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EPA BIOPESTICIDES AND POLLUTION PREVENTION DIVISION 

COMPANY NOTICE OF FILING FOR PESTICIDE PETITIONS PUBLISHED IN 

THE FEDERAL REGISTER 

EPA Biopesticides and Pollution Prevention Division contact: Michael Glikes, 

703-305-6502

SUBMISSION: Email the completed template to: hollis.linda@epa.gov.

TEMPLATE:

Marrone Bio Innovations, Inc.

4F8271

EPA has received a pesticide petition 4F8271 from Marrone Bio Innovations, Inc. 

1540 Drew Avenue, Davis, CA 95618 requesting, 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

1. by establishing a tolerance for residues of NA-Remove

2. to establish an exemption from the requirement of a tolerance for

3. to establish an amendment/expansion of an existing tolerance exemption for the

NA-Remove

1. microbial pesticide sterile grain inoculated with Muscodor albus strain SA-13

2. biochemical pesticide NA-Remove

3. plant-pesticide NA-remove in or on NA-remove.

Pursuant to section 408(d)(2)(A)(i) of FFDCA, as amended, Marrone Bio Innovations, 

Inc. has submitted the following summary of information, data, and arguments in support 

of their pesticide petition. This summary was prepared by Marrone Bio Innovations, Inc.

and EPA has not fully evaluated the merits of the pesticide petition. The summary may

have been edited by EPA if the terminology used was unclear, the summary contained 

extraneous material, or the summary unintentionally made the reader conclude that the 

findings reflected EPA’s position and not the position of the petitioner.
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I. Marrone Bio Innovations, Inc. Petition Summary

4F8271

A. Product Name and Proposed Use Practices

Sterile grain inoculated with Muscodor albus strain SA-13 is the active ingredient in 

MBI-601 EP which is proposed for use as a soil treatment to control or suppress soil-borne plant 

diseases and plant parasitic nematodes and insects in horticultural and agricultural soils. When 

activated with moisture, sterile grain inoculated with Muscodor albus strain SA-13 produces 

volatile organic compounds that inhibit the growth or kill target pests. MBI-601 EP is 

incorporated into the soil before planting or applied in furrow post planting along the planting 

rows and watered in to activate the volatile compounds. 

B. Product Identity/Chemistry

1. Identity of the pesticide and corresponding residues. Muscodor albus strain SA13 is a naturally-occurring microbe originally isolated from the honey mesquite host plant in 

South Africa. Phylogenetic analysis of Muscodor albus strain SA-13 was performed by 

acquisition of the ITS-58S ribosomal gene sequence. The Muscodor albus strain SA-13 rRNA 

was compared with rRNAs from other Muscodor species and strains of M. albus. The ITS rRNA 

sequence had a high similarity with other isolates of M. albus and M. crispans. Muscodor albus 

strain SA-13 grows as a white sterile mycelium and does not produce spores or other reproductive 

structures. The active ingredient, sterile grain inoculated with Muscodor albus strain SA-13

works to inhibit or kill target pests by production of a number of volatiles. These volatiles are 

primarily simple alcohols and esters that are known natural and synthetic flavoring substances. 

Information regarding the name, identity and composition of MBI-601 EP and the volatiles 

released upon hydration has been submitted to EPA and can be found in MRID No. 493176-01. 

2. Magnitude of residues at the time of harvest and method used to determine the 

residue. Residues of sterile grain inoculated with Muscodor albus strain SA-13 are not expected 

on food or feed items because the active ingredient will not be in direct contact with treated 

commodities. The seven primary volatiles released by sterile grain inoculated with Muscodor

albus strain SA-13 were identified using GC/MS and are primarily simple alcohols and esters that 

are known natural and synthetic flavoring substances. When used as proposed, MBI-601 EP 

would not result in residues of sterile grain inoculated with Muscodor albus that are of 

toxicological concern.

3. A statement of why an analytical method of detecting and measuring the levels 

of the pesticide residue are not needed. An analytical method for detecting and measuring the 

levels of sterile grain inoculated with Muscodor albus strain SA-13 is not needed. Residues of 

sterile grain inoculated with Muscodor albus strain SA-13 are not expected on food or feed items 

because the active ingredient will not be in direct contact with treated commodities. There should 

be no residues of sterile grain inoculated with Muscodor albus strain SA-13 because the active 

ingredient has limited survivability once the nutrient source is exhausted. The primary volatiles 

produced by sterile grain inoculated with Muscodor albus strain SA-13 are simple alcohols and 

esters that are known natural and synthetic flavoring substances. An analytical method for 
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residues is not required for an exemption from tolerance because when used as proposed MBI601 EP would not result in residues of sterile grain inoculated with Muscodor albus that are of 

toxicological concern. The volatiles compounds that are produced by the active ingredient occur 

naturally or are known synthetic flavoring substances and dissipate rapidly in soil and water.

C. Mammalian Toxicological Profile

Acute Oral Toxicity (OCSPP 870.1100): MBI 601 EP was low in toxicity in an acute oral 

toxicity testing in albino rats following the up-and-down procedure (MRID No. 493176-06). 

Female albino rats received a gavage dose of 5,000 mg/kg of the test article and there were no 

clinical signs of toxicity. No mortality occurred during the 14-day observation period. The 

LD50 for MBI-601 EP was determined to be >5000 mg/kg body weight, classifying it as a 

Category IV substance for acute oral toxicity.

Acute Dermal Toxicity (OCSPP 870.1200): MBI 601 EP was not toxic in an acute dermal study 

conducted on albino rats (MRID No. 493176-07). Single undiluted doses of 5050 mg/kg body 

weight of the test article were applied to the intact skin of 10 albino rats and exposure was 

maintained for 24 hours. There was no mortality observed in the study. All male rats gained 

weight weekly, as did 2 of the females. Three females either lost or didn’t gain weight during the 

first or second week of the study. No abnormalities were identified in any of the rats in the gross 

necropsy at study termination. The LD50 for dermal exposure to MBI-601 EP is greater than 

5,050 mg/kg

Acute Inhalation Toxicity (OCSPP 870.1300: A mixture of the seven volatiles released by MBI 

601 EP was not toxic in an acute inhalation toxicity study conducted in rats (MRID No. 493176-

08). The potential for acute inhalation toxicity of the active volatiles released by MBI-601 EP was 

evaluated in 5 male and 5 female albino rats. Rats were exposed via inhalation to an atmosphere 

composed of the primary volatiles released by MBI-601 in nose-only chambers for four hours. 

No mortality occurred during or after exposure to a concentration of 5.28 mg/L volatiles. All 

exposed rats exhibited irregular respiration after the exposure, though they recovered and 

appeared active and healthy by day 3. All rats gained body weight from day 1 to 14, and no gross 

abnormalities were identified at the terminal necropsy. The LC50 for inhalation exposure to the 

active volatiles released by MBI-601 EP is greater than 5.28 mg/L.

Primary Dermal Irritation (OCSPP 870.2500: The results from an acute dermal irritation study 

(MRID No. 493176-10) demonstrate that MBI-601 EP is not a dermal irritant. In the acute 

dermal irritation study, single undiluted doses of 500 mg of MBI-601 EP were applied to the 

intact skin of 3 albino rats and moistened with 0.5 ml of water, then covered with a semipermeable dressing for 4 hours. Observations for possible dermal irritation were made at 1, 24, 

48 and 72 hours after exposure. Erythema and edema were not reported to occur during the 

observation period. This study supports an EPA Toxicity Category IV for primary dermal 

irritation.

Dermal Sensitization (OCSPP 870.2600): A skin sensitization study was conducted on 15 male 

and 15 female albino guinea pigs to determine if MBI- 601 EP elicited a sensitizing reaction 

(MRID No. 493176-11). Naive control group animals remained untreated during the induction 

phase of the study. Test group animals were treated with 400 mg of test substance moistened with 

0.4 mL of water. Test animals were treated once weekly for three weeks, for a total of three 

treatments. After a two-week rest period, all animals (both groups) were challenged at a virgin 

test site with an application of 400 mg test substance moistened with 0.4 mL of water. The test 

substance challenge produced no reaction in test animals or naïve control animals after the 
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challenge treatment, and therefore did not elicit a sensitizing reaction in guinea pigs. The MBI601 EP is not a sensitizer.

Acute Pulmonary Toxicity / Pathogenicity (OCSPP 885.3150): MBI-601 EP was not toxic or 

pathogenic and showed clearance following pulmonary exposure. An acute study was conducted 

to evaluate the pulmonary toxicity, pathogenicity and infectivity of MBI-601 EP following a 

single pulmonary dose of 0.3 ml / 100 g body weight (approximately 21.45 mg dry mycelial 

weight (DMW)/rat) (MRID No. 493176-05). Animals were observed daily for 21 days after 

dosing for mortality and signs of toxicity. Tissue and blood samples were collected at interim 

sacrifices to provide a quantitative record of the clearance pattern of the microbe. No behavioral 

or physical abnormalities were observed for any of the animals on study, and all necropsy 

samples were negative for any toxic or pathogenic effects due to exposure. All blood and tissue 

samples collected were considered clear of any test substance by day 3, given that quantification 

results on that day yielded two consecutive results below the clearance threshold. MBI-601 EP 

was determined to be non-toxic and non-pathogenic to rats following tracheal injection.

Sterile grain inoculated with Muscodor albus strain SA-13 produces volatile organic compounds 

that control or suppress soil-borne plant diseases and plant parasitic nematodes and insects. The 

volatile compounds occur naturally or are known synthetic flavoring substances. None of these 

compounds are toxic to humans.

D. Aggregate Exposure

i. Dietary exposure. Dietary exposure from use of MBI-601 EP is expected to be minimal 

based on the proposed use pattern of incorporation into the soil. The intended use of MBI 

601 EP is as a soil pest control agent. The application methods specified on the label for 

MBI-601 EP are intended to restrict treatment to target soils. The microbe is firmly 

attached to the sterile barley substrate that is covered with soil after application and has 

limited survivability once its carrier nutrient source is exhausted. For this application 

method, the poor survivability of the active ingredient will limit any dietary exposure and 

precludes dispersion to nontarget areas via drift, run-off or other mechanisms. The results 

of acute oral, dermal and pulmonary toxicity/pathogenicity testing indicates there is little 

if any risk to human health or the environment from exposure to sterile grain inoculated 

with Muscodor albus strain SA-13. There are no reports of ecological or human health 

hazards caused by sterile grain inoculated with Muscodor albus strain SA-13. The 

volatile compound released from sterile grain inoculated with Muscodor albus strain SA13 in the highest proportion at 30.6% is ethanol which is the alcohol in alcoholic 

beverages and a solvent exempt from tolerance as an inert ingredient in pesticides. The 

volatile released in the second highest proportion at 30.1% is 3-methyl-1-butanol, a 

naturally occurring flavoring component of fruits and vegetables. This flavor is present 

in apple juice from three different varieties (Fuji, Gala and Lisgala) at all stages of 

ripeness in concentrations from 0.66 to 7.27 mg/L (Braga et al., 2013). 3-methyl-1-

butanol has also been measured in tomatoes at concentrations from 0.4 to 1.5 mg/L 

(Ortiz-Serrano & Gil, 2010). The volatile released in the third highest proportion is 2-

methyl-1-butanol, which has been measured in young wines at levels of 0.048 to 0.14 

mg/L (Wondra & Berovic 2001). In the same wines, 3-methyl-1-butanol levels ranged 

from 0.126 to 0.482 mg/L. The remaining four volatiles, ethyl acetate, isobutanol, ethyl 

isobutyrate, and methyl isobutyrate make up 20% of the total released. These include: 1) 

inert ingredients exempt from tolerance (ethyl acetate, and isobutanol), and 2) FDA 

approved synthetic flavoring substances (21 CFR 172.515; isobutanol, ethyl isobutyrate 

and methyl isobutyrate. The results of acute toxicity and pathogenicity testing and the 
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current presence of the volatiles in the diets indicate there is little if any risk to human 

health from exposure to sterile grain inoculated with Muscodor albus strain SA-13. The 

absence of toxicity or pathogenicity in laboratory animals demonstrates the lack of 

toxicological concern for any incremental increase in dietary exposure from use of MBI601 EP.

ii. Food. Residues of sterile grain inoculated with Muscodor albus strain SA-13 are not 

expected on food or feed items because the active ingredient will not be in direct contact 

with treated commodities. The seven primary volatiles released by sterile grain inoculated 

with Muscodor albus strain SA-13 were identified using GC/MS and are primarily simple 

alcohols and esters that are known natural and synthetic flavoring substances. When used 

as proposed, MBI-601 EP would not result in residues of sterile grain inoculated with 

Muscodor albus that are of toxicological concern.

iii. Drinking water. Similarly, exposure to humans from residues of sterile grain 

inoculated with Muscodor albus strain SA-13 consumed in drinking water would be 

unlikely because the microbe is incorporated into soil attached to a sterile barley 

substrate. MBI-601 EP label instructions require that the product be incorporated into the 

soil for optimal performance, reducing any likelihood that sterile grain inoculated with 

Muscodor albus strain SA-13 would enter surface water (Mileson, 2014; MRID # 

493176-18). Further, sterile grain inoculated with Muscodor albus strain SA-13 has 

limited survivability once its carrier nutrient source is exhausted. This short life cycle 

minimizes the likelihood that sterile grain inoculated with Muscodor albus strain SA-13 

could leach through the soil and enter ground or drinking water in significant

iii. Non-dietary exposure. The potential for non-dietary exposure to the general 

population, including infants and children, is reasonably low given the primary uses are 

for agricultural and ornamental treatments, and residential uses are expected to be 

occasional or periodic. The intended use of MBI-601 EP is for application to soil to 

control or suppress soil-borne plant diseases. Sterile grain inoculated with Muscodor 

albus strain SA-13 has limited survivability once its carrier nutrient source is exhausted. 

Volatile compounds released from sterile grain inoculated with Muscodor albus strain 

SA-13 are not of toxicological concern and dissipate rapidly in the environment. Personal 

Protective Equipment (PPE) mitigates the potential for exposure to applicators and 

handlers of the proposed product when used in agricultural settings. Label mitigation 

measures are included on packaging for residential use, intended to minimize exposures 

to infants and children. In addition, the product is incorporated into the soil and not 

readily available for accidental exposure. 

E. Cumulative Effects

The Food Quality Protection Act of 1996 requires the EPA to consider the cumulative effects of 

chemicals with a common mechanism of toxicity in its tolerance assessment decisions. There is 

no indication that sterile grain inoculated with Muscodor albus strain SA-13, or the volatiles 

produced by sterile grain inoculated with Muscodor albus strain SA-13, act by a common 

mechanism of action with other compounds to result in any cumulative effects

F. Safety Determination

1. U.S. population. Acute toxicity studies have shown that sterile grain inoculated with 
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Muscodor albus strain SA-13 and the volatiles released upon rehydration are not toxic or 

irritating to mammals. These results indicate sterile grain inoculated with Muscodor albus strain 

SA-13 is not of toxicological concern for the general population when used as proposed on the 

label. Further, sterile grain inoculated with Muscodor albus strain SA-13 was not pathogenic or 

infective following tracheal injection, indicating that sterile grain inoculated with Muscodor albus

strain SA-13 is not of concern for pathogenicity or infectivity when used as proposed. Based on 

the data available, there is a reasonable certainty of no harm to the general US population from 

exposure to sterile grain inoculated with Muscodor albus strain SA-13.

2. Infants and children. As mentioned above, it is expected that, when used as proposed, 

sterile grain inoculated with Muscodor albus strain SA-13 would not result in residues that are of 

concern for potential toxicity or pathogenicity. Based on the data provided, there is a reasonable 

certainty of no harm for infants and children from exposure sterile grain inoculated with 

Muscodor albus strain SA-13 from the proposed uses.

G. Effects on the Immune and Endocrine Systems

To date there is no evidence to suggest that sterile grain inoculated with Muscodor albus

strain SA-13 functions in a manner similar to any known hormone, or that it acts as an endocrine 

disrupter.

H. Existing Tolerances

There is no US EPA tolerance or tolerance exemption for sterile grain inoculated with 

Muscodor albus strain SA-13.

I. International Tolerances

A Codex Alimentarium Commission Maximum Residue Level (MRL) is not established 

for sterile grain inoculated with Muscodor albus strain SA-13.