Proposed Registration of Furfural 

 on Golf Courses (Greens and Tees) 

 and Sod Farms for the Control 

 of Root Infesting Plant Parasitic Nematodes 

 and Certain Fungal Diseases 

 

May 21, 2010 

U.S. Environmental Protection Agency 

Office of Pesticide Programs 

Registration Division 

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Proposed Registration of Furfural Use on Golf Courses (Greens and Tees) and Sod Farms 

for the Control of Parasitic Nematodes and Certain Fungal Diseases 

REGULATORY PROPOSAL

 The U.S. Environmental Protection Agency, hereon referred to as EPA or the Agency, is 

proposing to register uses of the active ingredient, furfural, formulated as a flowable concentrate 

end-use product (Multiguard® Protect) for soil treatment of golf courses (greens and tees) and 

sod farms, under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), as amended. 

Based on the high volatility of furfural in the environment after an application, and the potential 

for high inhalation exposure concerns, the Agency determined it was appropriate to assess and 

require mitigation measures consistent with the process for soil fumigants. There are no 

registered food uses for furfural. 

I. INTRODUCTION 

 Furfural is currently registered for use on ornamentals in enclosed greenhouses to control 

root-infesting plant parasitic nematodes and certain fungal diseases, including Phythium, 

Phytophthora, Fusarium, and Rhizoctonia. It is a colorless, oily liquid with an almond-like odor. 

Furfural’s mode of action is reported to destroy the nematode cuticle, causing it to die by 

dehydration. Furfural has a vapor pressure of 2.6 mm Hg, which is considered to be highly 

volatile relative to typical pesticides. 

 Furfural is a naturally-occurring compound that is ubiquitous in the environment, with 

greater concentrations found in various agricultural plant matter byproducts, such as corn cobs, 

oat husks and bran, sawdust, and sugar cane bagasse. Furfural is currently used as a flavoring 

ingredient, as well as in industrial applications, including use as a solvent in petrochemical 

refining, and to produce solid resins such as fiberglass. Furfural is considered Generally 

Recognized as Safe by the Flavor and Extract Manufacturers’ Association, regarding its use as a 

flavoring agent; dietary intake of natural sources of furfural are significantly higher than 

exposure sources from use as a flavoring agent.

Given the unique fumigant-like properties (i.e., high volatility potential after application), 

the Agency determined that it is most appropriate to assess and regulate furfural on the basis that 

furfural’s behavior in the environment is similar to that of the soil fumigants. Therefore, similar 

mitigation measures are necessary to reduce risks from acute inhalation exposure to handlers, 

other workers, and bystanders. The Agency has required fumigant labels to instruct users to 

establish buffer zones for certain time durations around treated areas to reduce acute inhalation 

exposures. The buffer zone is a distance around the perimeter of the treatment area, measured 

from the edge of the treatment block, where entry into the treated area and its buffer zone is 

prohibited for the duration that the buffer zone is in place. A buffer zone is necessary for 

furfural because its exposure profile is similar to that of soil fumigants. Establishing buffer 

zones in order to reduce acute exposures are also protective of potential systemic effects. 

Therefore, the Agency is proposing the addition of labeling language to include the 

establishment of buffer zones around the treated areas, and environmental hazard statements to 

reduce the potential for off-site movement of furfural. 
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II. HUMAN HEALTH RISK ASSESSMENT

 EPA evaluated the potential human health risk for exposures to furfural-treated golf 

course turf and sod farms. The following information is a summary of the human health 

exposure and risk assessment for the proposed golf course and sod farm uses of furfural. For 

additional information, refer to the Agency’s document Furfural. Human Health Risk 

Assessment for Use on Golf Course Tees (Tees and Greens) and Sod Farms, dated February 18, 

2010. 

Given the high application rate of furfural and the potential for transport residues into 

drinking water sources, the Agency also conducted acute and chronic exposure dietary 

assessment (drinking water only) to determine if dietary exposures would pose any concern. For 

acute and chronic assessments, risk is expressed as a percentage of a maximum dose (i.e., the 

dose which EPA has concluded will result in unreasonable adverse health effects). 

 The Agency uses the term Margin of Exposure (MOE) to refer to the risk associated with 

the exposure estimate. The MOE is defined as: the dose, typically the No Observed Adverse 

Effects Level (NOAEL), divided by the estimated amount of human exposure. For example, an 

MOE of 100 means that the estimated level of human exposure is 100 times lower than the 

highest tested dose that produced no adverse effects in the relevant toxicology study. The greater 

the MOE, the lower potential for risk to humans from exposures. 

Based on the proposed use patterns, inhalation exposure to furfural is possible for 

workers who handle and apply furfural, as well as individuals living or working nearby an 

application site because of the higher volatility potential of furfural. To calculate potential 

inhalation exposure, the air concentration was estimated using modeling estimates (from the 

Probabilistic Exposure and Risk model for Fumigants (PERFUM)) based on field volatility data. 

Human-equivalent concentrations (HEC) from the available inhalation study were calculated 

using the reference concentration methodologies, which incorporates some pharmacokinetic 

differences for interspecies extrapolation. These HECs were then used to calculate margins of 

exposure (MOE). 

Dermal exposures were estimated based on a dislodgeable foliar residue study and 

standard assumptions, and then compared to the No Observed Adverse Effect Level (NOAEL) 

from a dermal study. Post-application dermal exposure may occur for individuals who enter 

areas in a golf course after furfural has been applied. Occupational post-application dermal 

exposures can also occur for those who harvest or otherwise handle treated sod. 

A. Toxicological End Points 

Acute Dietary Exposure: The acute reference dose (aRfD) of 0.01 mg/kg/day is 

derived from the NOAEL of 10 mg/kg/day based on clinical signs of toxicity at the 

maternal LOAEL of 50 mg/kg/day in the rat developmental toxicity study. In this 

study, dams exhibited clinical signs one hour post dosing and during subsequent 

dialing examinations. In the 28-day dermal toxicity study conducted on rabbits, there 

were indications of potential neurotoxicity, but was not considered severe. Without 
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neurotoxicity studies to better characterize the neurotoxicity potential of furfural, the 

Agency applied an additional 10X database uncertainty factor to account for this 

uncertainty. A 1,000-fold uncertainty factor was applied to estimating acute dietary 

risk based on 10X inter-species extrapolation, 10X intra-species variability, and an 

additional 10X safety factor due to the limited oral database. 

Chronic Dietary Exposure: The chronic reference dose (cRfD) of 0.01 mg/kg/day 

is derived from the 2-year carcinogenicity study in the rat, based on liver pathological 

observations observed at the LOAEL of 30 mg/kg/day. A 3,000-fold uncertainty 

factor (10X inter-species extrapolation, 10X intra-species variability, 30X due to the 

lack of NOAEL and limited oral database) was applied. 

Short- and Intermediate-Term Dermal Exposure. A rat dermal toxicity study was 

used to select the dose and endpoint for assessing risk due to short- and intermediateterm dermal exposures. For this study, the NOAEL of 250 mg/kg/day is based on 

adverse clinical signs, an increase in motor activity, and increased mortality at the 

LOAEL of 500 mg/kg/day. The MOE for short- and intermediate-term dermal 

exposure to furfural is 100 for occupational exposure (10X inter-species 

extrapolation, 10X intra-species variability) and 1,000 for non-occupational exposure 

(additional 10X due to the lack of reproduction study to evaluate susceptibility in 

children). Long-term exposure is not expected from the proposed use pattern. 

Acute, Short-, and Intermediate-term Inhalation Bystander (Nonoccupational) 

Exposure. To calculate the potential acute inhalation bystander exposure after a 

furfural application, the Agency estimated an HEC of 0.33 mg/m3

 as the 

concentration of concern, based on the incidence of nasal irritation effects in the 

repeat inhalation toxicity study. To calculate the short- and intermediate-term 

inhalation bystander exposure after a furfural application, the Agency estimated an 

HEC of 0.24 mg/m3. The Agency also applied an uncertainty factor of 30, which is 

based on 3X for inter-species extrapolation (reduced from 10X because EPA’s RfC 

methodology incorporates some pharmacokinetic differences between rats and 

humans), and 10X for intra-species variability). The uncertainty factor is applied to 

the HEC to define the air concentration of concern (COC). 

Buffer zones were estimated for six meteorological regions for several field sizes 

ranging from a half-acre to 80 acres to reflect exposures from applications to golfcourses to the larger sod farm acreages. Because it is possible for a bystander to be 

near the treated field at anytime, the HEC was adjusted to account for potential 

exposure that can occur over a 24-hour period. For all inhalation exposure scenarios, 

the target MOE is 30. Long-term exposure is not expected from the proposed use 

pattern. 

Acute, Short- and Intermediate-term Inhalation Occupational Exposure. To 

calculate the potential inhalation occupational exposure for acute, short-, and 

intermediate-term durations, the Agency estimated an HEC of 0.99 mg/m3

, based on 

the incidence of nasal irritation effects in the repeat inhalation toxicity study. The 
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HEC was adjusted to account for potential exposure that could occur during an 8-hour 

workday duration. 

Similar to the bystander assessment, postapplication inhalation exposure to furfural 

can occur for workers, e.g., if harvesting sod from a recently-treated area, or nearby a 

furfural application. Because the results of the bystander assessment are considered 

protective of occupational postapplication inhalation exposure, bystander buffer 

zones were used to represent occupational buffer zones. For all inhalation exposure 

scenarios, the target MOE is 30. Long-term exposure is not expected from the 

proposed use pattern. 

Cancer. The Agency has not classified the human carcinogenic potential of furfural 

at this time. Available information includes carcinogenicity studies conducted by the 

National Toxicity Program (NTP). Based on the tumor responses in these studies, 

NTP characterized the results as clear evidence of carcinogenic activity in male mice, 

some evidence in female mice and male rats and no evidence in female rats. The 

classification of furfural’s human carcinogenicity potential may be considered by the 

Agency if additional uses result in higher exposure. Therefore, a cancer risk 

assessment was not conducted at this time. 

B. Dietary Exposure 

The current proposed use pattern is for turf applications only, and the use of furfural is 

considered a non-food use. However, because of the high application rate of furfural, and the 

large amounts of water used during and after application, there is the potential for furfural 

residues to move into drinking water sources. Therefore to be health protective, the Agency 

conducted a dietary assessment (acute and chronic exposures) for drinking water. 

Furfural residues in drinking water were estimated to be significant lower than natural 

background sources, which were estimated to be approximately 0.3 mg/kg/day; the highest 

furfural concentrations found in cocoa or coffee can be as high as 255 mg/kg. The maximum 

acute dietary exposure (water only) from the proposed use of furfural was estimated to be 0.059 

mg/kg/day. In the chronic dietary exposure analysis, the most highly exposed population 

subgroup is All Infants (<1 year old) which utilizes <1% of the cRfD. The general U.S. 

population utilizes <1% of the cRfD. Therefore, dietary exposure to furfural residues in drinking 

water does not pose a risk of concern to the Agency. 

C. Occupational Exposure 

 Handler Exposure and Risk. For all handler exposure scenarios, which include mixers, 

loaders, and applicators, dermal risks are not of concern, provided that handlers use baseline 

personal protective equipment (long-sleeved shirt, long pants, shoes, and socks) and gloves are 

worn; dermal MOEs range from 100 to 1,200. Inhalation risk was identified for applicators that 

apply furfural to large acreages (80 acres was assessed) with an open cab groundboom and for 

mixer/loader exposures during groundboom application or chemigation, resulting in MOEs from 

22 to 46. However, with the addition of a respirator (with an organic-vapor-removing cartridge 
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or other respirator with a canister approved for pesticides); inhalation MOEs range from 220 to 

360. 

 The registrant indicated that applications made to sod farms will likely be less than 80 

acres per application, given the limitation of the additional irrigation water needed after a 

furfural treatment. Furthermore, that sod farms will likely not treat more than 20 acres per day, 

which would translate to MOEs of 144 based on the addition of gloves with baseline personal 

protective equipment (PPE). Therefore, provided that the directions for use on the proposed 

label stating that furfural applications totaling no greater than 18 acres can be made per 24-hour 

period, then no respirator is needed. If the registrant chooses to retain use to include directions 

for applications using groundboom equipment made to more than 18 acres per day, the applicator 

must wear an appropriate organic-vapor-removing respirator. With these mitigation reflected on 

the label, occupational handler exposures do not pose a risk of concern to the Agency. 

 Applications made to golf course greens and tees, which do not fall under the Worker 

Protection Standard purview, can also be sources of dermal and/or inhalation exposures. 

However, applications made to turf on golf courses will be significantly smaller treatment areas, 

where a treated area is no greater than one acre, presuming a contiguous green and tee. For 

example, if one acre is treated using an open cab groundboom, the resulting inhalation MOE for 

applicators is 2,880 without a respirator. 

Postapplication Occupational Inhalation Exposure and Risk. The occupational 

postapplication inhalation assessment yielded results that were almost identical to those for 

bystanders. Because the results of the bystander assessment are considered protective of 

occupational postapplication inhalation exposure, bystander buffer zones were used to represent 

occupational buffer zones. Refer to Tables 1 and 2 for the specific MOEs and buffer zones for 

the respective treatment acreages. 

 Even with the available volatility studies that reflect an irrigation event after a furfural 

application, there is still a significant amount of flux that can off-gas from the soil surfaces 

where a person may experience high inhalation exposures. In the inhalation modeling 

assessment, the furfural flux values in the first 8-hour averaging period of the PERFUM run 

captured all of the predicted concentrations that were above the COC. In other words, the 

majority of the furfural emissions decreased after the first eight hours to below levels that would 

pose risks of concern. Therefore, to reduce inhalation exposures to bystanders and workers 

around treated golf course areas, EPA is requiring that a buffer zone commensurate to the 

treatment size be established and in place for a minimum of eight (8) hours. No person under 

any circumstance is permitted to enter the treatment area or the buffer zone before the 8-hour 

duration has passed. 

Postapplication Dermal Exposure and Risk. The results of the occupational 

postapplication dermal exposure and risk assessment for golf course maintenance and sod 

harvesting indicate that the dermal MOEs range from 7,000 to 14,000, which are greater than the 

target MOE of 100 on the day of application, and therefore, are not of concern. These MOEs are 

based on estimated residues that workers can be exposed to, assuming reentry into the treated 

area 12 hours after treatment. Although furfural would trigger a 24-hour REI based on the 
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Toxicity Category II for primary eye irritation study, the DFR study indicates that residues 

decline to levels below detectable limits within 8 hours of application. Therefore, to minimize 

potential dermal exposures and for consistency with the standard WPS restricted entry durations, 

a 12-hour restricted entry interval is appropriate for the sod farm use. For workers that would 

need to conduct early entry activities in the treated area, access is prohibited until after the 8-

hour buffer zone duration has elapsed, provided that the appropriate PPE is worn. 

D. Residential (Bystander) Exposure 

 Bystander inhalation exposure was assessed for individuals living or working nearby 

application sites. Postapplication dermal exposure was assessed for golfers that may use the golf 

course after furfural treatments. When determining the potential for dermal exposure, the 

Agency considers foliar residues, leaf-to-skin residue transfer, and the exposure duration to that 

pesticide. To calculate potential inhalation exposure, air concentrations were estimated using 

modeling estimates from PERFUM and HECs calculated using the reference concentration 

methodologies were then used to calculate the MOEs. 

 Bystander exposure to furfural emissions primarily depends on the following factors - the 

rate of furfural volatilization, the field conditions that may impact its volatility, and the 

dispersion of the emitted furfural relative to the location of the exposed individual. Risk from 

furfural exposures was estimated based on a concentration of concern (COC), where the 

exposure is of concern if the COC is exceeded. The Agency used the PERFUM to evaluate the 

potential inhalation risks, which incorporates actual weather data and residue flux distributions. 

PERFUM establishes a grid of contoured plot lines representing calculated air concentrations at 

each receptor location for each day. With these estimated emission concentrations at, for 

example, the 95th percentile, the Agency can estimate exceedances of the COC based on either: 

1) the buffer zone at which there will not be an exceedance for 95% of the days; or 2) based on 

the whole field distribution, where the 95th percentile maximum field buffer distance is that 

distance below which air concentrations will not exceed COCs along the 95th % of total 

combined buffer zone perimeters. 

Dermal Exposure. Although a specific turf transferable residue (TTR) study was not 

submitted, the Agency used the available dislodgeable foliar residues (DFR) study on 

ornamentals to estimate potential turf residue values, which generally results in residues higher 

than levels seen in a TTR study. Even assuming that individuals can enter treated areas on a golf 

course as early as 12 hours after a furfural application at the highest use rate, the resulting MOE 

is 190,000. Therefore, these dermal exposures are not of concern, including both adults and 

children that may be exposed to furfural residues on treated areas in golf courses. 

Inhalation Exposure. The target MOE of 30 for bystander inhalation exposure is 

achieved at the 75th percentile based on a 0.5 acre treated field, and between the 70th-75th

percentile based on a treated 0.5 or 1 acre field, resulting in approximately between a 15 to 30 

feet buffer zone, respectively. Tables 1 and 2 are summaries of the MOEs relative to the buffer 

zone distance (in meters), the buffer zone distance at which percentage there is no exceedance of 

the COC, and the meteorological region representing the potential flux, based on the maximum 

application rate. 
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Table 1. MOEs at Varied Distances from a 0.5 Acre Treated Field 1

Meteorological Distance 

Region Percentile 

5 m 10 m 20 m 

75 18 41 -- 

Ventura 3pm 90 7 8 11 2

95 6 6 8 

50 -- -- -- 

75 165 -- -- 

90 5 6 9 

Ventura 7am2

95 `3 3 4 

50 -- -- -- 

75 -- -- -- 

90 4 4 6 Ventura 7pm2

95 3 3 3 

50 -- -- -- 

75 28 83 -- 

90 7 7 9 

Bakersfield 

95 5 5 7 

50 -- -- -- 

75 17 41 -- 

90 4 5 7 

Bradenton 

95 3 4 5 

50 -- -- -- 

75 41 165 -- 

90 9 10 13 

Flint 

95 7 7 9 

50 -- -- -- 

75 28 83 -- 

90 7 7 10 

95 5 5 7 

Tallahassee 

99 3 3 4 

50 -- -- -- 

75 41 165 -- 

90 6 7 10 

Yakima 

95 4 4 6 1

 Based on 24-hour average whole field air concentrations estimated from the Georgia 3E flux profile, with an application rate 

of 69.5 lbs ai/A. MOE = bystander HEC (i.e., = 0.33 mg/m3

) / air concentration at given distance. The LOC is MOE < 30. 2

 GA3E flux subplot study was started at 3:00 pm; additional PERFUM runs, using hypothetical morning and evening start 

times, were conducted to evaluate the effects of more stable atmospheric conditions (7:00 AM and 7:00 PM) and warmer air 

temperatures (7:00 PM). 

-- indicates concentration estimate is zero for this percentile at this distance. 

Table 2. MOEs at Varied Distances from an 1 Acre Treated Field 1

Meteorological Distance 

Region Percentile 

5 m 7 m 10 m 

Ventura 3pm2 50 -- -- -- 
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Distance 

70 41 83 165 

75 10 13 18 

90 5 6 6 

95 5 5 5 

50 -- -- -- 

70 -- -- -- 

75 41 83 165 

90 3 4 4 

Ventura 7am2

95 2 2 2 

50 -- -- -- 

70 -- -- -- 

75 -- -- -- 

90 3 3 3 

Ventura 7pm2

95 2 2 2 

50 -- -- -- 

70 165 165 -- 

75 13 15 21 

90 5 5 5 

Bakersfield 

95 3 4 4 

50 -- -- -- 

70 33 55 165 

75 9 11 17 

90 3 3 4 

Bradenton 

95 3 3 3 

50 -- -- -- 

70 83 165 -- 

75 21 24 41 

90 7 7 7 

Flint 

95 5 5 5 

50 -- -- -- 

70 41 55 165 

75 14 18 28 

90 5 5 5 

Tallahassee 

95 3 4 4 

50 -- -- -- 

70 83 165 -- 

75 18 24 41 

90 4 4 5 

Yakima 

95 3 3 3 1

 Based on 24-hour average whole field air concentrations estimated from the Georgia 3E flux profile, with an application rate 

of 69.5 lbs ai/A. MOE = bystander HEC (i.e., = 0.33 mg/m3

) / air concentration at given distance. The LOC is MOE < 30. 2

 GA3E flux subplot study was started at 3:00 pm; additional PERFUM runs, using hypothetical morning and evening start 

times, were conducted to evaluate the effects of more stable atmospheric conditions (7:00 AM and 7:00 PM) and warmer air 

temperatures (7:00 PM). 
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-- indicates concentration estimate is zero for this percentile at this distance. 

 Even with the available volatility studies that reflect an irrigation event after a furfural 

application, there is still a significant amount of flux that can off-gas from the soil surfaces 

where a person may experience high inhalation exposures. In the inhalation modeling 

assessment, the furfural flux values in the first 8-hour averaging period of the PERFUM run 

captured all of the predicted concentrations that were above the COC. In other words, the 

majority of the furfural emissions decreased after the first eight hours to below levels that would 

pose risks of concern. Therefore, to reduce inhalation exposures to bystanders and workers 

around treated golf course areas, EPA is requiring that a buffer zone commensurate to the 

treatment size be established and in place for a minimum of eight (8) hours. The buffer zone is a 

distance around the perimeter of the treatment area, measured from the edge of the treatment 

block, where entry into the treated area and its buffer zone is prohibited for the duration that the 

buffer zone is in place. With the establishment of the buffer zone for the eight hour duration, the 

Agency believes that this would allow sufficient time for residues to significantly decline to 

below COCs, and be protective of any risk from potential inhalation and dermal exposures. 

E. Aggregate Exposure 

 Based on the current and proposed furfural applications, there is no common effect 

observed in the toxicity studies selected to assess oral, dermal and inhalation exposure expected 

to co-occur that would warrant conducting an aggregate assessment. Therefore, an aggregate 

risk assessment was not conducted. 

III. ECOLOGICAL EXPOSURE AND RISK 

EPA evaluated the potential ecological fate and risk for exposures to nontarget organisms 

from furfural-treated golf course turf and sod farms. Although the ecological risk assessment 

also reflects applications made to outdoor-grown ornamentals, the registrant has since requested 

to delete this proposed use from the draft label, and thus will not be further considered as part of 

this registration action. The following information is a summary of the ecological exposure and 

risk assessment for the proposed golf course and sod farm uses of furfural. For additional 

information, refer to the Agency’s document Furfural. Environmental Fate and Ecological Risk 

Assessment of Proposed Uses on Turf and Ornamentals, dated April 5, 2010. 

A. Environmental Fate 

 Furfural is a heterocyclic aromatic aldehyde that is expected to be relatively short-lived 

(aerobic soil half-life ≤ 1 day), and highly mobile in the environment due to its very high 

solubility in water and low soil affinity. Biotic processes and volatilization are expected to be 

the major routes of dissipation. Furfural has a relatively high vapor pressure and moderately 

high Henry’s Law constant, which indicate that there is a high potential of volatility; however, 

furfural’s volatility from a water surface is reduced when diluted with water. With the high 

potential for solubility in water, furfural is expected to reach surface water through runoff and/or 

spray drift. The Agency will require new aerobic and anaerobic metabolism studies, since the 

submitted studies provided limited information to describe the fate of furfural and, more 

importantly, of its degradates in the environment. 
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Persistence and Transformation. Furfural is stable in hydrolysis, but biodegrades 

in both, aerobic and anaerobic environments at observed rates from approximately one hour to 

<3 days, and via aqueous photolysis (half-life of approximately 6.5 days). Furfural is expected 

to have a low bioaccumulation potential with dissipation following the various primary routes of 

degradation in both aerobic and anaerobic environments, and transformation. The two major 

degradates are furfuryl alcohol, which is presumed to have similar toxicity to furfural per se

because they both contain the furan ring, and 2-furoic acid, which is presumed to have equal to 

or less toxicity than that of the parent. 

In one of the available furfural aerobic soil metabolism studies, conducted on a sandy 

loam soil, 2-furoic acid was the primary degradate detected in the soil extracts, with the highest 

recovery level at 31.9% of the applied amount at 8 through 24 hours post-treatment, and was last 

detected at 30.7% two days after application. Furfuryl alcohol was detected at a maximum level 

of 14.7% at four hours post-treatment and was not detected at any subsequent sampling interval. 

Transport and Mobility. Available batch equilibrium data indicate that furfural 

residues, namely 2-furoic acid, are moderately mobile to mobile in a study using sterilized soils. 

The pH level of the soil may affect the ionization potential of 2-furoic acid, where more acidic 

soils (lower pH) would likely produce higher concentrations of 2-furoic acid, with lower 

mobility; in the ionized form, higher mobility is expected at higher pHs. It appears that 2-furoic 

acid has the potential to contaminate groundwater due to its mobility observed in available 

laboratory and field studies. Another factor that would impact mobility is the high irrigation 

levels typically used on established turf and golf courses. 

 An available laboratory volatility study on furfural indicated that there was rapid 

metabolism of furfural in the viable soils that prevents very substantial volatilization, whereas 

the degree of volatilization was greater in sterile soil. Another volatility study, conducted in the 

field, measured the rate of volatilization, or flux, when furfural was applied in California and 

Georgia soils to bare ground/seeded turf plots, and to established turf plots. All plots were 

irrigated before and after application. In general, the field volatilization study indicated that the 

majority of the flux occurred within the two hours after application, especially in the established 

plots over the bare ground plots. The amount of furfural loss from the fields to the air varied 

widely in California, accounting for approximately between 5 and 55.5% of the applied amount 

in California, and varied to a lesser extent in Georgia accounting for 0.9 to 4.4% of the applied 

furfural. 

Bioaccumulation. Bioaccumulation is not expected for furfural and its degrades since 

the octanol-water partition coefficient is low (KOW <1,000). The KOW values ranged from 1.9 to 

4.4. Since the rate of transformation is rapid in the environment, furfural is not expected to 

biomagnify. 

Atmospheric Effects. Given furfural’s physical and chemical properties and its behavior 

in the environment, ground-level ozone creation is possible in air sheds where furfural is used in 

high volumes. However, given the use pattern and the requirement to irrigate the treated area 

within 15 minutes after application, the Agency believes that furfural emissions are likely to 
12 of 23 

minimally, or not contribute to any process related to stratospheric ozone depletion or global 

warming potential. 

B. Ecological Risk

The Agency’s ecological risk assessment compares toxicity endpoints from ecological 

toxicity data to estimated environmental concentrations (EEC) based on environmental fate 

characteristics, soil and water chemistry, and pesticide use data. To evaluate the potential risks 

to nontarget organisms from the use of furfural, the Agency calculates a Risk Quotient (RQ), 

which is the ratio of the EEC to the most sensitive toxicity endpoint values, such as the median 

lethal dose (LD50) or the median lethal concentration (LC50). 

RQ values are compared to the Agency’s levels of concern (LOC), which indicate 

whether a pesticide, when used as labeled, has the potential to cause adverse effects on nontarget 

organisms. When the RQ exceeds the LOC for a particular category, the Agency presumes a 

potential risk of concern to that category. Table 3 describes the Agency’s LOCs and its 

respective risk presumptions. These RQ values may be further refined by characterization of the 

risk in the assessment. Use, toxicity, fate and exposure are considered when characterizing the 

risk, as well as the levels of certainty and uncertainty in the assessment. 

Table 3. Agency’s LOCs and Risk Presumptions 

Agency’s LOCs and Risk 

Presumptions 

LOC 

Terrestrial Animals

LOC 

Aquatic Animals

LOC Plants 

(Terrestrial, Semi-aquatic, 

and Aquatic)

Acute Risk ≥0.5 ≥0.5 ≥1 

Chronic Risk ≥1 ≥1 N/A 

N/A = not applicable 

 The calculated RQs represent a screening-level assessment. Screening-level assessments 

are based on conservative assumptions. For example, in screening-level assessments the 

maximum labeled application rate, the maximum number of applications, and the shortest 

treatment interval between applications are always used. 

Aquatic Animals and Plants

 The highest acute RQ for freshwater fish is 0.12, which is below the acute LOC of 0.5. 

All other assessed exposures were below the Agency’s LOCs, which include the following 

scenarios: chronic RQs for freshwater fish; acute and chronic RQs for freshwater invertebrates; 

acute RQs for estuarine/marine fish; acute RQs for estuarine/marine invertebrates; and, acute risk 

to aquatic plants. Currently, there are no data to assess chronic risk for marine/estuarine fish and 

invertebrates. 

Terrestrial Animals and Plants

Avian Oral (acute and chronic). Based on available acute oral data, acute risks are 

expected to birds from consumption of treated food items in and near treated areas. 

Additionally, no avian inhalation, avian dietary, or avian reproduction studies are available; 
13 of 23 

therefore, the Agency presumes the potential for risk from these routes of exposure in the 

absence of data. The acute risk LOC is exceeded for all assessed bird sizes and food items, with 

the highest acute RQ of 310 for the smallest size bird assessed.

Avian Inhalation Exposure. In addition to the risk to birds from consumption of 

furfural-contaminated food items, the Agency believes that there is a potential for inhalation 

exposure and risk due to the volatility of furfural in the environment. Acute inhalation data was 

not available to quantify potential inhalation exposures to birds, and the Agency believes that 

extrapolation of mammalian data to estimate avian exposures would likely underestimate 

exposures. However, a relative sensitivity ratio can be extrapolated to the inhalation route to 

estimate avian acute inhalation toxicity using available mammalian and avian acute oral toxicity 

data and the mammalian acute inhalation data. The avian inhalation RQ of 0.28 slightly exceeds 

the Agency’s acute LOC based on the upper bound estimated air concentrations from the 

PERFUM model for an application to a 100 acre treated field, adjusting the estimated 

concentrations to correct for the time gap in the air monitoring data, and adjusting for the 

potential for stagnant meteorological conditions based on application timing. 

 Mammalian Oral (acute and chronic). Based on available mammal acute oral data, 

acute risks are expected to occur at all modeled size classes of mammals. The Agency assessed 

chronic exposure risks to mammals using developmental toxicity data. The acute risk LOC is 

exceeded for almost all assessed mammal sizes and food items, with the highest acute RQ of 68 

for the smallest size mammal assessed. For chronic exposures, RQs were exceeded for all size 

classes and food items, with the highest RQ of 723 for the smallest mammal size assessed.

Mammalian Inhalation Exposure. In addition to the risk to mammals from 

consumption of furfural-contaminated food items, there is a potential for inhalation exposure and 

risk due to the volatility of furfural in the environment. Using available measured data from 

available field volatility studies to estimate maximum air concentrations compared to available 

mammalian acute inhalation effects data, estimated RQs (highest of 0.02) were less than the 

Agency’s LOC. However, the Agency believes that use of the PERFUM modeling provide an 

upper-bound estimated air concentration and risks estimates to nontarget animals. Estimated 

concentrations were corrected for the time gap in the air monitoring data, and adjusting for the 

potential for stagnant meteorological conditions based on application timing. Using the EEC at 5 

meters from the edge of the treated area of a 100-acre treated field, this resulted in an estimated 

RQ of 0.12 for inhalation exposure to mammals, which is below the Agency’s acute species 

LOC of 0.5. 

 Plants (monocot and dicot). Terrestrial modeling of the turf application using TerrPlant 

indicates that the RQ of 1.32 slightly exceeds the acute risk LOC for listed dicots in semi-aquatic 

habitats. All other modeled scenarios for monocots and dicots in dry and semi-aquatic areas are 

below the Agency’s LOC. 

 Terrestrial Invertebrates. The Agency does not currently calculate terrestrial 

invertebrate RQs for most assessments. Furfural is considered practically non-toxic to 

honeybees based on available data.
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IV. REGISTRATION DECISION 

 The registrant, AgriGuard, submitted applications proposing the addition of turf and sod 

farm uses for the end-use product Multiguard ® Protect (EPA Reg. No. 75753-1) on October 11, 

2007. The requested application use is for the control of nematodes and certain soil-born fungal 

diseases, including Phythium, Phytophthora, Fusarium, and Rhizoctonia, on golf course tees, 

greens, and practice greens, as well as turf/sod farms. As required by FIFRA, the Agency 

published a Notice of Receipt for these first use applications on October 26, 2009 and received 

no comments during the public comment period. 

A. Human Health Assessment 

 The human health risk assessment concluded that the databases are adequate for dietary, 

occupational, and non-occupational (bystander) exposures to support a conditional registration 

for these proposed uses and application rates for the furfural end-use product Multiguard ® 

Protect, provided that the labeling changes listed below are incorporated onto the label, and the 

receipt of the required studies. Since the application for the registration of these furfural uses 

was received by the Agency, EPA also included additional guideline requirements for toxicity 

testing, for which sufficient time has not elapsed to generate data. To confirm the EPA’s 

assumptions made in the respective risk assessments, the following studies are required as 

conditions of the registration for the proposed furfural uses. The list includes summaries of the 

assumptions made in the absence of data. 

 Human Health Data Requirements

1. Acute and Subchronic Neurotoxicity Studies. In the available developmental 

toxicity study conducted on the rat, dams exhibited clinical signs one hour post dosing 

and during subsequent dialing examinations. In the 28-day dermal toxicity study 

conducted on rabbits, there were indications of potential neurotoxicity, but was not 

considered severe. Without neurotoxicity studies to better characterize the neurotoxicity 

potential of furfural, the Agency applied an additional 10X database uncertainty factor to 

account for this uncertainty. To confirm that the adequacy of the uncertainty factor and 

to characterize the effects seen in the two studies, EPA is requiring these neurotoxicity 

studies. 

2. Multigeneration Reproduction Study. Part of the revised CFR Part 158 guidelines 

includes the submission of a two-generation reproduction rat study. There was no 

quantitative or qualitative susceptibility seen in either the rat or rabbit developmental oral 

studies. However, there is no multigeneration reproductive toxicity study available to 

evaluate the potential for postnatal toxicity from furfural exposure; therefore, the Agency 

applied an additional 10X database uncertainty factor to account for this uncertainty. To 

confirm that there is no potential for postnatal toxicity from furfural exposure, EPA is 

requiring a multigeneration reproduction study. 

3. Immunotoxicity Study. The toxicological database for furfural for the major routes 

of concern, namely oral and inhalation, is limited. However, the most sensitive toxicity 
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endpoints have been identified for the current dietary and inhalation risk assessments. As 

part of the revised CFR Part 158 data requirements, this study is now required to confirm 

that there are no immunotoxicity effects that would be of concern to the Agency. 

4. Metabolism Study. Currently, there are no pharmacokinetic or furfural-specific 

metabolism studies and the metabolic pathway has not been determined. However, 

available open literature studies in humans and animals indicate that furfural is readily 

absorbed and excreted in the urine. The primary degradates, 2-furoic acid and furfuryl 

alcohol, are expected to be of equal or less toxicity than that of the parent. As part of the 

revised CFR Part 158 data requirements and because there is no available information to 

describe the potential impacts from exposure to the metabolites of furfural, this study is 

now required to confirm that exposure to any furfural metabolites would not cause any 

effects of concern to the Agency. 

4. Acute Inhalation Study. The high potential for the volatilization of furfural indicates 

that individuals may be inadvertently exposed through ambient air. Data for other 

volatile chemicals, e.g., fumigants, indicate that acute inhalation exposures to bystanders 

and workers typically present the greatest risk concern. In the case of furfural, the risk 

assessment identifies the potential for inhalation exposures of concern in the bystander 

scenarios, i.e., golf course workers and individuals who play on golf courses, or live 

nearby golf courses. EPA assumes that exposure can occur at any and all times after 

application (i.e., 24 hours/7 days). In the two available repeat-inhalation studies, both 

studies identified a port-of-entry effect of nasal irritation, the most sensitive effect than 

any systemic endpoints via this exposure route. However, the repeat inhalation study 

does not provide information that would show the potential for acute effects, e.g., nasal 

irritation; therefore, in the absence of an acute inhalation study, the Agency presumes that 

nasal irritation could result from a single exposure. In the absence of an acute inhalation 

study, the Agency relied on the available subchronic inhalation toxicity study to calculate 

the HEC. 

 The combination of using this more-conservative endpoint with the highest 

(acute) exposure typically results in higher estimates. The bystander inhalation 

assessments represent upper-bound estimates with the assumption that a treatment area 

(contiguous tee and green) falling between 0.5 to 1 acre. Additionally, the point of 

departure used for the bystander inhalation assessments was based on nasal irritation 

effects seen in the repeat inhalation toxicity study, which is protective of any other 

potential effects, e.g., systemic effects. Finally, furfural rapidly dissipates in the 

environment, as seen in available field volatility studies where flux levels are 

significantly reduced within one hour of application. 

 Irrigation is essential to manage furfural emissions from the soil surface. Even 

with the available volatility studies that reflect an irrigation event after a furfural 

application, there is still a significant amount of flux that can off-gas from the soil 

surfaces where a person may experience high inhalation exposures. To reduce inhalation 

exposures to bystanders and workers around treated golf course areas, EPA is requiring 

that a buffer zone commensurate to the treatment size be established and in place for 
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eight hours. The buffer zone is a distance around the perimeter of the treatment area, 

measured from the edge of the treatment block, where entry into the treated area and its 

buffer zone is prohibited for the duration that the buffer zone is in place. 

 Given the environmental characteristics of furfural, the conservative approach to 

assess potential bystander inhalation exposures, and applying any uncertainty factors to 

address any database deficiencies, the Agency believes that there is sufficient information 

to support a safety finding to proceed registering the proposed uses, provided that the 

mitigation measures are adopted (e.g., buffer zones) and proposed labeling changes are 

incorporated onto the draft label. To confirm the Agency’s assumptions used in assessing 

inhalation exposure, and because inhalation exposure is a primary exposure route of 

concern, an acute inhalation toxicity study as well as additional field volatility studies are 

required as part of the conditions of registration. 

5. Confirmatory Turf Transferrable Residue Study. To confirm the Agency’s 

assumptions made in using the DFR study, a turf transferrable residue study is 

required as one of the conditions for registration of these proposed uses. 

 Buffer Zones

Buffer zones were estimated using the outputs from the PERFUM modeling, based on the 

various percentiles of the whole field distributions, and predicted MOEs for various distances. 

The buffer zones were determined approximately based on an MOE of 20, which was achieved 

around the 75th percentile. EPA used a weight of evidence approach to set the buffers which 

included consideration of the hazard profile of furfural, the conservative assumptions made in the 

risk assessments, the use profile and application of furfural, and comprehensive analysis of 

results from PERFUM modeling. Agency’s goal for risk management was to achieve buffer 

distances where associated risks may occur, and developed buffer zone distances that are scaled 

based on the application block size. It should be noted that the distances in the tables below are 

not model outputs, although as described above the model outputs were used to inform the 

selection of buffer zone distances. With these buffers listed in Table 4, the Agency believes that 

these are representative of potential inhalation exposures and are protective of human health. 

Table 4. Buffer Zones for Furfural Use on Golf Courses (Tees and Greens) and Sod Farms 

Area Treated (acres) 

at Maximum Application Rate of 69.5 lbs ai/A 

Buffer Zone Distance 

in Feet 

0.5 15 

1 30 

5 150 

10 250 

20 360 

40 550 
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B. Ecological Fate and Effects Assessment 

 The ecological fate and effects review concluded that the database is adequate to conduct 

a limited screening-level assessment with the available data. Based on the available ecological 

studies and information on furfural, the Agency determined that the available information are 

sufficient to support a conditional registration for these proposed uses and application rates for 

the furfural end-use product Multiguard ® Protect, provided that the labeling changes are 

incorporated onto the label, and the receipt of the required studies. The following is a summary 

of the assumptions made in the absence of data, as well as the consideration of the proposed 

furfural uses and its known characteristics in the environment. 

 Ecological Data Requirements

1. Nontarget Aquatic Organisms. There are some significant uncertainties in the 

aquatic exposure assessment, given the limited information in available aerobic soil 

metabolism studies, and the amount of furfural that would move below the soil surface 

after an irrigation event. To account for these data deficiencies, conservative 

assumptions were made where possible to estimate potential exposure and risk to 

nontarget aquatic organisms, which were slightly exceeded only for acute exposure to 

freshwater fish and dicots in semi-aquatic environments. The Agency believes that this 

screening-level assessment is reflective of upper-bound estimates, where the actual 

amount of available furfural that could move to waterbodies and other semi-aquatic areas 

will likely be lower. In the absence of certain toxicity data on aquatic organisms, the 

Agency assumes that there are potential exposure risks to nontarget animals, and will 

require additional environmental hazard statements on the label. To reduce the number 

of uncertainties identified in the risk assessment due to limited or no data, and the risk 

assumptions made in conducting the assessments, the following studies will be required 

as part of conditions for registration: fish acute toxicity (rainbow trout and fathead 

minnow), estuarine/marine acute toxicity (shrimp), aquatic invertebrate life cycle 

(estuarine/marine), early life-stage fish (estuarine/marine), and a fish life cycle study 

(freshwater). 

2. Nontarget Terrestrial Animals. There are some uncertainties in the terrestrial oral 

exposure assessments, given the limited amount of information on remaining furfural 

residues after an irrigation event, and environmental factors that would impact flux rates. 

To account for these data deficiencies, conservative assumptions were made where 

possible by assuming exposure at upper-bound EECs, exposures are based on 100 acretreated fields, and that the bird or mammal is in or adjacent to the treated area 

commensurate with the furfural application rate. 

These assumptions likely overestimate exposure, where models do not consider 

the actual habitat requirements of any particular terrestrial species, but assumed that the 

animals occupy, exclusively and permanently, the treatment area being assessed. The 

assumptions made in the ecological assessment conservatively addressed different routes 

of exposure that can be affected by varying environmental conditions. Factors include 

the significance of the additional irrigation after a furfural application, the timing of 
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application, and the rapid dissipation of furfural in the environment, all of which can 

significantly reduce the amount of residues remaining on the surface of food items. In 

order to be efficacious, the treated area must be irrigated soon after application (product 

label says to irrigate the treated area within 15 minutes of application) in order for the 

furfural to move into the root zone of the soil and come into contact with the target pests, 

i.e., nematodes. This movement of furfural into the soil zone reduces the availability of 

furfural residues on the surface of food items that could otherwise be available to 

foraging animals. EPA is proposing to require a terrestrial field dissipation study to 

measure the washoff from the grass to address this uncertainty. Therefore, the Agency 

believes that there is a lower likelihood of significant furfural residues remaining on 

treated areas that could adversely affect nontarget terrestrial animals. To refine the 

screening-level assessment and confirm the assumptions made in the ecological 

assessment, the Agency is requiring the following studies: avian acute inhalation, avian 

acute oral toxicity (passerine/songbird species), avian subacute dietary toxicity, avian 

reproduction toxicity study, and a mammalian reproduction toxicity study. 

C. Required Labeling Changes 

 Based on the Agency’s findings and proposed mitigation measured needed to be 

protective of human health and exposures to nontarget organisms, the following changes must be 

made to the proposed draft label, as listed below. The most recent stamped and approved label 

(EPA Reg. No. 75753-1), dated December 5, 2007, is accessible online through the Pesticide 

Product Label System at http://oaspub.epa.gov/pestlabl/ppls.home. 

1. This pesticide is subject to the soil Fumigant Management Plans, Good Agricultural 

Practices requirements, and placard/posting requirements, as determined by the 

Agency, to be consistent with the mitigation measures outlined for the soil fumigants. 

Refer to the Agency’s webpage on the Implementation of Risk Mitigation Measures 

for Soil Fumigant Pesticides: 

http://www.epa.gov/opp00001/reregistration/soil_fumigants/. 

2. For the proposed sod farm use, add labeling statements that prohibit entry by any 

person (including workers and bystanders) into the treated area and its buffer zone for 

a minimum duration of eight (8) hours after application for both occupational (subject 

to the WPS) and nonoccupational uses (e.g., golf courses). 

3. For the proposed sod farm use, add labeling statements for groundboom applications 

made to areas totaling 18 acres or greater in the same 24-hour period, all handlers 

(including mixers, loaders, and applicators) must wear a respirator with an organicvapor-removing cartridge with a prefilter approved for pesticides (MSHA/NIOSH 

approval prefix TC-23C), or a respirator with a canister approved for pesticides 

(MSHA/NIOSH approval prefix TC-14G). 

4. Add labeling statements in the Directions for Use sections, as well as in the general 

use directions throughout the label for each use site: “The fumigant-like properties of 
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this pesticide can pose severe risks from inhalation exposure if present in the 

treatment area or buffer zone during and after an application.” 

5. Add labeling statements to require irrigation after application. 

6. Add labeling statements to require buffer zones commensurate to the treatment area, 

as listed in Table 4 above. 

7. Reinstate all labeling statements, including placards, posting, and notification 

language from the most recent Agency-stamped and approved label for the currentlyregistered greenhouse ornamental use. 

8. The Environmental Hazard statement in the draft label must be amended to read as 

follows: 

“This pesticide is toxic to birds. Do not apply directly to water, or to areas 

where surface water is present or to intertidal areas below the mean high water mark. 

Do not apply when weather conditions favor drift from treated areas. Drift and runoff 

from treated areas may be hazardous to aquatic organisms in water adjacent to treated 

areas. Do not contaminate water when disposing of equipment washwaters or rinsate. 

Furfural has certain properties and characteristics associated with chemicals 

detected in groundwater. Furfural residues may leach into ground water if used in 

areas where soils are permeable, particularly where the water table is shallow. 

Furfural may also impact surface water quality due to runoff of rain water. This is 

especially true for poorly draining soils and soils with shallow ground water. This 

chemical is classified as having high potential for reaching surface water via runoff 

several days after application. Leaching and run off of these chemicals will be 

reduced by avoiding applications when heavy rainfall is forecasted to occur within 48 

hours.” 

8. The following language must be added in the Directions for Use section: 

“Air Stagnation and Temperature Inversions

Prior to application, the National Weather Service weather forecast for the day of the 

application and the 8-hour period following the application must be checked to 

determine if unfavorable weather conditions exist or are predicted (see Identifying 

Unfavorable Weather Conditions section) and whether application should proceed. 

Do not apply if an air stagnation advisory is in effect. 

Do not apply if there are light wind conditions observed (under 2 mph) or if the wind 

speed is forecast to remain below 5 mph during the application. 

Do not apply if still or stagnant wind conditions are forecast to persist for more than 
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18 consecutive hours after the start of the application. 

Detailed local forecasts for weather conditions, wind speed, and air stagnation 

advisories may be obtained on-line at: http://www.nws.noaa.gov, on weather radio, or 

by contacting your local National Weather Service Forecasting Office. 

Identifying Unfavorable Weather Conditions

Unfavorable weather conditions block upward movement of air, which results in 

trapping vapors near the ground. The resulting air mass can move off-site in 

unpredictable directions. These conditions typically exist prior to sunset and continue 

past sunrise and persist as late as noontime. Unfavorable conditions are common on 

nights with limited cloud cover and light to no wind and their presence can be 

indicated by ground fog or smog and can also be identified by smoke from a ground 

source that flattens out below a ceiling layer and moves laterally in a concentrated 

cloud. Measurement of wind speed can be determined by taking measurements every 

minute for a ten-minute period. The wind speed is the average of the one-minute 

measurements over this ten-minute period.” 

D. Rationale to Not Impose a Restricted Use Pesticide Classification

Currently registered soil fumigants have been classified as Restricted Use Pesticides 

(RUP) based on their toxicity profiles, which meet specific triggers that warrant this 

classification. Additionally, the complex nature in typical fumigation applications is such that 

requires significant training and expertise by certified applicators better ensures that these 

fumigants are properly and safely applied. The majority of soil fumigants requires specialized 

application equipment that injects the fumigant into the soil, or other means of moving the 

chemical below the soils surface, then followed by a sealing of the soil either by compacting the 

soil layer, tarping the treated area, or applying sufficient water to create a water seal. 

While furfural is fumigant-like in many respects, unlike typical fumigants, furfural is 

applied in a dilute aqueous solution. Additionally, furfural can be applied using conventional 

ground sprayer and hand-held sprayer application equipment and methods. On the basis that 

furfural applications can be made following conventional management practices, the regulatory 

point of departure is based on the most sensitive endpoint, and the overall lower toxicity profile 

of furfural relative to some of the soil fumigants, the Agency believes that it is not appropriate to 

impose a RUP classification for furfural at this time. 

E. Benefits 

 The registrant, AgriGuard, submitted documentation stating that the proposed furfural 

uses would meet the criteria in determining that registration of these uses is in the public’s 

interest. Furfural was originally proposed to be an alternative chemical to methyl bromide, and a 

potential alternative to certain telone uses in golf courses. EPA does not believe this is a direct 

alternative to methyl bromide, the Agency believes that the proposed uses of furfural meet a 

unique use niche for which there are few alternatives. 
21 of 23 

Although, furfural does not appear to target the broad spectrum of pests as does methyl 

bromide and other soil fumigants, furfural would serve as one of two existing pesticides (telone, 

also known as Curfew®, being the other) registered for use on established turf to kill plant 

parasitic nematodes. One of the major benefits of furfural is the lower phytotoxicity potential in 

turf applications, reducing or possibly eliminating the temporary turf damage from telone, or 

requiring a complete turf renovation of the affected area. Specific to the golf course use, EPA 

believes that even with the 8-hour duration that buffer zones must be in place, golf course 

managers are still afforded the flexibility to apply furfural safely while avoiding the need to 

prohibit access to the golf course beyond operational hours. Furthermore, there are some 

geological/ geographical restrictions where telone cannot be applied, i.e., Karst-type soils. 

Finally, the proposed furfural applications can be made using standard ground application 

equipment, versus the specialized equipment required for telone applications (i.e., soil injected 

and rolled over the surface to create a crust seal to contain the gas). 

F. Section 3(c)(7)(B) Finding

Section 3(c)(7)(B) of FIFRA authorizes the Agency to issue a conditional registration for 

the proposed additional uses in the absence of certain required data or data that may be 

insufficient to grant an unconditional registration, if the Agency determines the following: 1) the 

applicant has submitted satisfactory data to support the proposed uses; and, 2) that the proposed 

uses would not significantly increase the risk of any unreasonable adverse effect on the 

environment. 

 In reference to the first determination above, the Agency believes that while certain Part 

158 data has not been submitted, the applicant has submitted satisfactory data to support the 

proposed uses. For the Part 158 data that has not been submitted, insufficient time has elapsed 

for the generation of the data since those data requirements were imposed. The Agency proposes 

to require these data as part of the conditions of registration. This determination is based on the 

fact that the applications for registration were received for approximately three months prior to 

the effective date (December 2007) of the new data requirements. For the other data 

requirements, the Agency is requiring the submission of these studies to confirm the assumptions 

and address any database uncertainty factors applied in the respective risk assessments. Even 

with these outstanding data requirements, EPA believes that there is sufficient available 

information to support the conditional registration of these proposed uses, and that the most 

sensitive endpoints have been identified for human exposure and are likely protective of 

systemic effects. 

In reference to the second determination above, the Agency does not believe that the use 

of furfural during the period of conditional registration will significantly increase the risk of any 

unreasonable adverse human health or ecological effects. This determination is based on the 

finding in the Agency’s conservative human health risk assessment that dietary, occupational, 

and bystander exposure to furfural would not exceed the Agency’s level of risk concern, and 

thereby, cause unreasonable adverse human health effects. The combination of using this moreconservative endpoint with the highest (acute) exposure typically results in very conservative 

estimates. The bystander inhalation assessments represent upper-bound estimates, higher than 
22 of 23 

those that could occur in typical scenarios. Additionally, the point of departure used for the 

bystander inhalation assessments was based on nasal irritation effects seen in the study, which is 

protective of any other potential effects, e.g., systemic effects. Finally, the implementation of the 

buffer zones for at least an 8-hour duration would be sufficient to ensure that the furfural flux 

rates have dropped to below the COCs, and subsequently, below the Agency’s LOC. 

The ecological risk assessment indicated that there is potential for avian and mammalian 

oral exposure risks from furfural residues on food items. As indicated above, however, the 

highly conservative ecological assessment assumes exposure at upper-bound EECs and that the 

bird or mammal is solely feeding in or adjacent to the treated area. If nontarget animals were to 

be exposed to furfural via dietary exposure, the actual residues on or in the food items are 

expected to be significantly lower, given the characteristics of furfural biodegradation and 

volatilization in the environment. Also, as noted above, the very slight exceedances for 

freshwater fish acute RQs are not of regulatory concern based on the current screening-level 

assessment. 

G. Agency’s Proposed Decision 

The Agency believes that with the revised labeling as described above, 1) the applicant 

has submitted satisfactory data to support use of furfural on golf course greens, tees, practice 

greens, and turf/sod farms and, 2) that the proposed uses would not significantly increase the risk 

of any unreasonable adverse effect on the environment. Therefore, the Agency proposes to grant 

this conditional registration, provided that the labeling changes are incorporated onto the label. 

The Agency proposes that submission of the following data, of a quality acceptable to the 

Agency and in accordance with a schedule that will be specified in the registration notice, be a 

condition of registration: 

1. Acute and Subchronic Neurotoxicity Studies. 

2. Multigeneration Reproduction Study. 

3. Immunotoxicity Study. 

4. Metabolism Study. 

5. Turf Transferrable Residues Study. 

6. Acute Inhalation Study. 

7. Avian acute inhalation. 

8. Avian acute oral toxicity, conducted on passerine/songbird species. 

9. Avian subacute dietary toxicity. 

10. Avian reproduction. 
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11. Fish acute toxicity – rainbow trout and fathead minnow. 

12. Estuarine/marine acute toxicity – shrimp. 

13. Aquatic invertebrate life cycle (estuarine/marine). 

14. Early life-stage fish (estuarine/marine). 

15. Fish life cycle (freshwater). 

16. Mammal reproduction. In lieu of an ecological-specific study, the Agency will accept 

an acceptable multigeneration reproduction study in order to assess the potential 

mammalian reproductive effects from exposure to furfural. 

17. Terrestrial Field Dissipation Study and Field Volatility Study 

18. Aerobic Soil Metabolism Study 

19. Anaerobic Soil Metabolism Study 

20. Environmental Chemistry Methods and Independent Laboratory Validations for Soil, 

Water, and Air (parent only) for furfural parent and its degradates, 2-furioc acid, and 

furfuryl alcohol