WPS) language for early entry includes coveralls, shoes, socks, chemical-resistant 

gloves (of any waterproof material), and protective eyewear. 

Most recently, there was a registrant request reviewed which petitioned the Agency to reduce the

12 hour restricted entry interval (REI) which is based on the acute toxicity of the chemical. HED 

determined that the registrant would need to supply EPA with specific information about the end 

use product containing dikegulac sodium to qualify for a reduced 4-hour REI requirement. The 

REI remains 12 hours pending registrant submission of end use product hypersensitivity, adverse 

health effects, and incident information (D370143, A. Nielson, 02/04/2010).

Hazard Identification/Toxicology

The available toxicological data for dikegulac sodium are sufficient for hazard assessment. All 

submitted studies are detailed in the attached toxicology tables (Table 3 through 5).The database 

consists of acute toxicity battery, developmental toxicity studies in rats and rabbits, subchronic 

(oral) toxicity studies in dogs and rats, and a 21-day dermal toxicity study in rabbits. 

Mutagenicity studies are available include Salmonella typhimurium, micronucleus, and gene 

mutation assays. The HASPOC considered all of the available hazard and exposure information 

for dikegulac sodium and concluded that data requirements for subchronic inhalation toxicity, 

reproduction, neurotoxicity (acute and subchronic), and immunotoxicity studies are waived at 

this time (U. Habiba, TXR 0057022, 07/31/2014). Since it is a non-food use chemical, submitted 
Page 4 of 12

toxicity studies in combination of published literature are sufficient to assess the toxicity of 

dikegulac sodium.

The available acute toxicity studies indicate that dikegulac sodium has very low oral, dermal and 

inhalation toxicity (Toxicity Categories IV). In July, 2008, EPA reclassified the primary eye 

irritation study (§81-4) from Toxicity Category II to Toxicity Category III based on provided 

supporting documents and a re-evaluation of the submitted Dikegulac sodium exhibited slight 

dermal irritation (Toxicity Category III) and is not a skin sensitizer.

Acceptable/Guideline oral subchronic toxicity studies were conducted in dogs and rats. A 90-

day rat subchronic study revealed no toxicity, the NOAEL is ≥ 2,000 mg/kg/day with no LOAEL 

being established. In a 13-week dog toxicity study, beagle dogs were dosed at 0, 500, 1200 (via 

gelatin capsules), or 3000 mg/kg/day (via stomach tubes), diarrhea (presumable caused 

osmotically) was observed in the first week of treatment and especially in the high dose groups 

(1200 and 3000 mg/kg/day). However, this had no effect on the weight development of the dogs.

The NOAEL is 1,200 mg/kg/day and the LOAEL is 3,000 mg/kg/day based on the relatively 

mild effects of profuse watery diarrhea and occasional vomiting. 

A rat developmental toxicity study revealed no developmental or embryotoxic effects based on 

fetal and maternal parameters. The maternal NOAEL is 700 mg/kg/day and the LOAEL is 2,000 

mg/kg/day, based on clinical observations of light sedation following the first two treatments. 

The developmental NOAEL is > 2,000 mg/kg/day with no LOAEL being established. In a rabbit 

developmental study, no treatment-related developmental or embryotoxic effects were seen

based on maternal clinical signs, liver enzymes, liver weights, gross pathology, litter size, 

numbers of live fetuses, dead fetuses, or resorptions, post implantation loss, sex ratio, fetal 

weight, or placental weight. The maternal NOAEL is 700 mg/kg/day and the LOAEL is 2,000 

mg/kg/day, based on clinical observations of diarrhea and lack of body weight gain. The 

developmental NOAEL is > 2,000 mg/kg/day with no LOAEL being established.

A 21-day dermal toxicity study in rabbits resulted in slight erythema. However, no compoundrelated effects on mortality, body weight, body weight gain, food consumption, hematology, 

ophthalmology, or gross pathology were observed in the females. The dermal NOAEL is 600 

mg/kg/day with no LOAEL being established.

Available genotoxicity and mutagenicity studies were negative for reverse gene mutations in 

Salmonella typhimurium, not mutagenic in mouse lymphoma cell assays with/without activation 

at levels ranging from 500 to 5,000 μg/ mL, and negative for micronucleus induction in bone 

marrow cells of male and female CD-1 mice harvested 24, 48, and 72 hours post-administration 

of a single dose of 1,250, 2,500 or 5,000 mg/kg. For a non-food use chemical, no long-term 

rodent information regarding the carcinogenic potential of dikegulac sodium is required.

Based on the available data, there is no evidence to suggest that dikegulac sodium causes 

increased susceptibility in infants and children. Furthermore, based on the low hazard concern 

from the available studies, no endpoints of toxicological concern have been identified for risk 

assessment purposes. 
Page 5 of 12

Dietary Exposure

Dikegulac sodium does not have any agricultural or food production uses, as such it is designated 

and classified as a “non-food” use chemical. Based on the low hazard concern from the 

available studies, no endpoints of toxicological concern have been identified. Due to the hazard 

profile drinking water assessments are not needed. In addition, because dikegulac sodium is not 

used on any agricultural food and/or feed commodities and is classified as a “non-food” use 

chemical and metabolized to non-toxic substances; a dietary risk assessment is not required.

Residential Exposure

Dikegulac sodium is used in small quantities by the professional landscaping industry, and is not 

marketed to homeowners. Residential post application exposure is possible from occupational 

application to residential use sites however, due to the (very) low systemic toxicity of dikegulac 

sodium, a residential quantitative risk assessment is not warranted for any type, or duration of 

exposure. 

Spray Drift and Volatility

Since dikegulac does not pose a hazard, there are no risks associated with potential exposure to 

spray drift or exposure from volatility expected from this chemical.

Occupational Exposure

Dikegulac sodium is registered for use as two end-use product formulations (soluble concentrate 

and RTU injections). Table 6 summarizes the occupational handler use patterns and potential 

exposure scenarios. While there are uses that could result in occupational handler and postapplication exposure, due to the (very) low systemic toxicity of dikegulac sodium, a quantitative

occupational risk assessment is not warranted for any type, or duration of exposure. 

Turf Transferable Residue (TTR) and Dislodgeable Foliar Residue (DFR) data are not required 

for dikegulac sodium based on the current use patterns for this chemical. 

Public Health and Pesticide Epidemiology Data

Because there are no incident cases reported for dikegulac sodium in either the Main or 

Aggregate Incident Data System (IDS) module, Poison Control Centers (PCCs), California 

Department of Pesticide Regulation, National Pesticide Information Center(NPIC) and National 

Institute of Occupational Safety and Health’s Sentinel Event Notification System for 

Occupational Risks (NIOSH SENSOR) there does not appear to be a concern at this time that 

would warrant further investigation (D317857, M. Hawkins, 07/25/2006). 

Environmental Justice

Potential areas of environmental justice concerns, to the extent possible, were considered in this 

human health risk assessment, in accordance with U.S. Executive Order 12898, "Federal Actions 

to Address Environmental Justice in Minority Populations and Low-Income Populations," 

(http://www.eh.doe.gov/oepa/guidance/justice/eo12898.pdf). As a part of every pesticide risk 
Page 6 of 12

assessment, OPP considers a large variety of consumer subgroups according to well-established 

procedures. In line with OPP policy, HED estimates risks to population subgroups from 

pesticide exposures that are based on patterns of that subgroup’s food and water consumption, 

and activities in and around the home that involve pesticide use in a residential setting. 

Extensive data on food consumption patterns are compiled by the United States Department of 

Agriculture’s (USDA’s) National Health and Nutrition Examination Survey (NHANES), What 

We Eat in America (NHANES/WWEIA) and are used in pesticide risk assessments for all 

registered food uses of a pesticide. These data are analyzed and categorized by subgroups based 

on age and ethnic group. Additionally, OPP is able to assess dietary exposure to smaller, 

specialized subgroups and exposure assessments are performed when conditions or 

circumstances warrant. Whenever appropriate, non-dietary exposures based on home use of 

pesticide products and associated risks for adult applicators and for children, youths, and adults 

entering or playing on treated areas following application are evaluated. Further considerations 

are currently in development as OPP has committed resources and expertise to the development 

of specialized software and models that consider exposure to bystanders and farm workers as 

well as lifestyle and traditional dietary patterns among specific subgroups.

Cumulative

Unlike other pesticides for which EPA has followed a cumulative risk approach based on a 

common mechanism of toxicity, EPA has not made a common mechanism of toxicity finding as 

to dikegulac sodium and any other substances. Dikegulac sodium does not appear to produce a 

toxic metabolite produced by other substances. For the purposes of this tolerance action, 

therefore, EPA has not assumed that dikegulac sodium has a common mechanism of toxicity 

with other substances. For information regarding EPA’s efforts to determine which chemicals 

have a common mechanism of toxicity and to evaluate the cumulative effects of such chemicals, 

see the policy statements released by EPA’s OPP concerning common mechanism 

determinations and procedures for cumulating effects from substances found to have a common 

mechanism on EPA’s website at http://www.epa.gov/pesticides/cumulative/.

Human Studies

This assessment does not rely on any data from studies in which human subjects were 

intentionally exposed to a pesticide. 

Data Requirements

Residue chemistry data are not required for a non-food use chemical however the UV/visible 

absorption spectrum study is still outstanding. There are no outstanding toxicological or 

exposure data requirements for the currently registered uses of dikegulac sodium.

Preliminary Human Health Risk Assessment

The qualitative assessment discussed herein constitutes the preliminary risk assessment for 

dikegulac sodium. HED concludes that there are no human health risks associated with the 

currently registered uses of dikegulac sodium. 
Page 7 of 12

References

Memoranda Relevant to Registration Review for Dikegulac Sodium

Author DP or TXR 

Barcode Date Title

Y. Barnes D317256 10/31/2006

Dikegulac Sodium. Human Health 

Considerations for the Reregistration Eligibility 

Decision

S. Recore D317852 02/06/2007 Dikegulac Sodium: Addendum to HED Risk 

Assessment

U. Habiba TXR 0057022 07/31/2014

Dikegulac Sodium: Summary of Hazard and 

Science Policy Council (HASPOC): subchronic

inhalation, neurotoxicity (acute and 

subchronic), reproduction, and immunotoxicity 

studies.

M. Hawkins D317857 07/25/2006 Review of Dikegulac Sodium Incident Reports

A. Nielsen D370143 02/04/2010

Dikegulac Sodium: HED’s response to 

PBI/Gordon Corporation’s request to permit a 

4-hour restricted entry interval for the end use 

product Atrinal Plant Growth Regulator (EPA 

Reg. No. 2217-776)

S. Recore D317852 02/06/2007 Dikegulac Sodium: Addendum to HED Risk 

Assessment Acid Equivalent Rates

Attachments

Table 1. Chemical Identity of Dikegulac Sodium

Table 2. Physicochemical Properties of Technical Grade Dikegulac Sodium

Table 3. Satisfaction of Dikegulac Sodium Toxicology Data Requirements

Table 4. Dikegulac Sodium Acute Toxicity Profile

Table 5. Dikegulac Sodium Subchronic, Chronic, and Other Toxicity Profiles

Table 6. Summary of Representative Occupational Use Patterns, Formulations, and App Rates
Page 8 of 12

Attachments

Chemical Identity and Physicochemical Properties Tables

Table 1. Chemical Identity of Dikegulac Sodium

Chemical Structure

Common Name Dikegulac Sodium

PC Code 109601

CAS Name sodium 2,3:4,6-bis-O-(1-methylethylidene)-α-L-xylo-2-hexulofuranosonate

IUPAC Name sodium 2,3:4,6-di-O-isopropylidene-α-L-xylo-2-hexulofuranosonate

CAS No. 52508 - 35 – 7

Registration Review Case No. 3061

Chemical Class` Acid herbicide

Molecular weight 235.02 g/mol

Table 2. Physicochemical Properties of Technical Grade Dikegulac Sodium

Parameter Value Reference

Molecular Weight 296.25 grams MSDS

Melting range > 300 oC MSDS

Density 9.12 lbs/gal MSDS

Water solubility (20°C) 590 g/L, soluble Merck Index 12th Edition

Solvent solubility (20°C)

methanol 390 g/L ; ethanol 230 g/L ; 

chloroform 60 g/L ; acetone <10 g/L ; 

hexane <10 g/L; cyclohexanone <10 g/L

Merck Index 12th Edition

Vapor pressure 3.08E-12 mm Hg at 25 °C 

SRC: Neely, WB & Blau, 

GE (1985)

Dissociation constant, pKa Not reported Data Required

Octanol/water partition coefficient, log KOW

(25°C) Log P = -2.05 SRC: Meylan, Wm. Howard ,PH (1995)

UV/visible absorption spectrum Not reported Data Required
Page 9 of 12

Table 3. Toxicology Data Requirements for Dikegulac Sodium

Study Technical

Required Satisfied

870.1100 Acute Oral Toxicity

870.1200 Acute Dermal Toxicity

870.1300 Acute Inhalation Toxicity

870.2400 Acute Eye Irritation

870.2500 Acute Dermal Irritation

870.2600 Skin Sensitization

yes

yes

yes

yes

yes

yes

yes

yes

yes

yes

yes

yes

870.3100 90-Day Oral Toxicity in Rodents

870.3150 90-Day Oral Toxicity in Non-Rodents

870.3200 21/28-Day Dermal Toxicity

870.3250 90-Day Dermal Toxicity

870.3465 90-Day Inhalation Toxicity

yes

CRa

yes

CRa(no)

CRa(yes)

yes

yes

yes

---

waivedb

870.3700 Prenatal Developmental Toxicity Study (Rodent)

870.3700 Prenatal Developmental Toxicity Study (Non-Rodent)

870.3800 Reproduction and Fertility Effects

yes

yes

yes

yes

yes

waivedb

870.4100 Chronic Toxicity (Rodent)

870.4200 Carcinogenicity (Two Rodent Species; Rat and Mouse)

870.4300 Combined Chronic Toxicity/Carcinogenicity

CRa(no)

CRa(no)

---

yes

yes

---

870.5100 Bacterial Reverse Mutation Test yes yes

870.5300 in vitro Mammalian Cell Gene Mutation Test

870.5375 in vitro Mammalian Chromosome Aberration Test

870.5385 Mammalian Bone Marrow Chromosomal Aberration Test

870.5395 Mammalian Erythrocyte Micronucleus Test

yes

yes

yes

yes

yes

yes

yes

yes

870.6200 Neurotoxicity Screening Battery (Acute, Rat)

870.6200 Neurotoxicity Screening Battery (Subchronic, Rat)

870.6300 Developmental Neurotoxicity Study

yes

yes

CRa(no)

waivedb

waivedb

---

870.7200 Companion Animal Safety

870.7485 Metabolism and Pharmacokinetics

870.7600 Dermal Penetration

870.7800 Immunotoxicity

CRa(no)

CRa(no)

CRa(no)

yes

---

yes

---

waivedb

a CR = conditionally required.

b Waived by Hazard and Science Policy Council (HASPOC) on (TXR).
Page 10 of 12

Table 4. Acute Toxicity Data for Dikegulac Sodium

Guideline 

No. Study Type MRID Results Toxicity Category

870.1100

81-1

Acute oral [rat]

Acceptable/guideline

44093901

No deaths, no clinical signs

LD50 >5000 mg/kg. IV

Acute oral [rat] 

Unacceptable/guideline

43064604

43064605

43064606

43064607

43064608

870.1200

81-2

Acute dermal [rat]

Acceptable/guideline

43064612 3 deaths, no clinical signs LD50 >2000 mg/kg III

Acute dermal [rabbit]

Acceptable/guideline

43064610 LD50 >1000 mg/kg II

44093902 No deaths, no clinical signs. LD50 >5000 mg/kg IV

870.1300

81-3

Acute inhalation [rat]

Acceptable/guideline

43064613

No deaths. LC50 >2 mg/L

III

44093903 IV

870.2400

81-4

Acute eye irritation [rabbit]

Acceptable/guideline

43064614 Conjunctival redness was persistent for 48 and 72 hours. IV

44093904

No corneal effects were observed. Conjunctival redness, swelling or 

discharge returned to normal within 72 hours. III

a

870.2500

81-5

Acute dermal irritation [rabbit]

Unacceptable/guideline

43064615

Slight dermal irritation/ slight erythema was apparent 72 hours after 

application III

Acute dermal irritation [rabbit]

Acceptable/guideline

44093905 Slight erythema and edema observed IV

870.2600

81-6

Acute dermal sensitization [guinea 

pig]

Unacceptable/guideline

43064616 All animals survived. No adverse clinical signs. Not a dermal sensitizer N/A

870.2600

81-6

Acute dermal sensitization [guinea 

pig]

Acceptable/guideline

44093906 All animals survived. No adverse clinical signs. Not a dermal sensitizer N/A

870.2500

81-5

Acute dermal irritation [rabbit]

Acceptable/guideline

44093905 Slight erythema and edema observed IV

870.2600

81-6

Acute dermal sensitization [guinea 

pig]

Unacceptable/guideline

43064616 All animals survived. No adverse clinical signs. Not a dermal sensitizer N/A

870.2600

81-6

Acute dermal sensitization [guinea 

pig]

Acceptable/guideline

44093906 All animals survived. No adverse clinical signs. Not a dermal sensitizer N/A

a The toxicity category on eye irritation was revised to III (TXR 0054936, 2008)
Page 11 of 12

Table 5: Subchronic, Developmental, and Other Toxicity Profile on Dikegulac Sodium

Guideline#/ Study 

Type MRID# (year)/ Classification /Doses Results

870.3100

82-1a

90-Day Subchronic 

toxicity (rat)

42957701 (1975)

Acceptable/guideline

22 Fullinsdorf albino rats/sex/dose of 0, 200, 

700, 2000 mg/kg/day for 13 weeks

Mortality, clinical signs, food consumption, body weight, 

hematology, urinalysis, organ weights, gross and microscopic 

pathology were unaffected by treatment. 

The NOAEL is ≥ 2000 mg/kg/day. The LOAEL was not 

established. 

870.3100

82-1b

90-Day Subchronic 

toxicity (dog)

42957702 (1975)

Acceptable/guideline

4 beagle dog sex/dose of 0, 500, 1200, 3000

mg/kg bw/day for 13 weeks

Mortality, clinical signs, body weight, hematology, urinalysis, 

organ weights, gross and microscopic pathology were 

unaffected by treatment.

The NOAEL is 1200 mg/kg/day. The LOAEL is 3000 

mg/kg/day based on relatively mild effects of profuse watery 

diarrhea and occasional vomiting. 

870.3250

82-3

21-Day dermal 

toxicity

42957703 (1975)

Acceptable/Guideline

5 New Zealand White rabbits/sex/ dose of 0, 

3% or 30% seven days a week for 21 days.

Slight erythema occurred in three male and three female 

control rabbits during the treatment period. 

The dermal NOAEL is 600 mg/kg/day, no LOAEL being 

established.

870.3700a

83-3a

Developmental 

Toxicity (rat)

43064617 (1977) 

Acceptable/Guideline

40 female Fullinsdorf albino rats/dose of (by 

gavage) 0, 200, 700 or 2000 mg a.i./kg/day

(GD 7-16)

The maternal NOAEL is 700 mg/kg/day.

The maternal LOAEL is 2000mg/kg/day, based on clinical 

observations of light sedation following the first two 

treatments. 

The developmental NOAEL is > 2000 mg/kg bw/day. 

No developmental LOAEL was established.

870.3700a

83-3a

Developmental 

Toxicity (rabbit)

43064618 (1977)

Acceptable/Guideline

20 female yellow-sliver rabbits/dose of 0, 

200, 700 or 2000 mg a.i./kg/day

(GD 7-19)

The maternal NOAEL is 700 mg/kg/day. 

The maternal LOAEL is 2000 mg/kg /day, based on clinical 

observations of diarrhea and lack of body weight gain. 

The developmental NOAEL is > 2000 mg/kg /day.

No developmental LOAEL was observed.

Gene Mutation

84-2

870.5100

(Salmonella 

typhimurium)

440393907 (1995)

Acceptable/Guideline

100, 333, 1000, 3330 and 5000 μg/ plate

Negative for reverse gene mutations in Salmonella 

typhimurium TA98, TA100, TA1535 and TA1537 in presence 

or absence of S9 activation to doses from 100 to 5000 

μg/plate. Cytotoxicity was not observed at any dose levels. 

Gene Mutation

870.5300 

84-2

(mouse lymphoma 

cells)

440393908 (1995)

Acceptable/Guideline

500 to 5000 μg/mL

Not mutagenic in assays with/without S9activation. 

Cytotoxicity was not observed at any dose levels.

Micronucleus

870.5395

84-2

(mouse)

440393909 (1995)

Acceptable/Guideline

1250, 2500, or 5000 mg/kg

Negative for micronucleus induction in bone marrow cells of 

Male and Female CD-1 mice harvested 24, 48, and 72 hrs. 

post-administration of single doses of 1250, 2500, or 5000 

mg/kg/day. No overt toxicity in any treated animal or target 

organ in any treatment group.
Page 12 of 12

Occupational Exposure Use Pattern Table

Table 6. Summary of Maximum Application Rates for Registered Dikegulac-Sodium Uses

EPA Reg. No Crop Target % ai.

Maximum 

Application 

Rate

Application 

Equipment 

Amount 

Handled 

Daily

Use Directions and Limitations 

Soluble Concentrate

ATRINAL® 

NURSERY 

AND 

GREENHOUSE

2217-932

Greenhouse 

and nursery 

ornamentals, 

tree farms

(chemical 

pinching)

Foliar 

Spray, 

bark 

banding, 

soil 

drench

18.5 %

0.052 lb 

ai/gallon

(0.048 lb 

ae1/gallon)

Mechanically 

pressurized 

handgun

1,000 

gallons

Not for use on green ash, red oak, conifers, 

trailing and weeping lantana, Christmas tree 

farms, and evergreens in California. Do not 

apply through any type of irrigation system. Do 

not use on food or fodder crops. PPE includes 

baseline dermal protection. Direct injections to 

trees, applicators must wear protective eyewear

Manually 

pressurized 

handwand

40

gallons

Backpack

ATRINAL® 

PLANT 

GROWTH 

REGULATOR

2217-776

Landscape 

Ornamentals 

-- shrubs, 

hedges, trees, 

and 

groundcover 

(growth 

control)

4.26 lb 

ai/A 

or 

0.039 lb 

ai/gallon

(0.035 lb 

ae/gallon)

Mechanically 

pressurized 

handgun

1,000 

gallons

Manually 

pressurized 

handwand 40 

gallons

Backpack

Use with medium or coarser spray nozzles. Do 

not apply through any type of irrigation system.

Do not use on food or fodder crops. PPE 

includes baseline dermal protection. Direct 

injections to trees, applicators must wear 

protective eyewear

Fruiting 

Landscape 

Trees and 

Shrubs 

(suppression 

of flower and 

fruit 

formation)

7.1 lb ai/A 

or 

0.065 lb 

ai/gallon

(0.060 lb 

ae/gallon)

Handgun 1,000 

gallons

Manually 

pressurized 

handwand 40 

gallons

Backpack

Broadleaf 

trees in 

rights-ofway, parks

Tree 

injection

0.09 lbs 

a.i./tree or 

0.835 lb 

ai/gallon

(0.77 lb 

ae/gallon)

Injection 

system NA

Ready to Use

Pinscher® PGR

69117-7

Ornamental 

trees

Tree 

injection 18.5 % 0.0016 lb a.i./ tree

Injection 

system NA Apply in spring prior to flower. Do not apply to foo bearing plants

1 ae= acid equivalent.