Page 2 of 36

the dietary, drinking water, residential (handler and post-application), and occupational (handler 

and post-application) routes for trifluralin.

The toxicity database for trifluralin is substantially complete. An immunotoxicity study is 

required for registration review under the new data requirements for pesticides (40 CFR § 158). 

Following data evaluation, HED will determine if this study will impact the toxicity endpoints 

for trifluralin. As part of the registration review risk assessment process, the need for the 

required neurotoxicity battery (acute and subchronic neurotoxicity studies) was discussed by the 

Hazard and Science Policy Council (HASPOC) on March 15, 2012. The available data on 

trifluralin and other structurally related dinitroanilines did not indicate a concern for 

neurotoxicity. The HASPOC concluded that based on a weight-of-evidence approach, 

considering all the available hazard and exposure information for trifluralin, the acute and 

subchronic neurotoxicity studies are not needed at this time. The requirement for the 

immunotoxicity study remains outstanding.

Trifluralin exhibits low acute toxicity in rats via the oral, dermal, and inhalation routes of 

exposure. In the rabbit studies, trifluralin has an LD50 value of 5000 mg/kg when applied

dermally (Toxicity Category IV). It is a slight eye irritant, but not a skin irritant; however, it was 

found to be a dermal sensitizer in guinea pigs. The kidney is the principal target organ. 

However, subchronic oral studies in the rat and dog show that the liver is also a target organ with 

increased liver weights and changes in clinical chemistry parameters. The Agency classified 

trifluralin as a Group C- “possible” human carcinogen. The Q1

*

of 5.79 X 10-3(mg/kg/day)-1was 

updated to 2.96 x 10-3(mg/kg/day)-1in 2004 based on the Fischer 344 Rat Dietary 3⁄4’s scaling 

factor (May 11, 2004, TXR No. 0052534). 

Trifluralin is among the group of 58 pesticide active ingredients on the initial list to be screened 

under the Endocrine Disruptor Screening Program (EDSP). Once all required Tier 1 and Tier 2 

data have been received and reviewed, the endpoints and safety factors used for risk assessment 

purposes will be examined and a new risk assessment performed if necessary. For further 

information on the status of the EDSP, the policies and procedures, the list of 67 chemicals, 

future lists, the test guidelines and the Tier 1 screening battery, please visit our website: 

http://www.epa.gov/endo/. 

The existing residue chemistry database for trifluralin is adequate for risk assessment purposes. 

The qualitative nature of the residue in plants and animals has been adequately identified, 

characterized and is understood. No additional data are required at this time; however, there are 

some data that have been submitted by the registrant as a result of data call-in (DCIs) requests 

for trifluralin which were outlined in the most recent residue chemistry chapter (R. Griffin, 

D296627, 03/04/04) that will be reviewed during the registration review process. Additionally, 

the Agency has recently responded to comments received from the registrant regarding the use of 

trifluralin on rapeseed forage; processing studies on mint, grape, and plum; and ruminant 

metabolism and ruminant feeding studies. Based on the reassessed tolerances for alfalfa forage 

and hay, a new dietary burden was determined. Due to the relatively low dietary burden for dairy 

cattle for trifluralin, no tolerances on livestock commodities are needed at this time (S. Piper, 

D399348,02/29/12). 
Page 3 of 36

In the most recent acute, chronic and cancer dietary assessments (08/10/1994) results did not 

exceed HED’s level of concern. New acute, chronic and cancer dietary exposure and risk 

assessments may be required during registration review, which incorporate current consumption 

information, updated residue values and percent crop treated information while directly 

incorporating drinking water values into the assessment. 

The residential exposure database is adequate to support the registration review process for 

trifluralin. In the 2004 risk assessment, all of the non-cancer residential handler and postapplication risk estimates were below the Agency’s level of concern. An updated residential 

exposure assessment may be required under registration review based upon revisions to HED’s 

Residential SOPs. 

The occupational exposure database is inadequate to support the registration review process for 

trifluralin due to lack of Dislodgeable Foliar Residue (DFR) studies. The 1996 RED assessed the 

potential for exposure to mixers, loaders, applicators, or other handlers arising from usage of the 

liquid and granular formulation and concluded that the cancer risk estimates for occupational 

handlers did not exceed 1x10-5(mg/kg/day)-1. Non-cancer occupational handler risk estimates 

were not reported in the RED. Also, the 1996 RED qualitatively assessed the potential postapplication exposure from re-entering treated turf, treated ornamentals, and food/fiber crop sites. 

The RED document suggested that the occupational post-applications risk estimates were below 

the Agency’s level of concern. Based on the 2011 BEAD memo, there are many use sites for 

trifluralin that may have changed since the exposure and risk assessment to support the 1996 

RED. New occupational handler and post-application assessments may be necessary at the time 

of registration review to incorporate the most current registered uses, updated unit exposure data, 

and most current policies and guidelines for assessing occupational exposure and risk estimates. 

Introduction

HED evaluated the most recent human health risk assessment for trifluralin to determine if 

sufficient data are available, and if further updates are needed to support registration review. 

The most recent human health risk assessment was performed in 2004 (R. Griffin, D296628) to 

support the Tolerance Reassessment Decision (TRED) document.

Trifluralin is a selective, pre-emergence, dinitroaniline herbicide registered for the control of 

annual grasses and certain broadleaf weeds. Tolerances for residues of trifluralin (α,α, αtrifluoro-2,6-dinitro-N. N-dipropyl-p-toluidine) in/on plant and processed commodities are 

currently expressed in terms of the residues of trifluralin. Tolerances are established for plant 

commodities under 40 CFR §180.207 and tolerances range from 0.05 ppm to 2.0 ppm. The 

current supported uses for trifluralin are primarily for soybeans and cotton, but it is also 

registered for use on a variety of food and feed crops including: alfalfa, asparagus, barley, 

Brassica vegetables, bulb vegetables, celery, citrus fruits, corn (field), cotton, cucurbit 

vegetables, endive, flax, fruiting vegetables, grapes, hops, legume vegetables, peanuts, 

peppermint, root and tuber vegetables, rapeseed (canola), safflower, sorghum, spearmint, stone 

fruits, sugarcane, sunflower, tree nuts, and wheat. Tolerances for residues of trifluralin in/on

livestock commodities have not been established. The chemical structure and nomenclature of 
Page 4 of 36

trifluralin and its metabolites and the physicochemical properties of technical grade trifluralin are 

presented in Tables 1 and 2.

Hazard Identification/Toxicology

The toxicity database for trifluralin is incomplete under the new 40 CFR Part 158 data 

requirements for conventional pesticides, which require certain generic testing, including an 

immunotoxicity study (see Table 3). Subsequently, the Hazard and Science Policy Council 

(HASPOC) met on March 15, 2012 to discuss data requirements for the neurotoxicity battery 

(acute and subchronic neurotoxicity studies) for the registration review risk assessment. The 

available data on trifluralin and other structurally related dinitroanilines do not indicate a concern 

for neurotoxicity so the HASPOC concluded that these studies are no longer required. The 

requirement for the immunotoxicity study remains outstanding.

As shown in Table 4, technical trifluralin exhibits low acute toxicity in rats via the oral, dermal, 

and inhalation routes of exposure. In the rabbit studies, trifluralin has an LD50 value of 5000 

mg/kg when applied dermally (Toxicity Category IV). It is a slight eye irritant, but not a skin 

irritant; however, it was found to be a dermal sensitizer in guinea pigs. 

The toxicity profile for trifluralin is presented in Table 5. Subchronic oral studies in the rat and 

dog show that the liver is a target organ with increased liver weights and changes in clinical 

chemistry parameters. However, the kidney is the principal target organ. These findings are 

summarized in a peer review of trifluralin (April 11, 1986, TXR No. 0005578) and include the 

following observations: kidney and bladder tumors, decreased kidney weights, increased blood 

urea nitrogen (BUN), increases in total protein, aspartate aminotransferase and lactate 

dehydrogenase in the urine. Also, protein electrophoresis of urine samples showed α1-globulin 

and α2-globulin, tubular hyaline casts in the kidneys, minimal cortical tubular epithelial 

regeneration observed microscopically, and increased incidence of progressive 

glomerulonephritis. The Q1

*

of 5.79 X 10-3(mg/kg/day)-1 was updated to 2.96 x 10-3

(mg/kg/day)-in 2004 based on the Fischer 344 Rat Dietary 3⁄4’s scaling factor (May 11, 2004, 

TXR No. 0052534) and is still based on the incidence of male rat thyroid follicular cell 

combined adenoma, papillary adenoma, cystadenoma, and carcinoma tumors. It has been 

classified as a Group C (“Possible” Human Carcinogen). Extensive testing showed, however, 

that trifluralin is neither mutagenic nor genotoxic, and does not inhibit the polymerization of 

microtubules in mammalian cells. 

Endocrine Disruption Screening Program 

"As required by FIFRA and FFDCA, EPA reviews numerous studies to assess potential adverse 

outcomes from exposure to chemicals. Collectively, these studies include acute, subchronic and 

chronic toxicity, including assessments of carcinogenicity, neurotoxicity, developmental, 

reproductive, and general or systemic toxicity. These studies include endpoints which may be 

susceptible to endocrine influence, including effects on endocrine target organ histopathology, 

organ weights, estrus cyclicity, sexual maturation, fertility, pregnancy rates, reproductive loss, 

and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests and 
Page 5 of 36

chronic studies that assess growth, developmental and reproductive effects in different 

taxonomic groups. As part of the reregistration decision for trifluralin, EPA reviewed these data 

and selected the most sensitive endpoints for relevant risk assessment scenarios from the existing 

hazard database. However, as required by FFDCA section 408(p), trifluralin is subject to the 

endocrine screening part of the Endocrine Disruptor Screening Program (EDSP)."

EPA has developed the EDSP to determine whether certain substances (including pesticide 

active and other ingredients) may have an effect in humans or wildlife similar to an effect 

produced by a “naturally occurring estrogen, or other such endocrine effects as the Administrator 

may designate.” The EDSP employs a two-tiered approach to making the statutorily required 

determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a 

chemical substance to interact with the estrogen, androgen, or thyroid (E, A, or T) hormonal 

systems. Chemicals that go through Tier 1 screening and are found to have the potential to 

interact with E, A, or T hormonal systems will proceed to the next stage of the EDSP where EPA 

will determine which, if any, of the Tier 2 tests are necessary based on the available data. Tier 2 

testing is designed to identify any adverse endocrine related effects caused by the substance, and 

establish a dose-response relationship between the dose and the E, A, or T effect. 

Under FFDCA section 408(p), the Agency must screen all pesticide chemicals. Between October 

2009 and February 2010, EPA issued test orders/data call-ins for the first group of 67 chemicals, 

which contains 58 pesticide active ingredients and 9 inert ingredients. Trifluralin was included 

on that list and has been issued an order to conduct the Tier 1 testing. Once all required Tier 1 

and Tier 2 data have been received and reviewed, the endpoints and safety factors used for risk 

assessment purposes will be examined and a new risk assessment performed if necessary. For 

further information on the status of the EDSP, the policies and procedures, the list of 67 

chemicals, future lists, the test guidelines and the Tier 1 screening battery, please visit our 

website: http://www.epa.gov/endo/. 

Conclusion

The toxicity database for trifluralin is complete except for an immunotoxicity study required 

under the 2007 revised 40CFR Part 158 Toxicology Data Requirements. The endpoints, points of 

departure, and the FQPA Safety Factor for trifluralin will be re-evaluated during registration 

review based on the submission and review of these outstanding data as well as all of the 

currently available data.

Residue Chemistry

The existing residue chemistry database for trifluralin is adequate for risk assessment purposes. 

No additional data are required at this time; however, there are some submitted data received as a 

result of a Data Call-In (DCIs) request for trifluralin which was outlined in the most recent 

residue chemistry chapter (R. Griffin, D296627, 03/04/04) that will be reviewed during the 

registration review process. The qualitative nature of the residues of trifluralin in plants and 

animals has been adequately identified, characterized and is understood. 
Page 6 of 36

The HED Metabolism Assessment Review Committee (MARC) has reviewed the trifluralin

toxicology and metabolism data (03/09/04) and recommends that the tolerance expression for 

plant and livestock should include parent only. The MARC also recommended that for the 

purposes of risk assessment estimates should be based on residue estimates of trifluralin and

metabolites TR-2, TR-4, TR-5, TR-6, TR-7, TR-14, TR-15, TR-42 and TR-44 for livestock 

commodities and parent only for plant commodities. The Agency has determined that tolerances 

for trifluralin residues in eggs and poultry tissue are not required based on the results of the 

respective poultry metabolism and feeding studies (CFR §180.6(a)(3)). 

The Agency has provided responses to comments received from the registrant regarding requests 

for residue data on rapeseed forage; processing studies on mint, grape, and plum; and ruminant 

metabolism and ruminant feeding studies (S. Piper, D399348,02/29/12). Based on the reassessed 

tolerances for alfalfa forage and hay, a new dietary burden is needed. The potential dietary 

exposure of livestock to trifluralin residues was calculated using the recent Agency guidance on 

calculating dietary exposure from “reasonably balanced” livestock diets. To determine the need 

for tolerances for residues trifluralin in milk and tissues, the anticipated secondary residues in 

cattle matrices were estimated using transfer coefficient factors calculated from the maximum 

residues of trifluralin observed at the dose level closest to the reasonable dietary burdens in the 

ruminant metabolism study. Based on the transfer coefficients for livestock tissues and the 

relatively low dietary burden for dairy cattle of 2.6 ppm for trifluralin, no tolerances on livestock 

commodities are needed at this time. 

MARC concluded that the confined rotational crop study is adequate and a plant back interval 

(PBI) of 100 days should be added to the labeling, as this shorter interval would lead to crop 

injury. Therefore, a PBI of 5 months should be added to EPA Reg. No 62719-97 in the directions 

for vegetable gardens, since no PBI appears on the label.

Conclusion

The database for trifluralin is considered adequate for risk assessment. No new residue 

chemistry data requirements have been identified for trifluralin to support registration review; 

however, there are some additional data for trifluralin that will be evaluated during the 

registration review process. 

Dietary Exposure and Risks

A refined (anticipated residues from field trials and percent crop treated) dietary risk assessment 

was completed in 2004 using DEEM-FCIDTM (S. Piper, D296628, 08/10/04). 

Acute

An acute dietary endpoint was only identified for females 13-50 years of age. Estimated acute 

dietary risk for females age 13-50 associated with the use of trifluralin do not exceed the 

Agency’s level of concern. The acute dietary risk estimate for females 13-50 years of age is 

approximately <1% of the acute population adjusted dose (aPAD) at the 99.9th percentile.
Page 7 of 36

Chronic

Chronic dietary risk estimates associated with the use of trifluralin do not exceed the Agency’s 

level of concern for any population subgroup, including the most highly exposed subgroup 

children 1-2 yrs. The chronic dietary risk for all population subgroups is <1% of the chronic 

population adjusted dose (cPAD).

Cancer

Cancer dietary risk estimates for the general U.S. population is 1.64x 10-7 mg/kg/day for 

trifluralin which is below the Agency’s level of concern.

Drinking Water

A Tier II screening level drinking water assessment was conducted to support the tolerance 

reassessment eligibility decision for trifluralin. The recommended estimated drinking water 

concentrations (EDWCs) are based on the use parameters of soybean. The estimates of 7.0 ppb 

for acute exposure, 0.4 ppb for chronic (cPAD) exposure, and 0.3 ppb for carcinogenic risk 

estimates. 

Conclusions

The dietary exposure database is adequate to support the existing registration. However, it may 

be necessary for HED to conduct a new dietary exposure assessment for trifluralin including new 

and updated information and policies, which may include directly incorporating drinking water 

estimates into the dietary assessment. The revised assessment should include updated 

consumption information, any changes in the toxicology endpoints, and utilize the latest version 

of DEEM-FCID. 

Residential Exposure

Trifluralin is registered for a variety of non-occupational use sites. Based on the BEAD 

Chemical Profile for Registration Memo (December 1, 2011), of the use sites for which 

trifluralin is labeled, the following may result in residential exposure: ornamental lawns and turf, 

golf course turf, ornamental herbaceous and woody, turf farms, conservation reserve areas, fence 

rows, rights-of-way, pathways, pre-paved areas, landscape plantings, septic drain fields, 

sidewalks, and tennis courts. The last Residential Exposure Assessment was completed in 2004 

to support the Tolerance Reassessment Evaluation Decision (TRED) Document for Trifluralin 

(D296625, S. Recore, 5/6/2004). 

Residential Handlers

The 2004 Residential Exposure Assessment (D296625, S. Recore, 5/6/2004) assessed the 

following residential exposure scenarios:

o loading/applying granulars with a belly grinder, granulars with a push-type 

spreader, granulars using a spoon, measuring scoop, shaker can, or via hand;
Page 8 of 36

o mixing/loading/applying liquids with a hose-end sprayer, liquids with low 

pressure handwand sprayer, liquids with backpack sprayer; and 

o applying trifluralin impregnated fabric squares to soil.

The exposure scenarios included the maximum application rates for both the non-cancer and 

cancer assessments, with the exception of one use. The assessment used 3 lbs ai/acre as the 

typical rate for the cancer ornamentals assessment. The assessment assumed adult handlers 

weighted 70 kg and represent a handler wearing typical residential clothing attire of shortsleeved shirt, short pants, socks, shoes, and no gloves. The amounts handled or treated were 

based on the 2001 Standard Operating Procedure 12: Recommended Revisions to the Standard 

Operating Procedures for Residential Exposure Assessment. The unit exposures were based on 

data from the Pesticide Handlers Exposure Database (PHED) Version 1.1, two ORETF Handler 

studies: Homeowner Push-Type Spreader (OMA003); Homeowner Hose-end and Hand-held 

Sprayer; and a proprietary study: Worker Exposure Study During Application of Regent 20GR 

In Banana Plantation, EPA MRID 452507-02 (Fipronil Study).

For residential handlers, the calculations of short-term inhalation non-cancer risk indicate that 

the MOEs are greater than 100 for all residential handler scenarios (MOE range 61,000 to 

70,000,000). The calculations of residential handler cancer risk indicate that all scenarios have a 

cancer risk estimate of less than 1x10-6.

Residential Post Application 

The 2004 Residential Exposure Assessment (D296625, S. Recore, 5/6/2004) addressed the 

following post-application exposure scenarios:

o dermal exposure from residue on lawns (adult and toddler), on golf course turf grass 

(adult and youth); on home gardens (adult and youth); 

o hand-to-mouth transfer of residue on lawns (toddler); 

o object-to-mouth transfer of residues on lawns (toddler); 

o incidental ingestion of soil from pesticide treated residential areas (toddler); and 

o incidental ingestion of granules from pesticide-treated residential areas (toddler) 

The exposure scenarios include the TTR value from a trifluralin-specific turf transferable residue 

study (MRID 457456-01). The assessment assumed non-cancer residential risks for both adults 

and children were based generally on maximum application rates and parameters specified in the 

2001 Standard Operating Procedure 12: Recommended Revisions to the Standard Operating 

Procedures for Residential Exposure Assessment. The transfer coefficients were utilized from 

SOPs for residential exposure, draft SOPs for golfer exposure assessment, and the Agricultural 

Default Transfer Coefficient SOP. The cancer risk estimates were based on the assumption that 

adults may be exposed on day of application following both the permitted applications each year. 

Exposure durations, length, and frequency were assumed to be worst case. 
Page 9 of 36

The risk estimates indicated that the MOEs are greater than 100 for all post-application scenarios 

(MOEs range: 110,000 to 680,000,000). The calculations of residential post-application cancer 

risk indicate that all scenarios have a cancer risk estimate of less than 1x10-6.

Conclusions

Currently registered residential uses appear to be similar to those previously assessed; however, 

the Standard Operating Procedures and related parameters for performing residential exposure 

and risk assessments have changed since the 2004 assessment. Revised residential handler and 

post-application assessments may be needed to incorporate the changes to the Standard 

Operating Procedures of Residential Pesticide Exposure Assessment (February 2012 or most 

current version), body weight parameter changes, and any toxicological information that may be 

updated at the time of registration review. 

Spray Drift/Bystander Exposure Estimates

Residential bystander inhalation exposures resulting from off-site transport (e.g., spray drift or 

volatilization) may occur as a result of applications of trifluralin. The Agency is in the process of 

evaluating these types of exposures and may, as appropriate, develop policies and procedures to 

identify the need for and, subsequently, the way to incorporate post-application inhalation 

exposure into the Agency's risk assessments. The need for a bystander inhalation risk 

assessment for trifluralin should be examined during registration review.

Aggregate Risk Assessment

The 2004 Residential Exposure Assessment (D296625, S. Recore, 5/6/2004) assessed the 

combined cancer risk values for residential handler and residential post-application exposures 

associated with turf applications. The combined handler plus post-application cancer risk 

associated with applications to residential turf grass is 5.4 x10-7. A new aggregate risk 

assessment may be needed at the time of registration review to incorporate the most current 

dietary and drinking water uses with the updated residential exposure and risk estimates. 

Conclusion

Updated aggregate exposure and risk assessments may be required under registration review 

based on the need for directly incorporating drinking water into the dietary exposure estimates. 

Revised aggregate exposure and risk assessment may also be needed if toxicological endpoints 

change or other new data are received by the Agency which impact exposure estimates.

Occupational Exposure

Based on the BEAD Chemical Profile for Registration memorandum (December 1, 2011), of the 

use sites for which trifluralin is labeled, many may result in occupational exposure. These use 

sites include but are not limited to the following: a variety of agricultural vegetable, fruit, grain 

and fiber use sites, ornamental lawns and turf, golf course turf, ornamental herbaceous and 

woody, turf farms, conservation reserve areas, fence rows, rights-of-way, pathways, pre-paved 

areas, landscape plantings, septic drain fields, sidewalks, and tennis courts. Application methods 
Page 10 of 36

include chemigation, and aerial as well as ground applications (banded, broadcast, spot, 

broadcast and hand-held granular, and soil incorporated). The last occupational exposure and 

risk assessment was completed as part of the 1996 Registration Eligibility Document (RED). 

Occupational Handlers

The 1996 RED assessed the potential for exposure to mixers, loaders, applicators, or other 

handlers arising from usage of the liquid and granular formulations. The applications varied and 

include aerial, groundboom, granular spreader, as well as push-type and handheld equipment. 

The last assessment assumed that handlers donned baseline clothing except for the granular row 

planter scenario and the mixer/loaders of liquid formulations. Additional PPE such as coveralls 

and chemical-resistant gloves were assessed. The row-planter handlers were also assumed to 

have enclosed cabs. Based on use patterns and PPE assumptions, the 1996 RED concluded that 

the cancer risk estimates for occupational handlers did not exceed 1x10-5(mg/kg/day)-1. Noncancer occupational handler risk estimates were not reported in the 1996 RED.

Based on the 2011 BEAD memo, use sites for trifluralin may have changed since the exposure 

and risk assessment to support the 1996 RED. The most current use sites should be assessed as 

part of registration review. Additionally, recommended unit exposures for occupational handler 

assessments have generally been derived only from PHED. However, recently both the ORETF 

and AHETF have produced pesticide handler exposure monitoring data that the Agency is using 

in place of PHED (http://www.epa.gov/pesticides/science/handler-exposure-data.html). As more 

reliable data become available (such as that from the AHETF and ORETF), the Agency will 

continue to replace existing data. HED will incorporate new exposure monitoring data, as 

necessary, during Registration Review. A new occupational handler assessment may be 

necessary at the time of registration review to incorporate the most current registered uses, 

updated unit exposure data, and will reflect the most current policies and guidelines for assessing 

occupational exposure and risk estimates. 

Occupational Post Application

The 1996 RED qualitatively assessed the potential post-application exposure from re-entering 

treated turf, treated ornamentals, and food/fiber crop sites. The 1996 RED document suggested 

that the occupational post-applications would be no higher than the exposure to the occupational 

handlers. Therefore, the Agency did not anticipate that the exposure and risk estimates for the 

post-application scenarios would exceed 1x10-5(mg/kg/day)-1.

Based on the 2011 BEAD memo, use sites may have changed since the 1996 RED document. 

The most current use sites should be assessed as part of reregistration review. Additionally, 

HED has recently updated the Agricultural Transfer Coefficient Policy 3 document to reflect the 

adoption of all Agricultural Reentry Exposure Task Force (ARTF) data. These data were 

reviewed in 2008 by the FIFRA SAP. As more reliable data become available the Agency will 

continue to replace existing data. A new occupational post-application assessment may be 

necessary at the time of registration review to incorporate the most current registered uses, 

updated transfer coefficient data, and reflect the most current policies and guidelines for 

assessing occupational exposure and risk estimates. 
Page 11 of 36

Conclusions

The occupational exposure database is inadequate to support the registration review process for 

trifluralin due to lack of Dislodgeable Foliar Residue (DFR) studies. In accordance with the 

updated Part 158 data requirements (2007), one or more DFR studies are required when a 

pesticide has residential or occupational uses that could result in post-application dermal 

exposure. Since trifluralin is registered for use at these sites, these studies are required. Updated 

occupational handler exposure assessments may be required under registration review based 

upon revisions to the Agency’s scenario-specific surrogate handler exposure data 

(http://www.epa.gov/pesticides/science/handler-exposure-table.pdf). An occupational postapplication assessment will also be required under registration review to incorporate revisions to 

the transfer coefficient policy (http://www.epa.gov/pesticides/science/exposac_policy3.pdf) and 

inclusion of DFR studies submitted to support registration review for trifluralin. Additionally,

revised assessments may be needed to incorporate the changes to body weight parameter changes 

and any toxicological information that may be updated at the time of registration review. 

Human Studies

Previous assessments relied in part on data from studies in which adult human subjects were 

intentionally exposed to a pesticide or other chemical. These data, which include studies from 

the Pesticide Handlers Exposure Database Version 1.1 (PHED 1.1), are subject to ethics review 

pursuant to 40 CFR 26, have received that review, and are compliant with applicable ethics 

requirements. Future assessments will rely on the most current and updated data from a variety 

of sources. All future data used are subject to ethics review pursuant to 40 CFR 26. 

Descriptions of data sources as well as guidance on their use can be found at 

http://www.epa.gov/pesticides/science/handler-exposure-data.html and

http://www.epa.gov/pesticides/science/post-app-exposure-data.html.

Public Health and Pesticide Epidemiology Data

An updated review of trifluralin incident report was recently prepared by HED (S. Recore, 

D397847, 03/14/2012). For this evaluation, the OPP Incident Data System (IDS) 

indicated moderately high frequency of incidents involving trifluralin. Although most of these 

incidents were of low severity, it appears exposures to trifluralin have the potential to result in 

high severity outcomes. Consequently, based on the frequency of exposures and the potential for 

exposures to result in high severity outcomes, these incident data may warrant further analysis in 

the preliminary risk assessment phase of Registration Review.

With respect to the epidemiological research from the Agricultural Health Study, there are two 

notable preliminary reports from the Agricultural Health Study (AHS) relating to colon cancer 

and to myocardial infarction. The Agency will continue to monitor AHS research reports with

respect to trifluralin. If a concern is triggered, additional analysis will be included in the risk 

assessment. Follow-up studies from the AHS and other sources will be evaluated (if available) at 

the time of the risk assessment.
Page 12 of 36

Tolerance Assessment and International Harmonization

Tolerances are established under 40 CFR §180.207 for residues of the herbicide and plant growth 

regulator trifluralin in or on a variety of food and feed crops (see Table 7). These tolerances are 

based on the residue analysis of trifluralin. There are currently no established or proposed Codex, 

Canadian, or Mexican maximum residue limits (MRLs) for trifluralin. 

“Tolerances are established under 40 CFR §180.207 for residues of the herbicide and plant 

growth regulator trifluralin, including its metabolites and degradates, in or on the commodities in 

Table 7. Compliance with the tolerance levels specified is to be determined by measuring only 

trifluralin (α, α, α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine), in or on the commodity.”

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.epa.gov/compliance/resources/policies/ej/exec_order_12898.pdf. The Office of Pesticide 

Programs (OPP) typically considers the highest potential exposures from the legal use of a 

pesticide when conducting human health risk assessments, including, but not limited to, people 

who obtain drinking water from sources near agricultural areas, the variability of diets within the 

U.S., and people who may be exposed when harvesting crops. Should these high exposures 

indicate potential risks of concern, OPP will further refine the risk assessments to ensure that the 

risk estimates are based on the best available information.

Cumulative Risk Assessment

At this time, EPA does not have available data to determine whether trifluralin has a common 

mechanism of toxicity with other substances. EPA has not made a common mechanism of 

toxicity finding as to trifluralin or any other substances, and trifluralin does not appear to 

produce a toxic metabolite produced by other substances, which have tolerances in the U.S. 

Therefore, EPA has not assumed that trifluralin has a common mechanism of toxicity with other 

substances.

Data Requirements

HED does not anticipate that additional residue chemistry, toxicology, or occupational/ 

residential exposure data will be required for the registration review process of trifluralin with 

the exception of the following studies listed below:

Immunotoxicity Study (OPPTS guideline 870.7800)

Dislodgeable Foliar Residue Studies (OPPTS guideline 875.2100)
Page 13 of 36

Data Call-In

The registrant submitted studies in response to a data call-in) requests for trifluralin which were 

outlined in the most recent residue chemistry chapter (R. Griffin, D296627, 03/04/04) that will 

be reviewed during the registration review process. These studies include a magnitude of residue 

studies on asparagus, carrots, grapes and wheat (D240693), alfalfa (D231299), cotton gin byproduct (D240093), and an analytical method (D273840). 

 
Page 14 of 36

Table 1. Trifluralin Nomenclature

Chemical structure

Common name Trifluralin

Molecular Formula C13H16F3N3O4

Molecular Weight 335.3

IUPAC name α,α,α-trifluroro-2,6-dinitro-N,N-dipropyl-p-toluidine

CAS name 2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl)benzenamine

CAS # 1582-09-8

PC Code 036101

Table 2. Physicochemical Properties of Trifluralin

Parameter Value Reference

Melting point/range 42-49 C Trifluralin Update dated 10/29/91

pH 5.9 ± 0.1 saturated aqueous solution D207577, 4/9/97, K. Dockter

Density or specific gravity (22 C) 1.36 g/mL D207577, 4/9/97, K. Dockter

Water solubility (25 C) <1 ppm D207577, 4/9/97, K. Dockter

Solvent solubility (25 C) readily soluble in organic solvents such 

as acetone, acetonitrile, chloroform, 

dichloromethane, ethyl acetate, and 

toluene at >100 g/100 mL, and in 

hexane at 5-6.7 g/100 mL or 

methanol at 3.3-4 g/100 mL

D207577, 4/9/97, K. Dockter

Vapor pressure (25 C) 6.1 x 10-3

Pa D207577, 4/9/97, K. Dockter

Dissociation constant (pKa) not required; does not dissociate D207577, 4/9/97, K. Dockter

Octanol/water partition coefficient 

(log Kow; 20 C)

4.83 D207577, 4/9/97, K. Dockter

UV/vis absorption spectrum not available
Page 15 of 36

Table 3: Toxicology Data Requirements for Trifluralin

Test Technical

Required Satisfied

870.1100 Acute Oral Toxicity......................................................

870.1200 Acute Dermal Toxicity .................................................

870.1300 Acute Inhalation Toxicity.............................................

870.2400 Primary Eye Irritation...................................................

870.2500 Primary Dermal Irritation .............................................

870.2600 Dermal Sensitization ....................................................

yes

yes

yes

yes

yes

yes

yes

yes

yes

yes

yes

yes

870.3100 Oral Subchronic (rodent)..............................................

870.3150 Oral Subchronic (nonrodent)........................................

870.3200 21/28-Day Dermal........................................................

870.3250 90-Day Dermal .............................................................

870.3465 90-Day Inhalation.........................................................

yes

yes

yes

no

no

yes

yes

yes

---

no

870.3700 Developmental Toxicity (rodent) .................................

870.3700 Developmental Toxicity (nonrodent) ...........................

870.3800 Reproduction ................................................................

yes

yes

yes

yes

yes

yes

870.4100 Chronic Toxicity (rodent).............................................

870.4100 Chronic Toxicity (nonrodent).......................................

870.4200 Oncogenicity (rat).........................................................

870.4200 Oncogenicity (mouse) ..................................................

870.4300 Chronic/Oncogenicity (mouse).....................................

870.4500 Chronic/Oncogenicity (rat)...........................................

yes

yes

yes

yes

yes

yes

yes

yes

yes

yes

yes

yes

870.5100 Mutagenicity—Gene Mutation - bacterial....................

870.5300 Mutagenicity—Gene Mutation - mammalian...............

yes

yes

yes

yes

870.5375 Mutagenicity—Structural Chromosomal Aberrations..

870.5385 Mutagenicity—Structural Chromosomal Aberrations..

870.5395 Mutagenicity—Other Genotoxic Effects......................

870.5550 Mutagenicity—Other Genotoxic Effects......................

yes

yes

yes

yes

Yes

yes

yes

yes

870.6100 Acute Delayed Neurotox. (hen)....................................

870.6100 90-Day Neurotoxicity (hen)..........................................

870.6200 Acute Neurotox. Screening Battery (rat)......................

870.6200 Chronic Neurotox. Screening Battery (rat)...................

870.6300 Develop. Neuro.............................................................

yes

no

yes

yes

no

yes

---

no

a

no

a

---

870.7485 General Metabolism .....................................................

870.7600 Dermal Penetration.......................................................

870.7800 Immunotoxicity

yes

no

yes

yes

---

no

a Based on the decisions of HASPOC, the requirement for the acute and subchronic neurotoxicity battery has been 

waived (D. Smegal, 2012, TXR No. 0055275).
Page 16 of 36

Table 4: Acute Toxicity Studies for Trifluralin, Technical

Guideline 

No. Study Type MRID No. Results

Toxicity 

Category

870.1100 Acute Oral (Rat) 00157486 (1985)

Acceptable/Guideline

LD50 > 5000 mg/kg

IV

870.1200 Acute Dermal (Rat) 00157482 (1985)

Acceptable/Guideline

LD50 > 2000 mg/kg

III

 870.1200 Acute Dermal (Rabbit)

00158820 (1985)

Acceptable/guideline

LD50 > 2000 mg/kg

 III

 870.1200 Acute Dermal (Rabbit) 40822202 (1988)

Acceptable/guideline

LD50 > 5000 mg/kg

 IV

870.1300 Acute Inhalation (Rat) 00155261 (1982)

Acceptable/guideline

LC50 > 4660 mg/m3, 4.66 

mg/L

IV

870.2400 Primary Eye Irritation 

(Rabbit)

00157483 (1985)

Acceptable/Guideline

Conjunctival redness at 

24hr, cleared by 4 days

III

870.2500 Primary Skin Irritation 00157485 (1985)

Acceptable/Guideline

Not an irritant

IV

870.2600 Dermal Sensitization 00157484 (1985)

Acceptable/Guideline

Sensitizing agent

N/A

Table 5: Toxicity Profile for Trifluralin

Guideline No./ Study 

Type

MRID No. (year)/ Classification 

/Doses

Comments

870.3100

2-Week R-F Feeding -

Rats (male)

00157154 (1983)

0, 6500 ppm

range-finding study for 00157156 

(1985), 41038301 (1986)

Acceptable/Nonguideline

NOAEL = not achieved

LOAEL = 6500 ppm based on renal epith damage,

urine triple phosphates crystals and urinary 

sediment

870.3100

90-Day Oral toxicity -

Rat

00151906 (1980)

0, 800, 2000, or 5000 ppm

M: 0, 59, 154, and 392 mg/kg/day 

NOAEL = 2000 ppm (154/168 mg/kg/day, M/F)

LOAEL = 5000 (392/421 mg/kg/day, M/F)

Based on minor decreases in overall body weight 

gains and food consumption in males and females, 
Page 17 of 36

Guideline No./ Study 

Type

MRID No. (year)/ Classification 

/Doses

Comments

F: 0, 69, 168, and 421 mg/kg/day

Acceptable/Guideline

decreased hemoglobin, alkaline phosphatase, and 

alanine aminotransferase in the males, and 

increased absolute and relative (to body) liver 

weights in males and females. 

870.3200

21/28-Day dermal 

toxicity-rabbit

41993810 (1991)

0, 100, 500, or 1000 mg/kg /day,

[formulation containing 35.8% 

trifluralin and 2.6% XRD-498]

Acceptable/Guideline

Systemic NOAEL =1000 mg/kg/day

Systemic LOAEL = Not achieved

Dermal NOAEL = Not achieved

Dermal LOAEL = 100 mg/kg/day, 

edema, and/or scaling and fissuring 100 mg/kg/day 

based skin irritation

870.3200

31-Day dermal toxicityrat

00153171 (1982)

0, 40, 200, or 1000 mg/kg/day

Acceptable/Guideline

Systemic NOAEL = 1000 mg/kg/day (limit dose)

Systemic LOAEL = not achieved

Dermal NOAEL = 40 mg/kg/day.

Dermal LOAEL = 200 mg/kg/day based on subepidermal inflammation and ulcerations. 

870.3200

21/28-Day dermal 

toxicity-rat

00152888 (1985)

0, 1000 mg/kg/day (limit dose)

Acceptable/Guideline

Systemic NOAEL = 1000 mg/kg/day.

Systemic LOAEL = Not achieved

Dermal NOAEL= Not achieved

Dermal LOAEL = 1000 mg/kg/day (limit dose) 

based on erythema, edema, and 

desquamination of the treated skin. 

870.3465

30-Day inhalation 

toxicity

40392312 (1987) reformat of 

00151904 (1982) 

0, 100, 301, 1006 mg/m3 

(6 hours/day 5 days/week for up to 

30 days)

Acceptable/Nonguideline

NOAEL = 301 mg/m3

LOAEL = 1006 mg/m3based on increased bilirubin 

in females and incidences of dyspnea and 

ruffled fur in males and females. 

870.3700 [83-3(a)]

Developmental Toxicity 

Study - Rat

00151899 (1983), 00159620 

(1986), 40392310 (1987)

0, 20, 100, 500 mg/kg/day

Acceptable/Guideline

Systemic Maternal NOAEL = 100 mg/kg/day

Systemic Maternal LOAEL = 500 mg/kg/day 

based on mortality, clinical signs, decreased body 

weight gains, decreased food consumption, and 

increased liver and spleen weights,

Developmental NOAEL =100 mg/kg/day.

Developmental LOAEL = 500 mg/kg/day based on

reduced ossification of the vertebrae and ribs and 

thickened, wavy or bent ribs and increased 

incidences of resorptions

870.3700 [83-3(a)] 00152419 (1984)

0, 100, 225, 495, or 1000 

Maternal NOAEL = 495 mg/kg/day

Maternal LOAEL = 1000 mg/kg/day based
Page 18 of 36

Guideline No./ Study 

Type

MRID No. (year)/ Classification 

/Doses

Comments

Developmental Toxicity 

Study - Rat

mg/kg/day

Acceptable/Guideline 

decreased body weights and decreased food 

consumption. 

Offspring NOAEL = 495 mg/kg/day

Offspring LOAEL = 1000 mg/kg/day based on

decreased fetal body weights. 

Developmental NOAEL = 1000 mg/kg/day

Developmental LOAEL was not established.

870.3700 [83-3(b)]

Developmental Toxicity -

Rabbit

00152421 (1984)

0, 100, 225, 500 mg/kg/day

Acceptable/Guideline 

Maternal NOAEL = 100 mg/kg/day

Maternal LOAEL = 225 mg/kg/day based on 

abortions, macroscopic changes in the liver and 

lungs, and decreased food consumption. 

Developmental NOAEL = 100 mg/kg/day

Developmental LOAEL = 225 mg/kg based on 

abortions. 

870.3800 [83-4]

2-Gen Repro - Rat

00151901 (1984)

00151902 (1984) Feed analysis

00151903 (1984) Path

0, 200, 650, 2000 ppm

0, 20, 32.5, 200 mg/kg/day

(1 ppm = 0.5 mg/kg/day)

Acceptable/Guideline

Parental NOAEL = 200 ppm (10 mg/kg/day).

Parental LOAEL = 650 ppm (32.5 mg/kg/day)

based on mortality due to acute renal failure and 

increased lesions of the renal proximal tubules in 

the F1 females; increased relative (to body) weights 

of the liver, kidney (males), and testes in both 

generations. 

Offspring NOAEL = 200 ppm (10 mg/kg/day)

Offspring LOAEL = 650 ppm (32.5

mg/kg/day) based on decreased pup weights in both 

generations and increased relative to body liver 

weights in the F2b females

Repro NOAEL = 2000 ppm (100 mg/kg/day)

Repro LOAEL = Not established. 
Page 19 of 36

Guideline No./ Study 

Type

MRID No. (year)/ Classification 

/Doses

Comments

870.3800 [83-4]

2-Gen Repro - Rat

40405007 (1987) 

0, 50, 450, 4000 ppm

M: 0, 3.9, 35, 295 mg/kg/day

F: 0, 4.7, 42, 337 mg/kg/day 

Acceptable/Guideline

Parental NOAEL = 450 ppm [35/42 mg/kg/day

 M/F]

Parental LOAEL = 4000 ppm [295/337 mg/kg/day M/F] 

based on decreased body weights, body weight gains, 

food consumption, and food 

efficiency in males and females of both generations; 

decreased ovary weights in both generations; colon 

distension in the F1 males; and uterine atrophy in the 

females of both generations.

Offspring NOAEL = 450 ppm (35/42 mg/kg/day M/F]

Offspring LOAEL = 4000 ppm [295/337mg/kg/day

, M/F] based on decreased pup weight

in F1a litters

Repro NOAEL = 450 ppm (35/42 mg/kg/day)

Repro LOAEL = 4000 ppm [295/337 mg/kg/day , M/F), bas

870.4100 [83-1(b)]

1-Year Oral (capsule) 

Study - Dog

00151908(1984), 00159618 (1985)

0, 30, 150, or 750 ppm

0.0, 0.8, 3.8, 18.8 mg/kg /day

Acceptable/guideline

NOAEL =30 ppm (0.8 mg/kg/day

LOAEL = 150 ppm (3.8 mg/kg/day) based on increased a

870.4100 [83-1(b)] 42447001 (1992) Systemic NOAEL = 2.4 mg/kg/day
Page 20 of 36

Guideline No./ Study 

Type

MRID No. (year)/ Classification 

/Doses

Comments

1-Year Oral (capsule) 

Study - Dog 0, 0.75, 2.4, 40 mg/kg/day 

Acceptable/Guideline

Systemic LOAEL = 40 mg/kg/day, based on increased 

frequency of abnormal stool and pigment deposition in 

the kidney and liver in males and females, decreased 

body weights and body weight gains, and on decreased 

erythrocytes and hemoglobin and increased 

thrombocytes in males. 

870.4300 [83-5(a)]

24- Month Chronic 

Toxicity/ Carcinogenicity 

Study - Rat

00162457 (1985), 00162458 

(1985)

0, 200, 800, or 3200 ppm

M: 0, 10, 40, and 169 mg/kg/day

F: 0, 13, 53, and 219 mg/kg/day

Acceptable/guideline

NOAEL = 800 ppm (40/53 mg/kg/day M/F).

LOAEL = 3200 ppm (169/219 mg/kg/day M/F) based on d

At the doses tested, the carcinogenic potential of 

trifluralin was negative. Dosing was considered 

adequate based on differences in body weight and body 

weight gains

870.4300 [83-2(a)]

24- Month 

Carcinogenicity Study -

Mouse

00158935 (1986), 40392313 

(1987)

0, 50, 200, or 800 ppm

M: 0, 7.5, 29, and 118 mg/kg/day

F: 0, 10.5, 41, and 165 mg/kg/day

Unacceptable/guideline

Systemic NOAEL = 800 ppm (118/165 mg/kg/day in 

males/females)

Systemic LOAEL = Not achieved 

At the doses tested, the carcinogenic potential of 

trifluralin was negative. Dosing was considered 

inadequate as a toxic effect was not observed, and the 

limit dose was not tested

870.5100

Bacterial reverse gene 

mutation assay

MRID 00148345 (1984) 

Acceptable/Guideline

Trifluralin was tested up to the limit of solubility (400 

μg/plate -S9; 800 μg/plate +S9). No cytotoxicity was 

observed in any strain at up to 800 (+S9) or 400 (-S9) 

μg/plate. No treatment-related increases in revertant 

colonies were observed at any dose in any strain (±S9). 

The positive controls induced the appropriate responses. 

There was no evidence of induced mutant colonies 

over background
Page 21 of 36

Guideline No./ Study 

Type

MRID No. (year)/ Classification 

/Doses

Comments

870.5100

Bacterial reverse gene 

mutation assay

MRID 40334707 (1987)

Acceptable/Guideline

In a reverse gene mutation assay in bacteria (MRID 

40334707), Salmonella typhimurium strains TA98, 

TA100, TA1535, TA1537, and TA1538 were exposed 

to trifluralin (96.8% a.i., Lot/Batch #: 335/336) in 

dimethyl sulfoxide (DMSO) at concentrations of 30, 

100, 300, 1000, 3000, or 10,000 μg/plate in the presence 

and absence of mammalian metabolic activation (S9). 

The standard plate incorporation method was used. 

Standard strain-specific mutagens served as positive 

controls.

Trifluralin was tested up to the limit of solubility (3000 

μg/plate, +/-S9). No cytotoxicity was observed in any 

strain at up to 3000 μg/plate (+/-S9). No treatmentrelated increases in revertant colonies were observed at 

any dose in any strain (+/-S9). The positive controls 

induced the appropriate responses. There was no 

evidence of induced mutant colonies over 

background.

870.5100

Bacterial reverse gene 

mutation assay

MRID 00153173 (1979) 

Acceptable/Guideline

In a reverse gene mutation assay in bacteria (MRID 

00153173), Salmonella typhimurium strains TA98, 

TA100, TA1535, TA1537, and TA1538 were exposed 

to HOE 38474 (trifluralin; purity not reported; 

Lot/Batch #: OH AT204) in DMSO at concentrations of 

0, 4, 20, 100, 500, 2500, or 10,000 μg/plate (+/-S9). 

Standard strain-specific positive controls were used.

HOE 38474 was tested up to the limit dose (10,000 

μg/plate, +/-S9). No treatment-related increases in 

revertant colonies were observed at any dose in any 

strain (±S9). The positive controls induced the 

appropriate responses. There was no evidence of 

induced mutant colonies over background.

870.5250

Gene Mutation Assay -

Yeast

MRID 00151898 ((1982)

Acceptable/Guideline

The test material was tested up to the limit of solubility 

(1000 mg/L); however, no solubility data were 

provided. No treatment-related increases in mutation 

frequency were observed at any dose with or without 

S9-activation. The positive controls induced the 

appropriate response. There was no concentrationrelated positive response of induced mutant colonies 

over background.
Page 22 of 36

Guideline No./ Study 

Type

MRID No. (year)/ Classification 

/Doses

Comments

870.5300

In vitro mammalian cell 

gene mutation assay

MRID 00126661

Acceptable/Guideline

In a mammalian cell gene mutation assay at the 

thymidine kinase (TK) locus, mouse lymphoma 

L5178Y cells cultured in vitro were exposed to 

trifluralin (95.0% a.i.; Lot/Batch #: 00554AP2) in 

DMSO for 4 hours at 8 concentrations ranging from 0.5 

to 20 μg/mL (individual doses not reported) both in the 

presence and absence of S9-activation. 

Trifluralin was tested up to cytotoxic concentrations (20 

μg/mL, +/-S9). No treatment-related increases in 

mutation frequency were observed at any dose 

compared to controls. The positive controls induced the 

appropriate response. There was no concentrationrelated positive 

response of induced mutant colonies over 

background.

870.5300

Mammalian Cell Forward 

Gene Mutation Assay

MRID 40765601 (1988)

Acceptable/Guideline

In a mammalian cell gene mutation assay at the HGPRT 

locus (MRID 40765601), Chinese hamster ovary (CHO) 

cells cultured in vitro were exposed to trifluralin (97.6% 

a.i.; Lot/Batch #: 39) in dimethyl sulfoxide for 4 hours 

at concentrations of 50, 100, 150, 200, 300, 400, or 500 

μg/mL (Trial 1, -S9); 50, 100, 200, 300, 500, 600, or

700 μg/mL (Trial 2, -S9); 50, 100, 200, 250, 300, 400, 

or 500 μg/mL (Trial 1, +S9); and 50, 100, 200, 300, 

400, 500, or 600 μg/mL (Trial 2, +S9).

Trifluralin was tested up to cytotoxic concentrations 

(>=200 μg/mL, +/-S9) and the limit of solubility (>=100 

μg/mL, +/-S9). No treatment-related increases in 

mutant frequency were observed in either trial in the 

presence or absence of S9. The positive controls 

induced the appropriate response. There was no 

evidence of induced mutant colonies over 

background in the presence or absence of S9-

activation.
Page 23 of 36

Guideline No./ Study 

Type

MRID No. (year)/ Classification 

/Doses

Comments

870.5300

Mammalian Cell Forward 

Gene Mutation Assay

MRID 00148318 (1984)

Acceptable/Guideline

In a mammalian cell gene mutation assay at the HGPRT 

locus (MRID 00148318), Chinese hamster ovary (CHO) 

cells cultured in vitro were exposed to triflurex technical 

(trifluralin; purity not reported; Lot/Batch #: not 

reported) in ethanol for 4 hours at concentrations of 10, 

50, 100, 200, 300, 400, or 500 μg/mL (-S9) and 50, 100, 

200, 300, 400, 500, or 600 μg/mL (+S9).

Triflurex technical was tested up to cytotoxic 

concentrations (>=200 μg/mL, -S9 and >=300 μg/mL, 

+S9) and the limit of solubility (>=100 μg/mL, +/-S9). 

No treatment-related increases in mutant frequency 

were observed in either trial in the presence or absence 

of S9. The positive controls induced the appropriate 

response. There was no evidence of induced mutant 

colonies over background in the presence or absence 

of S9-activation.

870.5385

In Vivo Mammalian 

Cytogenetics [Bone 

Marrow/Spermatogonial 

Aberration Test]

MRID 40765603 (1988)

Acceptable/Guideline

In a bone marrow/spermatogonial chromosome 

aberration assay (MRID 40765603), ICR mice (10 

males/dose, spermatogonial tissue; and 5/sex/dose, bone 

marrow) were dosed once daily via gavage (10 mL/kg) 

with trifluralin (97.6% a.i., Lot/Batch No 39) in corn oil 

at doses of 0, 62.5, 208, or 625 mg/kg for 5 consecutive 

days. Bone marrow and spermatogonial cells were 

harvested at 4.5 hours after the last treatment. 

Mortalities were observed in the 625 mg/kg females 

(2/5 treated vs. 1/5 controls), and at 62.5 mg/kg in the 

males (2/10 treated vs. 1/10 controls) and females (2/5 

treated vs. 1/5 controls). Clinical signs of toxicity 

(lethargy, swollen neck, and yellow stains around the 

mouth and perianal area) were also observed at >=62.5 

mg/kg. No statistically significant increases in the 

percent of aberrant cells were observed at any dose in 

either sex in the bone marrow assay or in the males in 

the spermatogonial assay. Trifluralin was tested at an 

adequate dose based on mortalities observed at >=62.5 

mg/kg. The positive control induced the appropriate 

response. There was no evidence of chromosome 

aberration induced over background
Page 24 of 36

Guideline No./ Study 

Type

MRID No. (year)/ Classification 

/Doses

Comments

870.5385

In Vivo Mammalian 

Cytogenetics [Bone 

Marrow Chromosome 

Aberration Test]

MRID 00148320

Acceptable/Guideline

In a bone marrow chromosome aberration assay (MRID 

00148320), 5 Sprague-Dawley (HSD:([SD] BR) 

rats/sex/dose/sacrifice time were treated once via oral 

gavage with Triflurex technical (trifluralin; 97.3% a.i.; 

Batch #: 5320), in corn oil at doses of 0, 500, 1650, or 

5000 mg/kg. Bone marrow cells were harvested at 6, 

24, or 48 hours after treatment.

Mortality was observed at 1650 (3/15 males and 5/15 

females) and 5000 (2/15 males and 1/15 females) mg/kg 

upon initial dosing; however, these animals were 

replaced and only one replacement 1650 mg/kg female 

in the 48 hour group died after 

dosing. Triflurex technical induced minimal bone 

marrow toxicity (as indicated by decreased mitotic 

index) at 500 mg/kg in males and 1650 mg/kg in 

females. Dosing was considered adequate based on 

bone marrow toxicity and that the animals were dosed 

above the limit dose (2000 mg/kg). No statistically 

significant increases in the percent of aberrant cells 

were observed at any dose or sampling time compared 

to concurrent controls. The positive control induced the 

appropriate response. There was no evidence of 

chromosome aberration induced over background.

870.5395

In vivo Mouse 

Erythrocyte Micronucleus 

assay

MRID 00151895 (1981)

Acceptable/Guideline

In a bone marrow micronucleus assay, 5 NMRI 

mice/sex/dose were treated via oral gavage with HOE 

38474 (Trifluralin; 98.3% a.i., Lot/Batch #: OH 

AT208), in sesame oil at doses of 0, 25, 250, or 2500 

mg/kg on two consecutive days (24 hours apart). Bone 

marrow cells were harvested at 6 hours after the last 

treatment.

No unscheduled deaths occurred during the study. No 

clinical signs of toxicity were observed. No statistically 

significant differences in the number of micronucleated 

polychromatic erythrocytes (MPCE) or normocytes and 

no decrease in polychromatic erythrocyte to normocyte 

(PCE:NCE) ratios were noted in the treated animals 

compared to controls; however, only individual data 

were provided. Additionally, although no evidence of 

cytotoxicity (decreased PCE: NCE) was noted in the 

bone marrow, the animals were sufficiently dosed (the 

limit dose was given twice). The test material was 
Page 25 of 36

Guideline No./ Study 

Type

MRID No. (year)/ Classification 

/Doses

Comments

absorbed as indicated by the presence of orange urine in 

the 2500 mg/kg animals. The positive control induced 

the appropriate response. There was no significant 

increase in the frequency of micronucleated 

polychromatic erythrocytes in bone marrow 

compared to controls.
Page 26 of 36

Guideline No./ Study 

Type

MRID No. (year)/ Classification 

/Doses

Comments

870.5450

Dominant Lethal - Rat 

MRID 00148319 (1984)

Acceptable/Guideline

In a dominant lethal assay (MRID 00148319), groups 

of 20 male Sprague-Dawley (CD) rats/dose were treated 

once daily via gavage (1.0 mL/dose) with Triflurex 

technical (trifluralin; 97.3% a.i.; Batch #: 5320), in corn 

oil for 5 consecutive days at doses of 0, 100, 333, or 

1000 mg/kg/day (total doses of 0, 500, 1665, or 5000 

mg/kg). Beginning two days after the last exposure, 

each male was mated sequentially to two untreated 

female rats per week for seven weeks. At 14 days after 

the midpoint of each mating week, the females were 

killed, determined to be pregnant or not pregnant, and 

the number of corpora lutea, living, dead, and total 

implantations was determined. On the fifth day of 

dosing, the positive control males were given a single 

dose of triethylenemelamine (TEM; 0.3 mg/kg, i.p. in 

0.9% saline).

One 1000 mg/kg male (#8476) was found dead 72 hours 

after the last treatment. Triflurex technical was tested at 

the limit dose (5000 mg/kg = 1000 mg/kg/day X 5 

days). There were no treatment-related effects on 

fertility, number of implants, pre-implantation losses, 

number of dead implants, number of females with 1 or 

2 dead implants, or ratio of dead implants to total 

implants at any dose in the study. The positive control 

induced the appropriate response. There was no timerelated positive response of increased pre- or postimplantation loss compared to controls.
Page 27 of 36

Guideline No./ Study 

Type

MRID No. (year)/ Classification 

/Doses

Comments

870.5450

Dominant Lethal -

Mouse

MRID 00151896 (1984)

Acceptable/Guideline

In a dominant lethal assay (MRID 00151896), 30 male 

NMRI mice were dosed once daily for 5 consecutive 

days via oral gavage (5 mL/kg) with HOE 38474 

(trifluralin; 98.3% a.i.; Lot/Batch #: OHZD99002), in 

sesame oil at concentrations of 0, 10, 100, or 1000 

mg/kg. After the final treatment, each male was mated 

with 13 untreated females during separate 4-day 

intervals over a 52 day period.

No treatment-related mortalities were noted during the 

study. No treatment-related effects on clinical signs, 

body weight, fertilization rate, and pre- or postimplantation loss were observed; however, no data were 

provided. The positive control 

(cyclophosphamide) increased the number of postimplantation fetal losses. There was no time-related 

positive response of increased pre- or postimplantation loss compared to controls.

870.5550

Unscheduled DNA 

synthesis in mammalian 

cell culture

MRID 40765602 (1988)

Acceptable/Guideline

In an unscheduled DNA synthesis assay (MRID), 

primary rat hepatocyte cultures were exposed to 

trifluralin (97.6% a.i.; Lot/Batch #: 39) in DMSO for 

18-19 hours at concentrations of 0, 0.032, 0.214, 0.404, 

0.917, 2.22, 4.36, 8.52, 21.3, 42.9, 88.0, 448, or 898 

μg/mL. Fifteen doses ranging from 0.032-898 μg/mL 

were used in each assay; however, the three doses 

between 0.032 and 0.214 μg/mL were not reported.

Trifluralin was tested up to cytotoxic levels (determined 

by trypan blue exclusion), 88.0 μg/mL in rat #1 and 

42.9 μg/mL in rat #2. There were no marked increases 

observed in the mean NNG or percent cells in repair at 

any dose in either trial. The positive controls induced 

marked increases in mean NNG and the percent of cells 

in repair. There was no evidence that unscheduled 

DNA synthesis, as determined by radioactive tracer 

procedures (nuclear silver grain counts), was 

induced.
Page 28 of 36

Guideline No./ Study 

Type

MRID No. (year)/ Classification 

/Doses

Comments

870.5550

Unscheduled DNA 

synthesis in mammalian 

cell culture

MRID 00151894 (1982)

Acceptable/Guideline

In an unscheduled DNA synthesis assay (MRID 

00151894), HeLa cell cultures were exposed to HOE 

38474 (trifluralin, 98.3% a.i.; Lot/Batch #: OH AT 208) 

in DMSO for 1 hour at concentrations of 0, 50, 100 or 

500 μg/mL both in the presence and absence of S9-

activation.

HOE 38474 was tested up to cytotoxic concentrations 

(>= 50 μg/mL, +/-S9). No statistically significant 

increases in mean counts per minute of the test material 

with hydroxyurea were noted compared to concurrent 

solvent controls at any dose level, either in the presence 

or absence of S9-activation. The positive controls 

induced the appropriate response. There was no 

evidence that unscheduled DNA synthesis, as 

determined by liquid scintillation counting 

procedures, was induced.

870.5900

In vivo Sister Chromatid 

Exchange (SCE) Assay

MRID 00133426 (1983)

Acceptable/Guideline

In a mammalian cell cytogenetics assay [SCE induction] 

using the BrdU tablet method , groups of 3 female 

Chinese hamsters/dose were exposed once via gavage 

(10 mL/kg) to trifluralin (95.0% a.i., Lot/batch No 

00554AP2) in DMSO and 10% acacia at concentrations 

of 200, 300, 400, or 500 mg/kg at 5 hours following 

BrdU tablet implantation. Bone marrow was collected 

at 21 hours after treatment.

Trifluralin was tested up to cytotoxic 

concentrations (>=400 mg/kg). Cytotoxicity (as 

indicated by an increase in the number of first division 

metaphase figures) was observed in all animals at 

>=400 mg/kg. No statistically significant increases in 

SCE frequency were observed at any dose compared to 

controls. The positive control induced the appropriate 

response. There was no evidence of SCE induced

over background

870.7845 (85-1)

Metabolism - Rat

Urinary metabolites

41218901 (1989) 

Acceptable/Guideline

There was no sex-dependent effect on metabolic 

profiles. A minimum of 20-30 non-conjugated 

metabolites and an additional 10-20 conjugated 

metabolites were present in the urine, but no parent 

compound was detected. Information on the percentage 

of the administered dose excreted in the urine was not 
Page 29 of 36

Guideline No./ Study 

Type

MRID No. (year)/ Classification 

/Doses

Comments

provided. However, no single metabolite accounted for 

more than 8-10% of the total urinary radioactivity, and 

the majority of the metabolites were present at 1-2% of 

the total urinary radioactivity. Thus, almost all of the 

metabolites were minor (<5% of the total radioactive 

dose). Metabolite F1B was found at 8.2-8.9% of the 

total urinary radioactivity in both sexes, and Metabolite 

F2, N-[(3-(acetylamino)-2-amino-5-

(trifluoromethyl)phenyl] acetamide, was found at 4.0-

5.2%. Metabolite F1B was partially characterized as 

retaining the trifluoromethyl groups, the two equivalent 

aromatic protons, and the two nitro groups, but the 

propyl groups were lost. Ten other metabolites were 

identified (<0.1-3.7% of total urinary radioactivity, each 

compound in each sex). Two additional metabolites 

were partially characterized (0.1-2.6% of total urinary 

radioactivity, each compound in each sex).

Four metabolic pathways were identified as follows: (i) 

oxidative N-dealkylation of one or both propyl groups 

and metabolites which were hydroxylated on the propyl 

side chain; (ii) reduction of one or both nitro groups to 

the corresponding amine; (iii) cyclization reactions to 

give a variety of substituted and unsubstituted 

benzimidazole metabolites; and (iv) conjugation 

reactions, including acetylation of the reduced nitro 

groups, sulfate, and glucuronic acid conjugates.

Special study

3-Mo Feeding - Rat with

Urinalysis study

00157156 (1985), 40138301(1986)

41086101 (1989)

0, 50, 200, 800, 3200, and 6400 

ppm

0, 2.6, 10.7, 42.2, 170.2, and 342.1 

mg/kg/day

Acceptable/Nonguideline

NOAEL = 200 ppm (10.7 mg/kg/day)

LOAEL for nephrotoxicity = 800 ppm (42.2

mg/kg/day), based on the presence of cortical 

tubular cytoplasmic hyaline droplets; increased 

total protein, AST, and LDH in the urine; and 

increased urinary volume upon protein 

electrophoresis and urinalysis.
Page 30 of 36

Table 6.1: Summary of Toxicological Points of Departure and Endpoints for Trifluralin for Used in Dietary and Nondietary Human Health Risk Assessments

Exposure/

Scenario

Point of 

Departure

Uncertainty 

Factors

Level of Concern for 

Risk Assessment Study and Toxicological Effects

Acute Dietary

(Females 13-50 

years of age)

NOAEL = 100 

mg/kg/day

UFA=10x

UFH=10x

FQPA SF 

=1 

100 mg/kg/day NOAEL 

 100 (UF)

aRfD = 1.0 mg/kg/day 

Developmental Toxicity Study – Rat

LOAEL = 500 mg/kg/day, based 

on increased total litter 

resorptions

Acute Dietary

(General 

population, 

including infants 

and children)

No endpoints identified from the available developments toxicity studies (rat and rabbit) appropriate for 

an acute dietary assessment for trifluralin.

Chronic Dietary

(All populations)

NOAEL = 

2.4 mg/kg/day

UFA=10x

UFH=10x

FQPA SF 

=1 

 2.4mg/kg/day NOAEL 

 100 (UF)

cRfD = 0.024 mg/kg/day 

Chronic (capsule) Toxicity – Dog

LOAEL = 40 mg/kg/day, based on 

increased frequency of abnormal 

stool, decreased body weights and 

body weight gains, and decreased 

erythrocytes and hemoglobin and 

increased thrombocytes (males)

Incidental Oral 

Short-Term (1-30 

days)

NOAEL = 

10 mg/kg/day

UFA=10x

UFH=10x

FQPA SF 

=1

Residential LOC for MOE 

= 100

Two-generation Reproduction Study 

in Rats

LOAEL = 32.5 mg/kg/day, based 

on decreased pup weights in both 

generations

Incidental Oral 

Intermediate-Term 

(1-6 months)

NOAEL = 

10 mg/kg/day

UFA=10x

UFH=10x

FQPA SF 

=1

Residential LOC for MOE 

= 100

Special Urinalysis Study in Rats

LOAEL = 40 mg/kg/day, based on 

the presence of tubular 

cytoplasmic hyaline droplets; 

increased total protein, AST, and 

LDH in the urine; albumin α1-

globulin and α2-globulin observed 

by urine electrophoresis; and 

increased urinary volume 

Dermal

Short-Term (1-30 

days)

No quantification required since there was no systemic toxicity at the limit dose in the dermal toxicity 

study. There are no developmental toxicity concerns. The HIARC also recommends that the products 

containing trifluralin should be labeled as SENSITIZER
Page 31 of 36

Table 6.1: Summary of Toxicological Points of Departure and Endpoints for Trifluralin for Used in Dietary and Nondietary Human Health Risk Assessments

Dermal 

Intermediate-term 

(1-6 months)

NOAEL = 10 

mg/kg/day

(Dermal 

Absorption rate = 

3 %)

UFA=10x

UFH=10x

FQPA SF 

=1

Residential LOC for MOE 

= 100

Special Urinalysis Study in Rats

LOAEL = 40 mg/kg/day, based on 

the presence of tubular 

cytoplasmic hyaline droplets; 

increased total protein, AST, and 

LDH in the urine; albumin α1-

globulin and α2-globulin observed 

by urine electrophoresis; and 

increased urinary volume 

Dermal Long-term 

(>6 months)

NOAEL = 

2.4 mg/kg/day

(Dermal 

Absorption rate = 

3 % when 

appropriate)

UFA=10x

UFH=10x

FQPA SF 

=1

Residential LOC for MOE 

= 100

Chronic (capsule) Toxicity – Dog

LOAEL = 40 mg/kg/day, based on 

increased frequency of abnormal 

stool, decreased body weights and 

body weight gains, and decreased 

erythrocytes and hemoglobin and 

increased thrombocytes (males)

Dermal Long-term 

(>6 months) Long-term dermal exposure is not expected based on the use pattern for paclobutrazol.

Inhalation Shortterm (1-30 days)

NOAEL = 81 

mg/kg/day)

UFA=10x

UFH=10x

FQPA SF 

=1

Residential LOC for MOE 

= 100

30-Day Inhalation Study - Rat 

LOAEL = 270 mg/kg/day, based 

on increased methemoglobin and 

bilirubin in females and the 

incidence of dyspenea and ruffled 

fur in males and females

Inhalation 

Intermediate-term 

(1-6 months)

NOAEL = 100 

mg/kg/day 

(Inhalation 

absorption

rate = 100%)

UFA=10x

UFH=10x

FQPA SF 

=1

Residential for MOE = 

100

Special Urinalysis Study in Rats

NOAEL = 40 mg/kg/day, based on 

the presence of tubular 

cytoplasmic hyaline droplets; 

increased total protein, AST, and 

LDH in the urine; albumin α1-

globulin and α 2-globulin observed 

by urine electrophoresis; and 

increased urinary volume

Inhalation Longterm (1-6 months)

NOAEL = 100 

mg/kg/day 

(Inhalation 

absorption

rate = 100%)

UFA=10x

UFH=10x

FQPA SF 

=1

Residential LOC for MOE 

= 100

Chronic (capsule) Toxicity – Dog

LOAEL = 40 mg/kg/day, based on 

increased frequency of abnormal 

stool, decreased body weights and 

body weight gains, and decreased 

erythrocytes and hemoglobin and 

increased thrombocytes (males)

Cancer (oral, 

dermal, inhalation)

Classification: Group C (“Possible” Human Carcinogen)

Q 1 

* = 2.96 X 10-3 (mg/kg/day)-1 (TXR No. 00052534) 
Page 32 of 36

1 Explanation of Abbreviations: Point of Departure (PoD) = A data point or an estimated point that is 

derived from observed dose-response data and used to mark the beginning of extrapolation to determine 

risk associated with lower environmentally relevant human exposures. NOAEL = no observed adverse 

effect level. LOAEL = lowest observed adverse effect level. UF = uncertainty factor. UFA = extrapolation 

from animal to human (interspecies). UFA = extrapolation from animal to human (interspecies). UFH = 

potential variation in sensitivity among members of the human population (intraspecies). UFDB = database 

uncertainty, lack of neurotoxicity (acute and subchronic) and immunotoxicity studies, FQPA SF = FQPA 

safety factor. MOE = margin of exposure. LOC = level of concern. 
Page 33 of 36

Table 6.2: Summary of Toxicological Points of Departure and Endpoints for Trifluralin for Used in Residential/ 

Occupational Human Health Risk Assessments

Exposure/

Scenario

Point of 

Departure

Uncertainty 

Factors

Level of Concern for 

Risk Assessment Study and Toxicological Effects

Dermal

Short-Term (1-30 

days)

No quantification required since there was no systemic toxicity at the limit dose in the dermal toxicity 

study. There are no developmental toxicity concerns. The HIARC also recommends that the products 

containing trifluralin should be labeled as SENSITIZER

Dermal 

Intermediate-term 

(1-6 months)

NOAEL = 10 

mg/kg/day

(Dermal 

Absorption rate = 

3 %)

UFA=10x

UFH=10x

FQPA SF 

=1

Residential LOC for MOE 

= 100

Special Urinalysis Study in Rats

LOAEL = 40 mg/kg/day, based 

on the presence of tubular 

cytoplasmic hyaline droplets; 

increased total protein, AST, and 

LDH in the urine; albumin α1-

globulin and α2-globulin 

observed by urine 

electrophoresis; and increased 

urinary volume 

Dermal Long-term 

(>6 months)

NOAEL = 

2.4 mg/kg/day

(Dermal 

Absorption rate = 

3 % when 

appropriate)

UFA=10x

UFH=10x

FQPA SF 

=1

Residential LOC for MOE 

= 100

Chronic (capsule) Toxicity – Dog

LOAEL = 40 mg/kg/day, based on 

increased frequency of abnormal 

stool, decreased body weights and 

body weight gains, and decreased 

erythrocytes and hemoglobin and 

increased thrombocytes (males)

Dermal Long-term 

(>6 months) Long-term dermal exposure is not expected based on the use pattern for paclobutrazol.

Inhalation Shortterm (1-30 days)

NOAEL = 81 

mg/kg/day)

UFA=10x

UFH=10x

FQPA SF 

=1

Residential LOC for MOE 

= 100

30-Day Inhalation Study - Rat 

LOAEL = 270 mg/kg/day, based 

on increased methemoglobin and 

bilirubin in females and the 

incidence of dyspenea and ruffled 

fur in males and females
Page 34 of 36

Table 6.2: Summary of Toxicological Points of Departure and Endpoints for Trifluralin for Used in Residential/ 

Occupational Human Health Risk Assessments

Inhalation 

Intermediate-term 

(1-6 months)

NOAEL = 100 

mg/kg/day 

(Inhalation 

absorption

rate = 100%)

UFA=10x

UFH=10x

FQPA SF 

=1

Residential for MOE = 

100

Special Urinalysis Study in Rats

NOAEL = 40 mg/kg/day, based 

on the presence of tubular 

cytoplasmic hyaline droplets; 

increased total protein, AST, and 

LDH in the urine; albumin α1-

globulin and α 2-globulin 

observed by urine 

electrophoresis; and increased 

urinary volume

Inhalation Longterm (1-6 months)

NOAEL = 100 

mg/kg/day 

(Inhalation 

absorption

rate = 100%)

UFA=10x

UFH=10x

FQPA SF 

=1

Residential LOC for MOE 

= 100

Chronic (capsule) Toxicity – Dog

LOAEL = 40 mg/kg/day, based on 

increased frequency of abnormal 

stool, decreased body weights and 

body weight gains, and decreased 

erythrocytes and hemoglobin and 

increased thrombocytes (males)

Cancer (oral, 

dermal, inhalation)

Classification: Group C (“Possible” Human Carcinogen)

Q 1 

* = 2.96 X 10-3 (mg/kg/day)-1 (TXR No. 00052534) 

1 Explanation of Abbreviations: Point of Departure (PoD) = A data point or an estimated point that 

is derived from observed dose-response data and used to mark the beginning of extrapolation to determine 

risk associated with lower environmentally relevant human exposures. NOAEL = no observed adverse 

effect level. LOAEL = lowest observed adverse effect level. UF = uncertainty factor. UFA = extrapolation 

from animal to human (interspecies). UFA = extrapolation from animal to human (interspecies). UFH = 

potential variation in sensitivity among members of the human population (intraspecies). UFDB = database 

uncertainty, lack of neurotoxicity (acute and subchronic) and immunotoxicity studies, FQPA SF = FQPA 

safety factor. MOE = margin of exposure. LOC = level of concern. 

Table 7. Trifluralin International Residue Limits 

Summary of US and International Tolerances and Maximum Residue Limits 

Residue Definition:

US Canada Mexico2 Codex

40 CFR 180.207:

Plant: α,α,α-trifluroro-2,6-dinitro-N,Ndipropyl-p-toluidine

Commodity1 Tolerance (ppm) /Maximum Residue Limit (mg/kg)

US Canada Mexico2 Codex

Alfalfa, forage 3.0

Alfalfa, hay 2.0

Almond, hulls 0.05

Asparagus 0.05

Barley, grain 0.05

Barley, hay 0.05

Barley, straw 0.05
Page 35 of 36

Table 7. Trifluralin International Residue Limits 

Summary of US and International Tolerances and Maximum Residue Limits 

Residue Definition:

US Canada Mexico2 Codex

Bean, mung, sprouts 2.0

Carrot, roots 1.0

Celery 0.05

Corn, field, forage 0.05

Corn, field, grain 0.05

Corn, field, stover 0.05

Cotton, gin byproducts 0.05

Cotton, undelinted seed 0.05

Endive 0.05

Flax, seed 0.05

Fruit, citrus, group 10 0.05

Fruit, stone, group 12 0.05

Grape 0.05

Hop, dried cones 0.05

Mustard, seed 0.05

Nut, tree, group 14 0.05

Okra 0.05

Peanut 0.05

Peanut, hay 0.05

Peppermint, oil 2.0

Peppermint, tops 0.05

Rapeseed, seed 0.05

Safflower, seed 0.05

Sorghum, grain forage 0.05

Sorghum, grain, grain 0.05

Sorghum, grain, stover 0.05

Spearmint, oil 0.05

Spearmint, tops 2.0

Sugarcane, cane 0.05

Sunflower, seed 0.05

Vegetable, brassica, leafy group 5 0.05

Vegetable, bulb, group 3 0.05

Vegetable, cucurbit, group 9 0.05

Vegetable, fruting, group 8 0.05

Vegetable, leaves of root and tuber, group 2 0.05

Vegetable, legume, group 6 0.05

Vegetable, root and tuber, group 1 except 

carrot

0.05

Wheat, grain 0.05

Wheat, straw 0.05

1

Includes only commodities of interest for this action.

2 Mexico adopts US tolerances and/or Codex MRLs for its export purposes.
Page 36 of 36

Table 8: HED Memoranda Relevant to Registration Review

Author Barcode/TXR # Date Title

R. Griffin D296628 05/07/2004 Trifluralin Human Health Risk 

Assessment

R. Griffin D296627 03/04/2004 Residue Chemistry Chapter for the 

TRED Document

D. Smegal D397497 03/06/2012 Summary of Hazard and Science 

Policy Council (HASPOC)

R.B. Jaeger TXR No. 0005578 04/11/1986 Peer Review of Trifluralin

R. Griffin TXR No. 0052534 05/11/2004

Revised Trifluralin Quantitative Risk 

Assessment (Q1*) Based on Fisher 

344 Rat Dietary Studies With 3⁄4 

Interspecies Scaling Factor

S. Piper D296628 08/10/2004

Anticipated Residues, Acute, 

Probabilistic, Chronic and Cancer 

Dietary Exposure Assessment for the 

RED

S.Piper D399348 02/29/2012 Response to DowAgroSciences’ 

Comments on the Human Health 

Risk Assessment and TRED

S.Piper D300064 03/09/2004 HED Metabolism Assessment 

Review Committee Decision 

Document

S. Recore D296625 05/06/2004 Residential Exposure Assessment and 

Recommendations for the Tolerance 

Reassessment Evaluation Decision 

(TRED) Document for Trifluralin

S. Recore D300239 05/12/2004 Review of “Dissipation of 

Transferable Residues of Benefin and 

Trifluralin on Turf Treated with a 

Formulation of the Pesticides”

S. Recore D397847 03/14/2012 Trifluralin Review of Human 

Incident

B. Phillips -- 12/01/2011 BEAD Chemical Profile for 

Registration Review