Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 1 of 39 

Data Requirement: PMRA Data Code: 9.8.4 (TGAI) or 9.8.6 (EP) 

EPA DP Barcode: 427855 

OECD Data Point: IIA 8.12 (TGAI) and IIIA 10.8.1.1 (EP) 

EPA Guideline: 850.4100 

Test material: Atrazine SC Purity: 43.0% (w/w) 

Common name: 

Chemical name: IUPAC: 

CAS name: 

CAS No.: 1912-24-9 

Synonyms: A8566A; G30027 SC (479.37)

Primary Reviewer: Joan Gaidos Signature: 

Senior Scientist, CDM Smith Date: 11/12/15 

Secondary Reviewer: Teri S. Myers Signature: 

Senior Scientist, CDM Smith Date: 11/16/15

Secondary Reviewer: Frank T. Farruggia, Ph.D. Date: 2-29-16 

{EPA/OECD/PMRA}

Reference/Submission No.: {.....................}

Company Code {............} [For PMRA]

Active Code {............} [For PMRA] 

Use Site Category: {............} [For PMRA] 

EPA PC Code 080803

Date Evaluation Completed: 29-02-2016 

CITATION: Martin J.A. Atrazine SC (A8566A) – Seedling Emergence Test with Extended Exposure to View 

Potential Recovery. Unpublished study performed by Smithers Viscient, Wareham, Massachusetts and sponsored 

by Syngenta crop Protection, LLC, Greensboro, North Carolina. Laboratory Study Number: 1781.7000. Study 

completed March 13, 2015. 

DISCLAIMER: This document provides guidance for EPA and PMRA reviewers on how to complete a data 

evaluation record after reviewing a scientific study concerning the acute toxicity of a pesticide to terrestrial vascular 

plants. It is not intended to prescribe conditions to any external party for conducting this study nor to establish 

absolute criteria regarding the assessment of whether the study is scientifically sound and whether the study satisfies 

any applicable data requirements. Reviewers are expected to review and to determine for each study, on a case-bycase basis, whether it is scientifically sound and provides sufficient information to satisfy applicable data 

requirements. Studies that fail to meet any of the conditions may be accepted, if appropriate; similarly, studies that 

meet all of the conditions may be rejected, if appropriate. In sum, the reviewer is to take into account the totality of 

factors related to the test methodology and results in determining the acceptability of the study. 

Digitally signed by FRANK FARRUGGIA 

DN: c=US, o=U.S. Government, 

ou=USEPA, ou=Staff, cn=FRANK 

FARRUGGIA, dnQualifier=0000048865 

Date: 2016.02.29 12:58:50 -05'00'
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 2 of 39 

EXECUTIVE SUMMARY:

The effect of Atrazine on the seedling emergence of monocot corn, Zea mays; onion, Allium cepa; ryegrass, Lolium 

perenne; and oat, Avena sativa) and dicot (cabbage, Brassica oleracea; lettuce, Lactuca sativa; carrot, Daucus 

carota; cucumber, Cucumis sativus; soybean, Glycine max; tomato, Lycopersicon esculentum) crops was studied at a 

nominal concentration of 0 (negative), 0.0050, 0.0098, 0.025, 0.050, 0.098 and 0.25 lb ai/A for cabbage and tomato; 

0 (negative), 0.0098, 0.025, 0.050, 0.098, 0.25 and 0.50 lb ai/A for soybean; 0 (negative), 0.0025, 0.0050, 0.010, 

0.025, 0.050, and 0.098 lb ai/A for cucumber, onion and ryegrass; 0 (negative), 0.0010, 0.0025, 0.0050, 0.010, 

0.025, and 0.050 lb ai/A for carrot, lettuce and oat; 0 (negative), 0.50, 0.98, 2.5, 5.0, 9.8 and 25 lb ai/A for corn. 

Measured application rate were <LOQ (negative), 0.0046/0.0059, 0.0099/0.0082, 0.022/0.021, 0.049/0.047, 

0.097/0.095 and 0.26/0.31 lb ai/A for cabbage and tomato; <LOQ (negative), 0.0082, 0.021, 0.047, 0.095, 0.31 and 

0.44 lb ai/A for soybean; <LOQ (negative), 0.0024, 0.0047, 0.0099, 0.025, 0.047, and 0.10 lb ai/A for cucumber, 

onion and ryegrass; <LOQ (negative), 0.00098/0.0011, 0.0024/0.0042, 0.0046/0.0059, 0.0099/0.0082, 0.022/0.021, 

and 0.049/0.047 lb ai/A for carrot, lettuce and oat; <LOQ (negative), 0.44, 0.95, 2.5, 5.0, 9.9 and 24 lb ai/A for 

corn. LOQ was 0.000065 lb ai/A for cabbage, carrot and lettuce; 0.00016 lb ai/A for onion, ryegrass and cucumber; 

and 0.000067 lb ai/A for corn, oat, soybean and tomato. 

The growth medium used in the seedling emergence test was natural loam soil augmented with washed silica sand 

(pH and organic carbon not reported; 91% sand, 7% silt and 2% clay). For Test 1, on day 14 the surviving plants per 

pot were recorded, and plant height and dry weight were measured. For Test 2, on day 28 the surviving plants per 

pot were recorded, and plant height and dry weight were measured; height data was also reported for day 14 of the 

28 day study. 

Test 1, 14 days 

Based on the reviewer results, negative control emergence was 73-98% compared to the negative control. The 

reviewer found significant inhibition in emergence for cucumber of 15% at 0.047 lb ai/A (Mann-Whitney U TwoSample test, p<0.05). 

The reviewer reported negative control survival, based on number planted, ranged from 73-98% compared to the 

negative control. The reviewer found significant inhibitions in cabbage survival of 47% at 0.26 lb ai/A; in cucumber 

of 26% at 0.047 lb ai/A; and in tomato of 46% at 0.31 lb ai/A compared to the negative control (Mann-Whitney U 

Two-Sample test, p<0.05). 

The reviewer reported dry weight inhibitions for cabbage of 62% at 0.26 lb ai/A, and for tomato of 48 and 78% at 

0.095 and 0.31 lb ai/A (Williams test, p<0.05). There were inhibitions also for oat of 35% at 0.047 lb ai/A 

(Dunnett’s test p<0.05). 

The reviewer reported height inhibitions for cabbage of 19 to 49% at 0.097 and 0.26 lb ai/A (Williams test, p<0.05); 

for oat of 15% at 0.047 lb ai/A (Dunnett’s test, p<0.05); and for tomato of 25 and 53% at 0.095 and 0.31 lb ai/A 

(Jonckheere-Terpstra Step-Down test, p<0.05). 

The most sensitive monocot, based on the reviewer’s results, was oat based on dry weight with NOAEC and EC25

values of 0.021 lb ai/A and 0.0456 lb ai/A, respectively; the most sensitive dicot was cabbage based on dry weight 

with NOAEC and EC25 values of 0.097 and 0.0299 lb ai/A, respectively. 

Based on the phytotoxicity rating system used by the study author, there were no effects in the negative control, and 

no effects for lettuce, oat, onion, and ryegrass at any application rate. There were effects up to 100% for cabbage, 

carrot, corn, cucumber, soybean and tomato. The effects were dose-dependent. 

 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 3 of 39 

Test 2, 28 days 

Based on the reviewer results, negative control emergence was 70-98% compared to the negative control. The 

reviewer found no significant inhibitions in survival for any species at any application rate. 

The reviewer reported negative control survival, based on number planted, ranged from 70-98% compared to the 

negative control. The reviewer found significant inhibitions in cabbage survival of 46 and 85% at 0.097 and 0.26 lb 

ai/A (Dunnett’s test, p<0.05); cucumber of 22% at 0.10 lb ai/A; and in tomato of 46% at 0.31 lb ai/A compared to 

the negative control (Mann-Whitney U Two-Sample test, p<0.05). 

The reviewer reported dry weight inhibitions for cabbage of 35, 45, 34 and 83% at 0.022, 0.049, 0.097, and 0.26 lb 

ai/A; for onion of 35 and 49% at 0.047 and 0.10 lb ai/A (Williams test, p<0.05); and in tomato of 69% at 0.31 lb 

ai/A (Dunnett’s test, p<0.05). 

The reviewer reported height inhibitions for cabbage of 12, 14, 17, 20 and 43% at 0.0099, 0.022, 0.049, 0.097 and 

0.26 lb ai/A; and for onion of 15 and 18% at 0.047 and 0.10 lb ai/A (Williams test, p<0.05). There were also 

inhibitions in height for corn of 28% at 9.9 lb ai/A, cucumber of 11 and 11% at 0.0099 and 0.047 lb ai/A; and 

tomato of 31% at 0.31 lb ai/A (Dunnett’s test, p<0.05).

The most sensitive monocot, based on the reviewer’s results, was onion based on dry weight with NOAEC and EC25

values of 0.025 lb ai/A and 0.0341 lb ai/A, respectively; the most sensitive dicot was cabbage based on dry weight 

with NOAEC and EC25 values of 0.0099 and 0.0177 lb ai/A, respectively. 

Based on the phytotoxicity rating system used by the study author, there were no effects in the negative control, with 

the exception of an individual carrot and corn plant. There were no effects for carrot, lettuce, oat, ryegrass and 

soybean at the application rates. There were effects up to 100% for cabbage, corn, cucumber, onion and tomato. 

The effects were dose-dependent. 

Test 2a, 14 days of 28 day study 

The reviewer was also unable to review survival at 14 days of the 28 day study due to the lack of raw data for 

analysis. 

The reviewer reported height significant inhibitions for cabbage of 28, 34, 42 and 63% at 0.022, 0.049, 0.097 and 

0.26 lb ai/A (Jonckheere-Terpstra Step-Down test, p<0.05). There were also significant inhibitions for corn of 26% 

at 9.9 lb ai/A; for cucumber of 16% at 0.10 lb ai/A; and for tomato of 45% at 0.31 lb ai/A (Dunnett’s test, p<0.05). 

The most sensitive monocot, based on the reviewer’s results, was onion based on height with NOAEC and EC25

values of 0.10 lb ai/A and 0.159 lb ai/A, respectively; the most sensitive dicot was cabbage based on height with 

NOAEC and EC25 values of 0.0099 and 0.0262 lb ai/A, respectively. 

The phytotoxicity on day 14 of the 28 day study was not reported. 

The study author also reported growth rates for height and weight, however the reviewer could not verify these rates. 

Study author results presented in the conclusions at the end of the DER. 

 

Maximum Labeled Rate: 4 lb ai/A (4500 g ai/ha). 

Test 1, 14 days 

Most sensitive monocot: Oat, based on dry weight 

EC50/IC50: 0.0497 lb ai/A 95% C.I.: 0.0488-0.0507 lb ai/A 

EC25/IC25: 0.0456 lb ai/A 95% C.I.: 0.0431-0.0477 lb ai/A 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 4 of 39 

EC05/IC05: 0.0403 lb ai/A 95% C.I.: N/A-0.043 lb ai/A 

NOEC: 0.021 lb ai/A 

Slope: N/A 95% C.I.: N/A 

 

Most sensitive dicot: Cabbage, based on dry weight 

EC50/IC50: 0.132 lb ai/A 95% C.I.: 0.063-0.277 lb ai/A 

EC25/IC25: 0.0299 lb ai/A 95% C.I.: 0.00884-0.0713 lb ai/A 

EC05/IC05: 0.00351 lb ai/A 95% C.I.: N/A-0.0215 lb ai/A 

NOEC: 0.097 lb ai/A 

Slope: N/A 95% C.I.: N/A 

Test 2, 28 days 

Most sensitive monocot: Onion, based on dry weight 

EC50/IC50: 0.144 lb ai/A 95% C.I.: 0.050-0.413 lb ai/A 

EC25/IC25: 0.0341 lb ai/A 95% C.I.: 0.0153-0.0645 lb ai/A 

EC05/IC05: 0.00432 lb ai/A 95% C.I.: N/A-0.016 lb ai/A 

NOEC: 0.025 lb ai/A 

Slope: N/A 95% C.I.: N/A 

Most sensitive dicot: Cabbage, based on dry weight 

EC50/IC50: 0.102 lb ai/A 95% C.I.: 0.0496-0.21 lb ai/A 

EC25/IC25: 0.0177 lb ai/A 95% C.I.: 0.00657-0.0389 lb ai/A 

EC05/IC05: 0.00143 lb ai/A 95% C.I.: N/A-0.01 lb ai/A 

NOEC: 0.0099 lb ai/A 

Slope: N/A 95% C.I.: N/A 

Test 2a, 14 days of 28 days 

Most sensitive monocot: Onion, based on height (only endpoint analyzed) 

EC50/IC50: NC 95% C.I.: N/A 

EC25/IC25: 0.159 lb ai/A 95% C.I.: 0.00491-0.625 lb ai/A 

EC05/IC05: 0.0205 lb ai/A 95% C.I.: N/A-0.0693 lb ai/A 

NOEC: 0.10 lb ai/A 

Slope: N/A 95% C.I.: N/A 

Most sensitive dicot: Cabbage, based on height (only endpoint analyzed) 

EC50/IC50: 0.132 lb ai/A 95% C.I.: 0.0872-0.199 lb ai/A 

EC25/IC25: 0.0262 lb ai/A 95% C.I.: 0.0158-0.0409 lb ai/A 

EC05/IC05: 0.00257 lb ai/A 95% C.I.: N/A-0.00834 lb ai/A 

NOEC: 0.0099 lb ai/A 

Slope: N/A 95% C.I.: N/A 

This toxicity study is classified as acceptable for the herein labeled “Test 1-14-day Study”. The concurrent 28-day 

study labeled here as Test 2 and Test 2a is classified as supplemental, as the study design did not allow for dry 

weight endpoints at the 14-day period, did not provide survival at 14-days. 

Table 1a. Summary of most sensitive parameters by species (lb ai/A); Test 1, 14 days 

Species Endpoint NOEC EC05/IC05 EC25/IC25 EC50/IC50
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 5 of 39 

Cabbage Dry weight 0.097 0.00351 0.0299 0.132 

Carrot None 0.049 NC NC NC 

Corn* Dry weight 24 9.6 >24 NC 

Cucumber None 0.10 >0.10 >0.10 >0.10 

Lettuce None 0.049 >0.049 >0.049 >0.049 

Oat Dry weight 0.021 0.0403 0.0456 0.0497 

Onion None 0.10 >0.10 >0.10 >0.10 

Ryegrass None 0.10 >0.10 >0.10 >0.10 

Soybean* Dry weight 0.44 0.316 >0.44 >0.44 

Tomato Dry weight 0.047 0.0168 0.0527 0.117 

* Not a dose response and/or ECx/ICx values are not bracketed by the test concentrations and are unreliable. 

Table 1b. Summary of most sensitive parameters by species (lb ai/A); Test 2, 28 days 

Species Endpoint NOEC EC05/IC05 EC25/IC25 EC50/IC50

Cabbage Dry weight 0.0099 0.00143 0.0177 0.102 

Carrot None 0.049 >0.049 >0.049 >0.049 

Corn* Height 5.0 1.31 >24 NC 

Cucumber* Height 0.0047 0.00376 >0.10 NC 

Lettuce Dry weight 0.049 0.0222 0.0475 0.0804 

Oat None 0.047 >0.047 >0.047 >0.047 

Onion Dry weight 0.025 0.00432 0.0341 0.144 

Ryegrass* Dry weight 0.10 0.0285 >0.10 NC 

Soybean* Dry weight 0.44 0.0493 >0.44 NC 

Tomato Dry weight 0.095 0.0776 0.146 0.225 

* Not a dose response and/or ECx/ICx values are not bracketed by the test concentrations and are unreliable. 

Table 1c. Summary of most sensitive parameters by species (lb ai/A); Test 2a, 14 days of 28 days (height only 

endpoint analyzed) 

Species Endpoint NOEC EC05/IC05 EC25/IC25 EC50/IC50

Cabbage Height 0.0099 0.00257 0.0262 0.132 

Carrot None 0.049 >0.049 >0.049 >0.049

Corn* Height 5.0 1.5 34.6 307 

Cucumber* Height 0.047 0.0365 0.23 NC 

Lettuce* Height 0.049 0.0307 0.0645 NC 

Oat None 0.047 >0.047 >0.047 >0.047

Onion* Height 0.10 0.0205 0.159 NC 

Ryegrass None 0.10 >0.10 >0.10 >0.10 

Soybean None 0.44 >0.44 >0.44 >0.44 

Tomato Height 0.095 0.049 0.164 >0.31 

* Not a dose response and/or ECx/ICx values are not bracketed by the test concentrations and are unreliable. 

 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 6 of 39 

I. MATERIALS AND METHODS

GUIDELINE FOLLOWED: This study was conducted in compliance with OPPTS 850.4100: 

Seedling Emergence (January 2012) and OECD Guideline No. 208: 

Terrestrial Plant Test: Seedling Emergence test. The reviewer evaluated 

the study methods according to EPA Ecological Effects Test 

Guidelines, OCSPP Guideline 850.4100: Seedling Emergence. There 

were some deficiency and deviations noted by the reviewer. 

1. The physico-chemical properties of the test material were not reported. 

2. Survival at 14 days in the 28 day study was not analyzed by the study author, and raw 

data were not provided. The reviewer could not perform statistical analysis or report 

results for this endpoint. 

 The deficiency and deviations did have an impact on the acceptability of this study. 

COMPLIANCE: Signed and dated GLP, Quality Assurance and No Data Confidentiality 

statements were provided. This study was conducted in compliance with 

USEPA (40 CFR, Part 160) and OECD (OECD, 1998) Principles of Good 

Laboratory Practice., with the following exception: routine water and food 

contaminant screening analyses for PCBs, pesticides and toxic metals were 

conducted using standard U.S. EPA procedures by GeoLabs, Inc, Braintree, 

Massachusetts and are considered facility records under Smithers Viscient’s 

Standard Operating Procedures. Since the analyses were conducted 

following standard validated methods, these exceptions had no impact on 

the study results. 

A. MATERIALS:

 1. Test Material Atrazine SC

Description: White liquid.

Lot No./Batch No.: 726537 

Purity: 43.0% (w/w) 

Stability of compound 

under test conditions: Analytical determinations based on measured concentration of the test 

material in the spray solution yielded a recoveries of 85.0-117.2% of 

nominal; with the exception of the 0.0042 lb ai/A test concentrations for 

corn, oat, soybean and tomato, which was 170.0% of nominal. Stability 

was not determined. QC recoveries ranged from 64-119%. Method 

recoveries of the atrazine from 1% crop oil in deionized water were 

104±7.97% (n=9). 

 (OECD recommends chemical stability in water and light) 

Storage conditions of 

test chemicals: The test material was stored in the dark at room temperature. 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 7 of 39 

 Table 2. Physical/chemical properties of Atrazine 

Parameter Values Comments

Water solubility at 20 ̊C Not reported

Vapor pressure Not reported

UV absorption Not reported

pKa Not reported

Kow Not reported

 2. Test organism: 

Monocotyledonous species: Corn (Zea mays, Golden Bantam); Onion (Allium cepa, Yellow Granex); 

Ryegrass (Lolium perenne, Linn) and Oat (Avena sativa, Swan); EPA recommends four monocots in two 

families, including corn. 

Dicotyledonous species: Lettuce (Lactuca sativa, Prizehead); Cabbage, Brassica oleracea, Ganzales); 

Carrot (Daucus carota, Imperator 58); Cucumber (Cucumis sativus, Bush Champion); Tomato 

(Lycopersicon esculentum, Celebrity Hybrid); and Soybean (Glycine max, Envy); EPA recommends six 

dicots in four families, including soybean and a root crop. 

OECD recommends a minimum of three species selected for testing, at least one from each of the following categories: 

Category 1: ryegrass, rice, oat, wheat, and sorghum; Category 2: mustard, rape, radish, turnip, and Chinese cabbage; 

Category 3: vetch, mung bean, red clover, fenugreek, lettuce, and cress.

Seed source: Cabbage, onion from Park Seed Company; carrot and lettuce from Sustainable Seed 

Company; corn, cucumber from Burpee; oat from L.A. Hearne Compound; ryegrass from Granite Seed, 

soybean from Johnny’s Selected Seeds; and tomato from Tomato Growers Supply Company. 

Prior seed treatment/sterilization: The seeds were not treated with any type of fungicides, insecticides, or 

any pesticides. 

Historical % germination of seed: Carrot, 83%; lettuce, 85%; oat, 90%; ryegrass, 95%; soybean, 87%; 

cabbage, corn, cucumber, onion and tomato, N/A. 

 Seed storage, if any: Seeds stored refrigerated in the dark until use. 

B. STUDY DESIGN:

1. Experimental Conditions 

a. Limit test: None. 

b. Range-finding study: 

c. Definitive Study 

Table 3: Experimental Parameters – Seedling Emergence.
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 8 of 39 

Parameters Seedling Emergence 

Details Remarks 

Criteria 

Duration of the test Test 1: 14 days 

Test 2: 28 days Recommended test duration is 14-21 days. 

OECD recommends that the test be terminated no 

sooner than 14 days after 50 percent of the control 

seedlings have emerged

Number of 

seeds/plants/species/ 

replicate

Oat, onion and ryegrass, 5 

replicates with 8 plants per 

replicate; 

All others 10 replicates with 4 

plants per replicates. 

Ten seeds per replicate should be used. 

OECD recommends a minimum of five seeds planted 

in each replicate within 24 hours of incorporation of 

the test substance. All seeds of each species for each 

test should be of the same size class. The seed 

should not be imbibed.

Number of replicates 

Control:

Adjuvant control:

Treated:

Control:

Adjuvant control: 

Treated:

Oat, onion and ryegrass: 

5 

N/A

5 

All others:

10

N/A

10

Four replicates per dose should be used. 

OECD recommends a minimum of four replicates 

per treatment
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 9 of 39 

Parameters Seedling Emergence 

Details Remarks 

Criteria 

Test concentrations (lb 

ai/A)

Nominal:

Measured: 

0 (negative), 0.0050, 0.0098, 

0.025, 0.050, 0.098 and 0.25 lb 

ai/A for cabbage and tomato; 

0 (negative), 0.0098, 0.025, 0.050, 

0.098, 0.25 and 0.50 lb ai/A for 

soybean; 

0 (negative), 0.0025, 0.0050, 

0.010, 0.025, 0.050, and 0.098 lb 

ai/A for cucumber, onion and 

ryegrass; 

0 (negative), 0.0010, 0.0025, 

0.0050, 0.010, 0.025, and 0.050 lb 

ai/A for carrot, lettuce and oat; 

0 (negative), 0.50, 0.98, 2.5, 5.0, 

9.8 and 25 lb ai/A for corn. 

 

<LOQ (negative), 0.0046/0.0059, 

0.0099/0.0082, 0.022/0.021, 

0.049/0.047, 0.097/0.095 and 

0.26/0.31 lb ai/A for cabbage and 

tomato;

<LOQ (negative), 0.0082, 0.021, 

0.047, 0.095, 0.31 and 0.44 lb 

ai/A for soybean; 

<LOQ (negative), 0.0024, 0.0047, 

0.0099, 0.025, 0.047, and 0.10 lb 

ai/A for cucumber, onion and 

ryegrass; 

<LOQ (negative), 

0.00098/0.0011, 0.0024/0.0042, 

0.0046/0.0059, 0.0099/0.0082, 

0.022/0.021, and 0.049/0.047 lb 

ai/A for carrot, lettuce and oat; 

<LOQ (negative), 0.44, 0.95, 2.5, 

5.0, 9.9 and 24 lb ai/A for corn. 

LOQ = 0.000065 lb ai/A for cabbage, carrot 

and lettuce; 

LOQ = 0.00016 lb ai/A for onion, ryegrass and 

cucumber; 

LOQ = 0.000067 lb ai/A for corn, oat, soybean 

and tomato. 

Five test concentrations should be used with a dose 

range of 2X or 3X progression

OECD recommends three concentrations, preferably 

with application rates equivalent to 0.0 (control), 

1.0, 10.0 and 100 mg substance per kg of oven-dried 

soil.

Method and interval of

analytical verification

Samples were taken from the 

negative control and the treatment 

groups for analysis via HPLC 

with UV detection: Aglient 

Zorbax SB-C18 column and 224 

nm wavelength
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 10 of 39 

Parameters Seedling Emergence 

Details Remarks 

Criteria 

LOQ: 

LOD:

0.000065 lb ai/A for cabbage, 

carrot and lettuce; 

0.00016 lb ai/A for onion, 

ryegrass and cucumber; 

0.000067 lb ai/A for corn, oat, 

soybean and tomato. 

N/A

Adjuvant (type, percentage, 

if used)

Crop oil (AGri-Dex), 1% 

Test container (pot) 

Size/Volume

Material: 

(glass/polystyrene)

13 cm tall and 26 cm top diameter 

(20 cm bottom diameter); 20 cm 

fill paper interior base. 

Polypropylene

Non-porous containers should be used. 

OECD recommends that non-porous plastic or 

glazed pot be used.

Growth facility Greenhouse 

Method/depth of seeding Seeds were placed in a circular 

pattern around the inside 

perimeter of the pot. 

Test material application 

Application time including 

the plant growth stage

Number of application 

Application interval 

Method of application

1 

N/A- single application 

The test material was applied 

using a conventional agricultural 

overhead atomizing spray nozzle 

(8001-E-SS) and revolving belt. 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 11 of 39 

Parameters Seedling Emergence 

Details Remarks 

Criteria 

Details of soil used

Geographic location

Depth of soil collection

Soil texture

% sand 

% silt 

% clay 

pH:

% organic carbon

CEC (meq/100 g) 

Moisture at 1/3 atm (%) 

N/A

N/A

Sand

91

7 

2 

Not reported

Not reported

Not reported

Not reported

Not reported

Natural loam soil combined with washed silica 

sand. 

Soil mixes containing sandy loam, loam, or clay 

loam soil with no greater than 2% organic matter 

are preferable. Glass beads, rock wool, and 100% 

acid washed sand are not preferred.

OECD prefers the soil to be sieved (0.5 cm) to 

remove coarse fragments. Carbon content should 

not exceed 1.5% (3% organic matter). Fine particles 

(under 20um) makeup should be between 10 and 

20%. The recommended pH is between 5.0 and 7.5.

Details of nutrient medium, 

if used

Peters 20-20-20 (N-P-K), 400 

mg/L for corn, oat, soybean and 

tomato. Applied (100 mL) by 

sub-irrigation twice weekly. 

Watering regime and 

schedules

Water source/type:

Volume applied:

Interval of application:

Method of application:

Well water (Town of Wareham). 

Not reported.

Daily. 

The plants were bottom watered 

after being initially top watered 

(100 mL deionized water) to 

promote capillary action. 

EPA prefers that bottom watering be utilized for 

seedling emergence studies so that the chemical is 

not leached out of the soil during the test.

Any pest control 

method/fertilization, if used 

None reported 

Test conditions

Temperature:

Photoperiod:

Light intensity and quality: 

Relative humidity:

15-51 ̊C

16L:8D

Natural sunlight supplemented 

with artificial light. 

69-1500 μmol/m2/sec 

15-98% 

EPA prefers that the cold vs warm loving plants be 

tested in two separate groups to optimize plant 

growth.

OECD prefers that the temperature, humidity and 

light conditions be suitable for maintaining normal 

growth of each species for the test period.
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Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

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Parameters Seedling Emergence 

Details Remarks 

Criteria 

Reference chemical (if 

used)

Name:

Concentrations: 

N/A

Other parameters, if any None 

 

2. Observations: 

Table 4: Observation Parameters – Seedling Emergence.

Parameters Seedling Emergence 

Details Remarks 

Parameters measured (e.g., number 

of germinated seeds, emerged 

seedlings, plant height, dry weight 

or other endpoints)

- Emergence 

- Survival 

- Height

- Mean dry weight 

- Phytotoxicity

Measurement technique for each 

parameter 

Phytotoxicity was visually 

determined. Height was 

measured to the nearest 

0.5 centimeter from the 

soil surface to the tallest 

new growth. Mean plant 

weight was estimated by 

measuring the dry weight 

following drying at 70 ± 5 

 ̊C. 

Observation intervals Each pot was inspected 

weekly and phytotoxicity 

assessments performed. 

Plant height and dry 

weight were recorded at 

study termination. 

Other observations, if any N/A 

Were raw data included? Yes 

The health rating, 
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Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 13 of 39 

Phytotoxicity rating system, if used including morphological 

abnormalities ranges from 

0 to 100, where 0 

indicates no injury or 

abnormality and 100 

indicates complete effect 

(dead plant). 

II. RESULTS and DISCUSSION:

A. INHIBITORY EFFECTS:

1. Seedling Emergence: 

Test 1, 14 days 

Based on the study author and reviewer results, negative control emergence was 73-98% compared to the 

negative control. The study author did not find any significant inhibitions in emergence for any species at 

any application rate. The reviewer found significant inhibition in emergence for cucumber of 15% at 0.047 

lb ai/A (Mann-Whitney U Two-Sample test, p<0.05). 

The study author reported negative control survival, based the number emerged, was 100% compared to the 

negative control. The study author found survival significant inhibitions in cabbage of 20, 20 and 53% at 

0.050, 0.098 and 0.25 lb ai/A; and in tomato of 42% at 0.25 lb ai/A (Fisher’s Exact Test with BonferroniHolm’s Adjustment, p<0.05). The reviewer reported negative control survival, based on number planted, 

ranged from 73-98% compared to the negative control. The reviewer found significant inhibitions in 

cabbage survival of 47% at 0.26 lb ai/A; in cucumber of 26% at 0.047 lb ai/A; and in tomato of 46% at 0.31 

lb ai/A compared to the negative control (Mann-Whitney U Two-Sample test, p<0.05). 

The study author found significant inhibitions in dry weight compared to the negative control for cabbage 

of 62% at 0.25 lb ai/A; for oat of 35% at 0.050 lb ai/A; and in tomato of 48 and 78% at 0.098 and 0.25 lb 

ai/A, respectively (Dunnett’s Multiple Comparison test, p<0.05). The reviewer reported similar results, 

with dry weight significant inhibitions for cabbage of 62% at 0.26 lb ai/A, and for tomato of 48 and 78% at 

0.095 and 0.31 lb ai/A, respectively (Williams test, p<0.05). There were also significant inhibitions for oat 

of 35% at 0.047 lb ai/A (Dunnett’s test p<0.05). 

The study author found significant inhibitions in height for cabbage of 49% at 0.25 lb ai/A, and oat of 15% 

at 0.050 lb ai/A compared to the negative control (Dunnett’s Multiple Comparison test, p<0.05). There 

were inhibitions in tomato height of 25 and 53% at 0.098 and 0.25 lb ai/A (Wilcoxon’s Test with 

Bonferroni-Holm’s Adjustment, p<0.05). The reviewer reported similar results, with height significant 

inhibitions for cabbage of 19 and 49% at 0.097 and 0.26 lb ai/A, respectively (Williams test, p<0.05); for 

oat of 15% at 0.047 lb ai/A (Dunnett’s test, p<0.05); and for tomato of 25 and 53% at 0.095 and 0.31 lb 

ai/A, respectively (Jonckheere-Terpstra Step-Down test, p<0.05). 

The most sensitive monocot, based on the study author's results, was oat based on dry weight with NOAEC 

and EC25 values of 0.025 lb ai/A and 0.039 lb ai/A, respectively; the most sensitive dicot was cabbage 

based on dry weight with NOAEC and EC25 values of 0.098 and 0.010 lb ai/A, respectively. 

The most sensitive monocot, based on the reviewer’s results, was oat based on dry weight with NOAEC 

and EC25 values of 0.021 lb ai/A and 0.0456 lb ai/A, respectively; the most sensitive dicot was cabbage 

based on dry weight with NOAEC and EC25 values of 0.097 and 0.0299 lb ai/A, respectively. 
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Based on the phytotoxicity rating system used by the study author, there were no effects in the negative 

control, and no effects for lettuce, oat, onion, and ryegrass at any application rate. There were effects up to 

100% for cabbage, carrot, corn, cucumber, soybean and tomato. The effects were dose-dependent. 

 

Test 2, 28 days 

Based on the study author and reviewer results, negative control emergence was 70-98% compared to the 

negative control. The study author and reviewer found no significant inhibitions in emergence for any 

species at any application rate. 

The study author reported negative control survival, based the number emerged, was 98-100%, compared 

to the negative control. The study author found survival significant inhibitions in cabbage of 46 and 85% at 

0.098 and 0.25 lb ai/A; and in tomato of 48% at 0.25 lb ai/A (Fisher’s Exact Test with Bonferroni-Holm’s 

Adjustment, p<0.05). The reviewer reported negative control survival, based on number planted, ranged 

from 70-98% compared to the negative control. The reviewer found significant inhibitions in cabbage 

survival of 46 and 85% at 0.097 and 0.26 lb ai/A, respectively (Dunnett’s test, p<0.05); cucumber of 22% 

at 0.10 lb ai/A; and in tomato of 46% at 0.31 lb ai/A compared to the negative control (Mann-Whitney U 

Two-Sample test, p<0.05). 

The study author found significant inhibitions in dry weight for cabbage of 35, 45, 34 and 83% at 0.025, 

0.050, 0.098 and 0.25 lb ai/A, respectively; for onion of 35 and 49% at 0.050 and 0.098 lb ai/A, 

respectively; and in tomato of 69% at 0.25 lb ai/A (Dunnett’s Multiple Comparison test, p<0.05). The 

reviewer reported similar results, with dry weight significant inhibitions for cabbage of 35, 45, 34 and 83% 

at 0.022, 0.049, 0.097, and 0.26 lb ai/A, respectively; onion of 35 and 49% at 0.047 and 0.10 lb ai/A, 

respectively (Williams test, p<0.05); and tomato of 69% at 0.31 lb ai/A (Dunnett’s test, p<0.05). 

The study author found significant inhibitions in height for cabbage of 17, 20 and 43% at 0.050, 0.098 and 

0.25 lb ai/A, respectively; corn of 28% at 9.8 lb ai/A; cucumber of 11 and 11% at 0.010 and 0.050 lb ai/A, 

respectively; and onion of 18% at 0.098 lb ai/A (Dunnett’s Multiple Comparison test, p<0.05). There were 

also significant inhibitions in tomato height of 31% at 0.25 lb ai/A (Wilcoxon’s Test with BonferroniHolm’s Adjustment, p<0.05). The reviewer reported similar results, with significant height inhibitions for 

cabbage of 12, 14, 17, 20 and 43% at 0.0099, 0.022, 0.049, 0.097 and 0.26 lb ai/A, respectively; and for 

onion of 15 and 18% at 0.047 and 0.10 lb ai/A, respectively (Williams test, p<0.05). There were also 

significant inhibitions in height for corn of 28% at 9.9 lb ai/A, cucumber of 11 and 11% at 0.0099 and 

0.047 lb ai/A, respectively; and tomato of 31% at 0.31 lb ai/A (Dunnett’s test, p<0.05). 

The most sensitive monocot, based on the study author's results, was onion based on dry weight with 

NOAEC and EC25 values of 0.025 lb ai/A and 0.031 lb ai/A, respectively; the most sensitive dicot was 

cabbage based on dry weight with NOAEC and EC25 values of 0.010 and 0.014 lb ai/A, respectively. 

The most sensitive monocot, based on the reviewer’s results, was onion based on dry weight with NOAEC 

and EC25 values of 0.025 lb ai/A and 0.0341 lb ai/A, respectively; the most sensitive dicot was cabbage 

based on dry weight with NOAEC and EC25 values of 0.0099 and 0.0177 lb ai/A, respectively. 

Based on the phytotoxicity rating system used by the study author, there were no effects in the negative 

control, with the exception of an individual carrot and corn plant. There were no effects for carrot, lettuce, 

oat, ryegrass and soybean at the application rates. There were effects up to 100% for cabbage, corn, 

cucumber, onion and tomato. The effects were dose-dependent. 

Test 2a, 14 days of 28 day study 

Using the study author results for the full 28 day study, survival in the negative control, based on number 

emerged was 98-100%. Raw data and percent inhibitions for survival at 14 days of the 28 day study was 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

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not provided, and the study author did not report the results of any statistical analysis (NOEC and ECx). 

The reviewer was also unable to review survival at 14 days of the 28 day study due to the lack of raw data 

for analysis. 

The study author did not report the results of any statistical analysis or inhibitions in height for any species 

at 14 days of the 28 day study. The reviewer reported significant height inhibitions for cabbage of 28, 34, 

42 and 63% at 0.022, 0.049, 0.097 and 0.26 lb ai/A, respectively (Jonckheere-Terpstra Step-Down test, 

p<0.05). There were also significant inhibitions for corn of 26% at 9.9 lb ai/A; cucumber of 16% at 0.10 lb 

ai/A; and tomato of 45% at 0.31 lb ai/A (Dunnett’s test, p<0.05). 

The most sensitive monocot and dicot could not be determined for the study author because the data were 

not analyzed. 

The most sensitive monocot, based on the reviewer’s results, was onion based on height with NOAEC and 

EC25 values of 0.10 lb ai/A and 0.159 lb ai/A, respectively; the most sensitive dicot was cabbage based on 

height with NOAEC and EC25 values of 0.0099 and 0.0262 lb ai/A, respectively. 

The phytotoxicity on day 14 of the 28 day study was not reported. 

B. REPORTED STATISTICS: 

Emergence, survival, dry weight, and height means and standard deviations were determined for control and 

treatment groups. For Test 1, the average specific growth rate was calculated for shoot length between test 

initiation and day 14 and shoot dry weight between test initiation and day 28 (test termination). For Test 2, the 

average specific growth rate for shoot length was calculated from test initiation to day 14, day 14 to day 28, and 

test termination. The average specific growth rate for shoot dry weight was calculated using the Test 1 shoot dry 

weight data from day 14 and Test 2 shoot dry weight at test termination. 

The No-Observed-Effect Concentration (NOEC), the highest test concentration which demonstrated no 

statistically adverse effect (p < 0.05) on day 14 (Test 1) and day 28 (Test 2) percent emergence, survival, shoot 

length, shoot dry weight and average growth rate based on shoot length and shoot dry weight when compared to 

the control data was determined. Fisher's Exact Test was used to establish treatment effects for percent survival 

data. The data were first checked for normality and homogeneity of variance using Shapiro-Wilk's and Bartlett's 

Test. If the data sets passed the tests for homogeneity and normality, then the appropriate parametric procedure 

(i.e. Dunnett's Multiple Comparison Test) was used to determine the NOEC. If the data did not pass the tests for 

homogeneity and normality, then a non-parametric procedure (i.e., Wilcoxon's Test with Bonferroni-Holm's 

Adjustment) was used to determine the NOEC. All statistical determinations were made at the 95% level of 

certainty, except in the case of Shapiro-Wilks' Test and Bartlett's Test, where the 99% level of certainty was 

applied. At termination of the tests, the treatment data (percent survival, shoot length, shoot dry weight and 

average growth rate for shoot length and dry weight) were expressed as percent inhibition relative to the control. 

The ECx values and 95% confidence limits were determined by linear interpolation of response as compared 

with the control vs. nominal application rate. The regressions were limited to the concentration range for which 

a clear exposure-response relationship was observed. If less than the designated percent inhibition was observed 

for a biological endpoint, the EC values were empirically estimated to be greater than the highest application 

rate tested. 

Nominal concentrations were used. 

 
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Seedling Emergence

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Table 5: Effect of Atrazine on 14-Day Seedling Emergence (Test 1)

Species Results summary for biomass (lbs ai/A) 

weight (g) NOEC* IC10 95%CI IC25 95%CI IC50 95%CI slope 95%CI 

Cabbage1 0.0144-0.0478 0.098 0.0066 0.0018-

0.016 

0.010 0.0070-

0.107 

0.143 0.024-ND N/A N/A 

Carrot 0.0337-0.0414 0.050 >0.050 ND >0.050 ND >0.050 ND N/A N/A 

Corn 0.172-0.262 25 8.9 0.4-ND >25 ND >25 ND N/A N/A 

Cucumber 0.297-0.398 0.098 >0.098 ND >0.098 ND >0.098 ND N/A N/A 

Lettuce 0.0339-0.0699 0.050 >0.050 ND >0.050 ND >0.050 ND N/A N/A 

Oat2 0.0727-0.114 0.025 0.028 ND-0.036 0.039 0.027-ND >0.050 ND N/A N/A 

Onion 0.00658-0.00978 0.098 >0.098 ND >0.098 ND >0.098 ND N/A N/A 

Ryegrass 0.0198-0.0262 0.098 >0.098 ND >0.098 ND >0.098 ND N/A N/A 

Soybean 0.322-0.541 0.50 0.072 0.062-

0.152 

>0.50 ND >0.50 ND N/A N/A 

Tomato3 0.0265-0.124 0.050 0.032 0.0015-

0.052 

0.054 0.027-

0.070 

0.107 0.071-

0.134 

N/A N/A 

ND- Not determined. NC- Not calculable. 

*NOEC and all significant inhibitions determined by Dunnett’s Multiple Comparison Test (p<0.05), unless specified otherwise.

1 Significant decrease in cabbage weight, inhibition of 62% at the 0.25 lb ai/A. 

2 Significant decrease in oat weight, inhibition of 35% at the 0.050 lb ai/A. 

3 Significant decrease in tomato weight, inhibitions of 48 and 78% at 0.098 and 0.25 lb ai/A. 

 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

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Table 5a: Effect of Atrazine on 14-Day Seedling Emergence (Test 1)

Species Results summary for height (lbs ai/A) 

height 

(cm)

NOEC* IC10 95%CI IC25 95%CI IC50 95%CI slope 95%CI 

Cabbage1 2.24-4.77 0.098 0.014 0.0061-

0.037 

0.107 0.021-

0.134 

0.241 0.169-ND N/A N/A 

Carrot 9.74-10.5 0.050 >0.050 ND >0.050 ND >0.050 ND N/A N/A 

Corn 36.7-44.6 25 15.2 5.3-ND >25 ND >25 ND N/A N/A 

Cucumber 18.5-27.6 0.098 >0.098 ND >0.098 ND >0.098 ND N/A N/A 

Lettuce 3.46-5.57 0.050 >0.050 ND >0.050 ND >0.050 ND N/A N/A 

Oat2 29.9-36.4 0.025 0.037 0.010-ND >0.050 ND >0.050 ND N/A N/A 

Onion 11.4-16.2 0.098 >0.098 ND >0.098 ND >0.098 ND N/A N/A 

Ryegrass 22.6-24.7 0.098 >0.098 ND >0.098 ND >0.098 ND N/A N/A 

Soybean 31.5-43.1 0.50 >0.50 ND >0.50 ND >0.50 ND N/A N/A 

Tomato3 11.5-25.4 0.050 0.051 0.0049-

0.065 

0.098 0.072-

0.125 

0.223 0.187-ND N/A N/A 

ND- Not determined. NC- Not calculable. 

*NOEC and all significant inhibitions determined by Dunnett’s Multiple Comparison Test (p<0.05), unless specified otherwise.

1 Significant decrease in cabbage height, inhibition of 49% at 0.25 lb ai/A. 

2 Significant decrease in oat height, inhibition of 15% at 0.050 lb ai/A. 

3 Significant decrease in tomato height, inhibitions of 25 and 53% at 0.098 and 0.25 lb ai/A (Wilcoxon’s Test with Bonferroni-Holm’s 

Adjustment, p<0.05). 

 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

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Table 5b: Effect of Atrazine on 14-Day Seedling Emergence (Test 1)

Species Results summary for emergence (lbs ai/A) 

% NOEC EC10 95%CI EC25 95%CI EC50 95%CI slope 95%CI 

Cabbage 85-98 0.25 >0.25 ND >0.25 ND >0.25 ND N/A N/A 

Carrot 75-93 0.050 >0.050 ND >0.050 ND >0.050 ND N/A N/A 

Corn 85-93 25 >25 ND >25 ND >25 ND N/A N/A 

Cucumber 83-100 0.098 >0.098 ND >0.098 ND >0.098 ND N/A N/A 

Lettuce 70-90 0.050 >0.050 ND >0.050 ND >0.050 ND N/A N/A 

Oat 78-98 0.050 0.031 ND >0.050 ND >0.050 ND N/A N/A 

Onion 70-85 0.098 >0.098 ND >0.098 ND >0.098 ND N/A N/A 

Ryegrass 83-93 0.098 >0.098 ND >0.098 ND >0.098 ND N/A N/A 

Soybean 60-75 0.50 >0.50 ND >0.50 ND >0.50 ND N/A N/A 

Tomato 80-93 0.25 >0.25 ND >0.25 ND >0.25 ND N/A N/A 

ND- Not determined. NC- Not calculable. 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

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Table 5c: Effect of Atrazine on 14-Day Seedling Emergence (Test 1)

Species Results summary for survival, based on # emerged (lbs ai/A) 

% NOEC* EC10 95%CI EC25 95%CI EC50 95%CI slope 95%CI 

Cabbage1 48-100 0.25 0.031 0.021-

0.098 

0.116 0.043-

0.143 

0.232 0.161-ND N/A N/A 

Carrot 97-100 0.050 >0.050 ND >0.050 ND >0.050 ND N/A N/A 

Corn 98-100 25 >25 ND >25 ND >25 ND N/A N/A 

Cucumber 85-100 0.098 0.046 0.033-ND >0.098 ND >0.098 ND N/A N/A 

Lettuce 100 0.050 >0.050 ND >0.050 ND >0.050 ND N/A N/A 

Oat 100 0.050 0.051 ND >0.050 ND >0.050 ND N/A N/A 

Onion 97-100 0.098 >0.098 ND >0.098 ND >0.098 ND N/A N/A 

Ryegrass 100 0.098 >0.098 ND >0.098 ND >0.098 ND N/A N/A 

Soybean 95-100 0.50 >0.50 ND >0.50 ND >0.50 ND N/A N/A 

Tomato2 58-100 0.098 0.116 0.098-

0.134 

0.161 0.134-

0.232 

0.25 ND N/A N/A 

ND- Not determined. NC- Not calculable. 

*NOEC and all significant inhibitions determined by Fisher’s Exact Test with Bonferroni-Holm’s Adjustment (p<0.05).

1 Significant decrease in cabbage survival, inhibition of 20, 20 and 53% at 0.050, 0.098 and 0.25 lb ai/A. 

2 Significant decrease in tomato survival, inhibition of 42% at 0.25 lb ai/A. 

Plant Injury Index*; Test 1

Control Cabbage Carrot Corn Cucumber Lettuce Oat Onion Ryegrass Soybean Tomato Formulation 

Blank

0 0-100 0-100 0-100 0-100 0 0 0 0 0-100 0-100 N/A 

* The health rating, including morphological abnormalities ranges from 0 to 100, where 0 indicates no injury or abnormality and 100 indicates 

complete effect (dead plant). 

 
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Seedling Emergence

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Table 6: Effect of Atrazine on 28-Day Seedling Emergence (Test 2)

Species Results summary for biomass (lbs ai/A) 

weight (g) NOEC* IC10 95%CI IC25 95%CI IC50 95%CI slope 95%CI 

Cabbage1 0.161-0.925 0.010 0.0054 0.0010-

0.014 

0.014 0.0046-

0.098 

0.125 0.024-

0.152 

N/A N/A 

Carrot 0.454-0.633 0.050 >0.050 ND >0.050 ND >0.050 ND N/A N/A 

Corn 0.799-1.6 25 5.8 0.11-6.7 7.7 2.3-18.7 >25 ND N/A N/A 

Cucumber 1.8-2.29 0.098 >0.098 ND >0.098 ND >0.098 ND N/A N/A 

Lettuce 0.755-1.14 0.050 0.029 0.013-

0.037 

>0.050 ND >0.050 ND N/A N/A 

Oat 0.458-0.592 0.050 >0.050 ND >0.050 ND >0.050 ND N/A N/A 

Onion2 0.0285-0.0557 0.025 0.0015 ND-0.045 0.031 ND-0.080 >0.098 ND N/A N/A 

Ryegrass 0.187-0.225 0.098 0.037 ND-0.107 >0.098 ND >0.098 ND N/A N/A 

Soybean 0.938-1.43 0.50 0.107 0.129-ND >0.50 ND >0.50 ND N/A N/A 

Tomato3 0.426-1.46 0.098 0.088 0.0024-

0.116 

0.125 0.073-

0.143 

0.187 0.152-

0.223 

N/A N/A 

ND- Not determined. NC- Not calculable. 

*NOEC and all significant inhibitions determined by Dunnett’s Multiple Comparison Test (p<0.05), unless specified otherwise.

1 Significant decrease in cabbage weight, inhibition of 35, 45, 34 and 83% at 0.025, 0.050, 0.098 and 0.25 lb ai/A. 

2 Significant decrease in onion weight, inhibition of 35 and 49% at the 0.050 and 0.098 lb ai/A. 

3 Significant decrease in tomato weight, inhibitions of 69% at 0.25 lb ai/A. 

 
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Table 6a: Effect of Atrazine on 28-Day Seedling Emergence (Test 2)

Species Results summary for height (lbs ai/A) 

height 

(cm)

NOEC* IC10 95%CI IC25 95%CI IC50 95%CI slope 95%CI 

Cabbage1 8.93-15.8 0.025 0.0087 0.0065-

0.030 

0.12 0.062- 

ND

>0.25 ND N/A N/A 

Carrot 23.4-26.4 0.050 >0.050 ND >0.050 ND >0.050 ND N/A N/A 

Corn2 59.7-82.8 25 6.6 0.13-8.3 >25 ND >25 ND N/A N/A 

Cucumber3 36.4-41.3 0.0050 0.010 0.0062-

ND

>0.098 ND >0.098 ND N/A N/A 

Lettuce 13.7-15.1 0.050 >0.050 ND >0.050 ND >0.050 ND N/A N/A 

Oat 57.6-64.6 0.050 >0.050 ND >0.050 ND >0.050 ND N/A N/A 

Onion4 19.5-23.8 0.050 >0.026 ND-0.098 >0.098 ND >0.098 ND N/A N/A 

Ryegrass 36.9-40.5 0.098 >0.098 ND >0.098 ND >0.098 ND N/A N/A 

Soybean 81.3-111 0.50 >0.48 0.017-ND >0.50 ND >0.50 ND N/A N/A 

Tomato5 43-62.5 0.098 0.116 0.0223-

0.196 

0.205 0.143-ND >0.25 ND N/A N/A 

ND- Not determined. NC- Not calculable. 

*NOEC and all significant inhibitions determined by Dunnett’s Multiple Comparison Test (p<0.05), unless specified otherwise.

1 Significant decrease in cabbage height, inhibition of 17, 20 and 43% at 0.050, 0.098 and 0.25 lb ai/A. 

2 Significant decrease in corn height, inhibition of 28% at 9.8 lb ai/A. 

3 Significant decrease in cucumber height, inhibition of 11 and 11% at 0.010 and 0.050 lb ai/A; inhibitions of 9 and 8% at 0.025 and 0.098 lb 

ai/A were not significant and attributed to atypically high CVs. NOEC was empirically estimated to be 0.0050 lb ai/A due to a clear dose 

response. 

4 Significant decrease in onion height, inhibitions of 18% at 0.098 lb ai/A. 

5 Significant decrease in tomato height, inhibition of 31% at 0.25 lb ai/A (Wilcoxon’s Test with Bonferroni-Holm’s Adjustment).

 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 22 of 39 

Table 6b: Effect of Atrazine on 28-Day Seedling Emergence (Test 2)

Species Results summary for emergence (lbs ai/A) 

% NOEC EC10 95%CI EC25 95%CI EC50 95%CI slope 95%CI 

Cabbage 88-98 0.25 >0.25 ND >0.25 ND >0.25 ND N/A N/A 

Carrot 75-93 0.050 >0.050 ND >0.050 ND >0.050 ND N/A N/A 

Corn 75-88 25 12.5 0.68-ND >25 ND >25 ND N/A N/A 

Cucumber 83-100 0.098 0.080 0.060-ND >0.098 ND >0.098 ND N/A N/A 

Lettuce 83-90 0.050 >0.050 ND >0.050 ND >0.050 ND N/A N/A 

Oat 80-98 0.050 >0.050 ND >0.050 ND >0.050 ND N/A N/A 

Onion 70-88 0.098 >0.098 ND >0.098 ND >0.098 ND N/A N/A 

Ryegrass 85-95 0.098 >0.098 ND >0.098 ND >0.098 ND N/A N/A 

Soybean 68-95 0.50 >0.50 ND >0.50 ND >0.50 ND N/A N/A 

Tomato 83-98 0.25 >0.25 ND >0.25 ND >0.25 ND N/A N/A 

ND- Not determined. NC- Not calculable. 

 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 23 of 39 

Table 6c: Effect of Atrazine on 28-Day Seedling Emergence (Test 2)

Species Results summary for survival, based on # emerged (lbs ai/A) 

% NOEC* EC10 95%CI EC25 95%CI EC50 95%CI slope 95%CI 

Cabbage1 15-100 0.050 0.051 0.014-

0.054 

0.067 0.059-

0.079 

0.107 0.087-

0.143 

N/A N/A 

Carrot 94-100 0.050 >0.050 ND >0.050 ND >0.050 ND N/A N/A 

Corn 95-100 25 >25 ND >25 ND >25 ND N/A N/A 

Cucumber 86-100 0.098 0.078 0.064-ND >0.098 ND >0.098 ND N/A N/A 

Lettuce 100 0.050 >0.050 ND >0.050 ND >0.050 ND N/A N/A 

Oat 95-100 0.050 >0.050 ND >0.050 ND >0.050 ND N/A N/A 

Onion 83-100 0.098 0.064 ND-0.035 >0.098 ND >0.098 ND N/A N/A 

Ryegrass 100 0.098 >0.098 ND >0.098 ND >0.098 ND N/A N/A 

Soybean 100 0.50 >0.50 ND >0.50 ND >0.50 ND N/A N/A 

Tomato2 52-100 0.098 0.116 0.107-

0.125 

0.161 0.134-

0.214 

>0.25 ND N/A N/A 

ND- Not determined. NC- Not calculable. 

*NOEC and all significant inhibitions determined by Fisher’s Exact Test with Bonferroni-Holm’s Adjustment (p<0.05).

1 Significant decrease in cabbage survival, inhibition of 46 and 85% at 0.098 and 0.25 lb ai/A. 

2 Significant decrease in tomato survival, inhibition of 48% at 0.25 lb ai/A. 

Plant Injury Index*; Test 2

Control Cabbage Carrot Corn Cucumber Lettuce Oat Onion Ryegrass Soybean Tomato Formulation 

Blank

0-100 0-100 0 0-100 0-100 0 0 0-100 0 0 0-100 N/A 

* The health rating, including morphological abnormalities ranges from 0 to 100, where 0 indicates no injury or abnormality and 100 indicates 

complete effect (dead plant). 

 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 24 of 39 

Table 7: Effect of Atrazine on 14 Days of 28-Day Seedling Emergence (Test 2a); Not Reported

Species Results summary for height (lbs ai/A) 

height 

(cm)

NOEC IC10 95%CI IC25 95%CI IC50 95%CI slope 95%CI 

Cabbage 2-5.43 NR N/A N/A N/A N/A N/A N/A N/A N/A 

Carrot 9.91-22 NR N/A N/A N/A N/A N/A N/A N/A N/A 

Corn 32-43.8 NR N/A N/A N/A N/A N/A N/A N/A N/A 

Cucumber 17.5-20.9 NR N/A N/A N/A N/A N/A N/A N/A N/A 

Lettuce 4.8-6.31 NR N/A N/A N/A N/A N/A N/A N/A N/A 

Oat 30.3-37.2 NR N/A N/A N/A N/A N/A N/A N/A N/A 

Onion 11.7-14.9 NR N/A N/A N/A N/A N/A N/A N/A N/A 

Ryegrass 21.9-25.2 NR N/A N/A N/A N/A N/A N/A N/A N/A 

Soybean 29.9-38.6 NR N/A N/A N/A N/A N/A N/A N/A N/A 

Tomato 12.7-23.5 NR N/A N/A N/A N/A N/A N/A N/A N/A 

ND- Not determined. NC- Not calculable. NR- Not reported 

 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 25 of 39 

C. VERIFICATION OF STATISTICAL RESULTS BY THE REVIEWER: 

All analyses were conducted comparing treated to the negative control. These analyses were conducted using 

CETIS version 1.8.7.12 and backend settings approved for use by EFED on 9/30/15. Data for each endpoint 

were tested to determine if their distributions were normal and if their variances were homogeneous using 

Shapiro-Wilk’s and Levene’s tests, respectively. Data that satisfied these assumptions were subjected to 

Dunnett’s and William’s tests, and data that did not satisfy these assumptions were subjected to the nonparametric Mann Whitney-U and Jonckheere’s tests. Measured concentrations were used for all analyses. 

Linear (survival and emergence) and nonlinear (height and dry weight) regression models were used to interpret 

EC/ICx values. 

 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 26 of 39 

Table 8: Effect of Atrazine on 14-Day Seedling Emergence (Test 1)

Species Results summary for biomass (lbs ai/A) 

weight (g) NOEC IC05 95%CI IC25 95%CI IC50 95%CI slope 95%CI 

Cabbage1 0.0144-0.0478 0.097 0.00351 N/A0.0215 0.0299 0.00884-

0.0713 

0.132 0.063-

0.277 

N/A N/A 

Carrot 0.0337-0.0414 0.049 0.0154 N/A-0.108 NC N/A NC N/A N/A N/A 

Corn 0.172-0.262 24 9.6 N/A-23.8 24.8 9.85-42.1 NC N/A N/A N/A 

Cucumber 0.297-0.398 0.10 >0.10 N/A >0.10 N/A >0.10 N/A N/A N/A 

Lettuce 0.0339-0.0699 0.049 >0.049 N/A >0.049 N/A >0.049 N/A N/A N/A 

Oat2 0.0727-0.114 0.021 0.0403 N/A-0.043 0.0456 0.0431-

0.0477 

0.0497 0.0488-

0.0507 

N/A N/A 

Onion 0.00658-0.00978 0.10 >0.10 N/A >0.10 N/A >0.10 N/A N/A N/A 

Ryegrass 0.0198-0.0262 0.10 0.143 N/A-44600 >0.10 N/A >0.10 N/A N/A N/A 

Soybean 0.322-0.541 0.44 0.316 0.154-

0.522 

0.68 0.138-

2.31 

NC N/A N/A N/A 

Tomato3 0.0265-0.124 0.047 0.0168 N/A0.0317 0.0527 0.0323-

0.0769 

0.117 0.0884-

0.154 

N/A N/A 

ND- Not determined. NC- Not calculable. 

1 Significant decrease in cabbage weight, inhibition of 62% at the 0.26 lb ai/A (Williams test, p<0.05). 

2 Significant decrease in oat weight, inhibition of 35% at the 0.047 lb ai/A (Dunnett’s test, p<0.05).

3 Significant decrease in tomato weight, inhibitions of 48 and 78% at 0.095 and 0.31 lb ai/A (Williams test, p<0.05). 

 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 27 of 39 

Table 8a: Effect of Atrazine on 14-Day Seedling Emergence (Test 1)

Species Results summary for height (lbs ai/A) 

height 

(cm)

NOEC IC05 95%CI IC25 95%CI IC50 95%CI slope 95%CI 

Cabbage1 2.24-4.77 0.049 0.0137 N/A0.0317 0.0827 0.0504-

0.126 

0.288 0.165-

0.503 

N/A N/A 

Carrot 9.74-10.5 0.049 0.0469 N/A-0.112 NC N/A NC N/A N/A N/A 

Corn 36.7-44.6 24 12.5 N/A-25.3 37.6 N/A-95 NC N/A N/A N/A 

Cucumber 18.5-27.6 0.10 NC N/A NC N/A >0.10 N/A N/A N/A 

Lettuce 3.46-5.57 0.049 >0.049 N/A >0.049 N/A >0.049 N/A N/A N/A 

Oat2 29.9-36.4 0.021 0.0347 N/A0.0645 0.0554 N/A-0.113 NC N/A N/A N/A 

Onion 11.4-16.2 0.10 >0.10 N/A >0.10 N/A >0.10 N/A N/A N/A 

Ryegrass 22.6-24.7 0.10 >0.10 N/A >0.10 N/A >0.10 N/A N/A N/A 

Soybean 31.5-43.1 0.44 0.17 N/A-0.739 0.778 N/A-10.1 NC N/A N/A N/A 

Tomato3 11.5-25.4 0.047 0.0309 0.00724-

0.049 

0.113 0.0845-

0.146 

0.279 0.221-

0.351 

N/A N/A 

ND- Not determined. NC- Not calculable. 

1 Significant decrease in cabbage height, inhibition of 19 and 49% at 0.097 and 0.26 lb ai/A (Williams test, p<0.05). 

2 Significant decrease in oat height, inhibition of 15% at 0.047 lb ai/A (Dunnett’s test, p<0.05).

3 Significant decrease in tomato height, inhibitions of 25 and 53% at 0.095 and 0.31 lb ai/A (Jonckheere-Terpstra Step-Down test, p<0.05). 

 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 28 of 39 

Table 8b: Effect of Atrazine on 14-Day Seedling Emergence (Test 1)

Species Results summary for emergence (lbs ai/A) 

% NOEC EC05 95%CI EC25 95%CI EC50 95%CI slope 95%CI 

Cabbage 85-98 0.26 NC N/A NC N/A NC N/A N/A N/A 

Carrot1 75-93 0.049 0.148 1.06E+13-

0.0246 

0.000524 0.00219-

N/A 

0.0000104 0.000229-

N/A 

N/A N/A 

Corn 85-93 24 NC N/A NC N/A NC N/A N/A N/A 

Cucumber2 83-100 0.025 NC N/A NC N/A NC N/A N/A N/A 

Lettuce 70-90 0.049 NC N/A NC N/A NC N/A N/A N/A 

Oat 78-98 0.047 0.0026 9.85E-06-

0.0068 

0.116 0.0338-

620 

1.62 0.166-

1.02E+08 

0.588 0.128-1.05 

Onion 70-85 0.10 NC N/A NC N/A NC N/A N/A N/A 

Ryegrass 83-93 0.10 NC N/A NC N/A NC N/A N/A N/A 

Soybean 60-75 0.44 NC N/A NC N/A NC N/A N/A N/A 

Tomato 80-93 0.31 NC N/A NC N/A NC N/A N/A N/A 

ND- Not determined. NC- Not calculable. 

1 Carrot dose-response represents an inverse relationship 

2 Significant decrease in cucumber emergence, inhibition of 15% at 0.047 lb ai/A (Mann-Whitney U Two-Sample test, p<0.05); CV%=25%. 

 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 29 of 39 

Table 8c: Effect of Atrazine on 14-Day Seedling Emergence (Test 1)

Species Results summary for survival (lbs ai/A); number survived of planted 

% NOEC EC05 95%CI EC25 95%CI EC50 95%CI slope 95%CI 

Cabbage1 45-98 0.097 0.00775 0.00171-

0.0159 

0.0641 0.0379-

0.114 

0.278 0.148-0.99 1.06 0.626-1.49 

Carrot2 75-93 0.049 0.127 75100-

0.0251 

0.000808 0.00263-

2.44E-07 

0.000024 0.000302-

N/A 

N/A N/A 

Corn 85-93 24 NC N/A NC N/A NC N/A N/A N/A 

Cucumber3 73-100 0.025 NC N/A NC N/A NC N/A N/A N/A 

Lettuce 65-90 0.049 NC N/A NC N/A NC N/A N/A N/A 

Oat 78-98 0.047 0.00206 6.17E-07-

0.00595 

0.125 0.0335-

15100 

2.17 0.179-

1E+10 

0.545 0.0955-

0.994 

Onion 70-85 0.10 NC N/A NC N/A NC N/A N/A N/A 

Ryegrass 83-93 0.10 NC N/A NC N/A NC N/A N/A N/A 

Soybean 60-75 0.44 NC N/A NC NA N/C N/A N/A N/A 

Tomato4 48-93 0.095 0.0034 0.00013-

0.0103 

0.0761 0.0362-

0.229 

0.661 0.223-16.1 0.719 0.333-1.1 

ND- Not determined. NC- Not calculable. 

1 Significant decrease in cabbage survival, inhibition of 47% at 0.26 lb ai/A (Mann-Whitney U Two-Sample test, p<0.05). 

2 Carrot dose-response represents an inverse relationship. 

3 Significant decrease in cucumber survival, inhibition of 26% at 0.047 lb ai/A (Mann-Whitney U Two-Sample test, p<0.05); CV = 50%. 

4 Significant decrease in tomato survival, inhibition of 46% at 0.31 lb ai/A (Mann-Whitney U Two-Sample test, p<0.05). 

Plant Injury Index*; Test 1

Control Cabbage Carrot Corn Cucumber Lettuce Oat Onion Ryegrass Soybean Tomato Formulation 

Blank

0 0-100 0-100 0-100 0-100 0 0 0 0 0-100 0-100 N/A 

* The health rating, including morphological abnormalities ranges from 0 to 100, where 0 indicates no injury or abnormality and 100 indicates 

complete effect (dead plant). 

 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 30 of 39 

Table 9: Effect of Atrazine on 28-Day Seedling Emergence (Test 2)

Species Results summary for biomass (lbs ai/A) 

weight (g) NOEC IC05 95%CI IC25 95%CI IC50 95%CI slope 95%CI 

Cabbage1 0.161-0.925 0.0099 0.00143 N/A-0.01 0.0177 0.00657-

0.0389 

0.102 0.0496-

0.21 

N/A N/A 

Carrot 0.454-0.633 0.049 >0.049 N/A >0.049 N/A >0.049 N/A N/A N/A 

Corn 0.799-1.6 24 NC N/A NC N/A NC N/A N/A N/A 

Cucumber 1.8-2.29 0.10 0.0192 N/A-0.252 NC N/A NC N/A N/A N/A 

Lettuce 0.755-1.14 0.049 0.0222 N/A0.0409 0.0475 0.0333-

0.0621 

0.0804 0.0229-

0.282 

N/A N/A 

Oat 0.458-0.592 0.047 >0.047 N/A >0.047 N/A >0.047 N/A N/A N/A 

Onion2 0.0285-0.0557 0.025 0.00432 N/A-0.016 0.0341 0.0153-

0.0645 

0.144 0.05-

0.413 

N/A N/A 

Ryegrass 0.187-0.225 0.10 0.0285 N/A0.0887 0.161 N/A-0.65 NC N/A N/A N/A 

Soybean 0.938-1.43 0.44 0.0493 N/A-0.326 0.639 0.00688-

3.58 

NC N/A N/A N/A 

Tomato3 0.426-1.46 0.095 0.0776 N/A-0.118 0.146 0.081-

0.205 

0.225 0.181-

0.28 

N/A N/A 

ND- Not determined. NC- Not calculable. 

1 Significant decrease in cabbage weight, inhibition of 35, 45, 34 and 83% at 0.022, 0.049, 0.097 and 0.26 lb ai/A (Williams test, p<0.05). 

2 Significant decrease in onion weight, inhibition of 35 and 49% at the 0.047 and 0.10 lb ai/A (Williams test, p<0.05). 

3 Significant decrease in tomato weight, inhibitions of 69% at 0.31 lb ai/A (Dunnett’s test, p<0.05). 

 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 31 of 39 

Table 9a: Effect of Atrazine on 28-Day Seedling Emergence (Test 2)

Species Results summary for height (lbs ai/A) 

height 

(cm)

NOEC IC05 95%CI IC25 95%CI IC50 95%CI slope 95%CI 

Cabbage1 8.93-15.8 0.0046 0.0063 4.87E-05-

0.0178 

0.103 0.059-0.17 0.724 0.174-3.01 N/A N/A 

Carrot 23.4-26.4 0.049 >0.049 N/A >0.049 N/A >0.049 N/A N/A N/A 

Corn2 59.7-82.8 5.0 1.31 N/A-7.24 38 3.03-196 NC N/A N/A N/A 

Cucumber3 36.4-41.3 0.0047 0.00376 7.69E-05-

0.0264 

3.17 2.99E-05-

290 

NC N/A N/A N/A 

Lettuce 13.7-15.1 0.049 >0.049 N/A >0.049 N/A >0.049 N/A N/A N/A 

Oat 57.6-64.6 0.047 >0.047 N/A >0.047 N/A >0.047 N/A N/A N/A 

Onion4 19.5-23.8 0.025 0.00311 N/A0.0204 0.384 0.0116-

3.81 

10.9 2.29E-05-

5200000 

N/A N/A 

Ryegrass 36.9-40.5 0.10 NC N/A NC N/A NC N/A N/A N/A 

Soybean 81.3-111 0.44 0.0522 N/A-0.341 1.4 N/A-25.8 NC N/A N/A N/A 

Tomato5 43-62.5 0.095 0.246 N/A-0.267 0.302 0.283-

0.319 

0.349 0.34-0.358 N/A N/A 

ND- Not determined. NC- Not calculable. 

1 Significant decrease in cabbage height, inhibition of 12, 14, 17, 20 and 43% at 0.0099, 0.022, 0.049, 0.097 and 0.26 lb ai/A (Williams test, 

p<0.05). 

2 Significant decrease in corn height, inhibition of 28% at 9.9 lb ai/A (Dunnett’s test, p<0.05).

3 Significant decrease in cucumber height, inhibition of 11 and 11% at 0.0099 and 0.047 lb ai/A (Dunnett’s test, p<0.05).

4 Significant decrease in onion height, inhibitions of 15 and 18% at 0.047 and 0.10 lb ai/A (Williams test, p<0.05). 

5 Significant decrease in tomato height, inhibition of 31% at 0.31 lb ai/A (Dunnett’s test, p<0.05).

 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 32 of 39 

Table 9b: Effect of Atrazine on 28-Day Seedling Emergence (Test 2)

Species Results summary for emergence (lbs ai/A) 

% NOEC EC05 95%CI EC25 95%CI EC50 95%CI slope 95%CI 

Cabbage 88-98 0.26 NC N/A NC N/A NC N/A N/A N/A 

Carrot 75-93 0.049 NC N/A NC N/A NC N/A N/A N/A 

Corn 75-88 24 NC N/A NC N/A NC N/A N/A N/A 

Cucumber 83-100 0.10 NC N/A NC N/A NC N/A N/A N/A 

Lettuce 83-90 0.049 NC N/A NC N/A NC N/A N/A N/A 

Oat 80-98 0.047 NC N/A NC N/A NC N/A N/A N/A 

Onion 70-88 0.10 NC N/A NC N/A NC N/A N/A N/A 

Ryegrass 85-95 0.10 NC N/A NC N/A NC N/A N/A N/A 

Soybean 68-95 0.44 >0.44 N/A >0.44 N/A >0.44 N/A N/A N/A 

Tomato 83-98 0.31 NC N/A NC N/A NC N/A N/A N/A 

ND- Not determined. NC- Not calculable. 

 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 33 of 39 

Table 9c: Effect of Atrazine on 28-Day Seedling Emergence (Test 2)

Species Results summary for survival (lbs ai/A); number survived of planted 

% NOEC EC05 95%CI EC25 95%CI EC50 95%CI slope 95%CI 

Cabbage1 15-98 0.049 0.00466 0.00177-

0.00838 

0.0284 0.0186-

0.0401 

0.1 0.07-0.161 1.24 0.894-1.58 

Carrot 73-93 0.049 NC N/A NC N/A NC N/A N/A N/A 

Corn 73-85 24 NC N/A NC N/A NC N/A N/A N/A 

Cucumber2 73-100 0.047 0.0152 0.00328-

0.0297 

0.193 0.0805-

3.73 

1.12 0.265-302 0.88 0.346-1.41 

Lettuce 83-90 0.049 NC N/A NC N/A NC N/A N/A N/A 

Oat 80-98 0.047 NC N/A NC N/A NC N/A N/A N/A 

Onion 70-80 0.10 NC N/A NC N/A NC N/A N/A N/A 

Ryegrass 85-95 0.10 NC N/A NC N/A NC N/A N/A N/A 

Soybean 68-95 0.44 >0.44 N/A >0.44 N/A >0.44 N/A N/A N/A 

Tomato3 45-93 0.095 0.00916 0.00152-

0.0201 

0.103 0.0565-

0.255 

0.557 0.233-4.46 0.922 0.497-1.35 

ND- Not determined. NC- Not calculable. 

1 Significant decrease in cabbage survival, inhibition of 46 and 85% at 0.097 and 0.26 lb ai/A (Dunnett’s test, p<0.05). 

2 Significant decrease in cucumber survival, inhibition of 22% at 0.10 lb ai/A (Mann-Whitney U Two-Sample test, p<0.05); CV = 41%. 

3 Significant decrease in tomato survival, inhibition of 46% at 0.31 lb ai/A (Mann-Whitney U Two-Sample test, p<0.05). 

Plant Injury Index*; Test 2

Control Cabbage Carrot Corn Cucumber Lettuce Oat Onion Ryegrass Soybean Tomato Formulation 

Blank

0-100 0-100 0 0-100 0-100 0 0 0-100 0 0 0-100 N/A 

* The health rating, including morphological abnormalities ranges from 0 to 100, where 0 indicates no injury or abnormality and 100 indicates 

complete effect (dead plant). 

 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 34 of 39 

Table 10: Effect of Atrazine on 14 days of 28-Day Seedling Emergence (Test 2a)

Species Results summary for height (lbs ai/A) 

height 

(cm)

NOEC IC05 95%CI IC25 95%CI IC50 95%CI slope 95%CI 

Cabbage1 2-5.43 0.0099 0.00257 N/A0.00834 0.0262 0.0158-

0.0409 

0.132 0.0872-

0.199 

N/A N/A 

Carrot 9.91-22 0.049 >0.049 N/A >0.049 N/A >0.049 N/A N/A N/A 

Corn2 32-43.8 5.0 1.5 N/A-6.58 34.6 5.22-131 307 0.311-

303000 

N/A N/A 

Cucumber3 17.5-20.9 0.047 0.0365 N/A0.0759 0.23 N/A-0.848 NC N/A N/A N/A 

Lettuce 4.8-6.31 0.049 0.0307 N/A0.0627 0.0645 N/A-0.152 NC N/A N/A N/A 

Oat 30.3-37.2 0.047 >0.047 N/A >0.047 N/A >0.047 N/A N/A N/A 

Onion 11.7-14.9 0.10 0.0205 N/A0.0693 0.159 0.00491-

0.625 

NC N/A N/A N/A 

Ryegrass 21.9-25.2 0.10 >0.10 N/A >0.10 N/A >0.10 N/A N/A N/A 

Soybean 29.9-38.6 0.44 >0.44 N/A >0.44 N/A >0.44 N/A N/A N/A 

Tomato4 12.7-23.5 0.095 0.049 N/A0.0808 0.164 0.119-

0.214 

0.378 0.275-0.52 N/A N/A 

ND- Not determined. NC- Not calculable. 

1 Significant decrease in cabbage height, inhibition of 28, 34, 42 and 63% at 0.022, 0.049, 0.097 and 0.26 lb ai/A (Jonckheere-Terpstra StepDown test, p<0.05). 

2 Significant decrease in corn height, inhibition of 26% at 9.9 lb ai/A (Dunnett’s test, p<0.05). 

3 Significant decrease in cucumber height, inhibition of 16% at 0.10 lb ai/A (Dunnett’s test, p<0.05). 

4 Significant decrease in tomato height, inhibition of 45% at 0.31 lb ai/A (Dunnett’s test, p<0.05). 

 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 35 of 39 

Test 1, 14 days 

Most sensitive monocot: Oat, based on dry weight 

EC50/IC50: 0.0497 lb ai/A 95% C.I.: 0.0488-0.0507 lb ai/A 

EC25/IC25: 0.0456 lb ai/A 95% C.I.: 0.0431-0.0477 lb ai/A 

EC05/IC05: 0.0403 lb ai/A 95% C.I.: N/A-0.043 lb ai/A 

NOEC: 0.021 lb ai/A 

Slope: N/A 95% C.I.: N/A 

 

Most sensitive dicot: Cabbage, based on dry weight 

EC50/IC50: 0.132 lb ai/A 95% C.I.: 0.063-0.277 lb ai/A 

EC25/IC25: 0.0299 lb ai/A 95% C.I.: 0.00884-0.0713 lb ai/A 

EC05/IC05: 0.00351 lb ai/A 95% C.I.: N/A-0.0215 lb ai/A 

NOEC: 0.097 lb ai/A 

Slope: N/A 95% C.I.: N/A 

Test 2, 28 days 

Most sensitive monocot: Onion, based on dry weight 

EC50/IC50: 0.144 lb ai/A 95% C.I.: 0.050-0.413 lb ai/A 

EC25/IC25: 0.0341 lb ai/A 95% C.I.: 0.0153-0.0645 lb ai/A 

EC05/IC05: 0.00432 lb ai/A 95% C.I.: N/A-0.016 lb ai/A 

NOEC: 0.025 lb ai/A 

Slope: N/A 95% C.I.: N/A 

Most sensitive dicot: Cabbage, based on dry weight 

EC50/IC50: 0.102 lb ai/A 95% C.I.: 0.0496-0.21 lb ai/A 

EC25/IC25: 0.0177 lb ai/A 95% C.I.: 0.00657-0.0389 lb ai/A 

EC05/IC05: 0.00143 lb ai/A 95% C.I.: N/A-0.01 lb ai/A 

NOEC: 0.0099 lb ai/A 

Slope: N/A 95% C.I.: N/A 

Test 2a, 14 days of 28 days 

Most sensitive monocot: Onion, based on height (only endpoint analyzed) 

EC50/IC50: NC 95% C.I.: N/A 

EC25/IC25: 0.159 lb ai/A 95% C.I.: 0.00491-0.625 lb ai/A 

EC05/IC05: 0.0205 lb ai/A 95% C.I.: N/A-0.0693 lb ai/A 

NOEC: 0.10 lb ai/A 

Slope: N/A 95% C.I.: N/A 

Most sensitive dicot: Cabbage, based on height (only endpoint analyzed) 

EC50/IC50: 0.132 lb ai/A 95% C.I.: 0.0872-0.199 lb ai/A 

EC25/IC25: 0.0262 lb ai/A 95% C.I.: 0.0158-0.0409 lb ai/A 

EC05/IC05: 0.00257 lb ai/A 95% C.I.: N/A-0.00834 lb ai/A 

NOEC: 0.0099 lb ai/A 

Slope: N/A 95% C.I.: N/A 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

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D. STUDY DEFICIENCIES: 

1. The physico-chemical properties of the test material were not reported. 

2. Survival at 14 days in the 28 day study was not analyzed by the study author, and raw data were not 

provided. The reviewer could not perform statistical analysis or report results for this endpoint. 

E. REVIEWER’S COMMENTS: The reviewer and study author results are in general agreement. There were 

some differences in NOEC and ECx values. These slight discrepancies are likely due to the reviewer using measured 

concentrations and differences in statistical analysis methods. 

Test 1, 14 days 

The most sensitive monocot, based on the study author's results, was oat based on dry weight with NOAEC and 

EC25 values of 0.025 lb ai/A and 0.039 lb ai/A, respectively; the most sensitive dicot was cabbage based on dry 

weight with NOAEC and EC25 values of 0.098 and 0.010 lb ai/A, respectively. The most sensitive monocot, 

based on the reviewer’s results, was oat based on dry weight with NOAEC and EC25 values of 0.021 lb ai/A and 

0.0456 lb ai/A, respectively; the most sensitive dicot was cabbage based on dry weight with NOAEC and EC25

values of 0.097 and 0.0299 lb ai/A, respectively. 

Test 2, 28 days 

The most sensitive monocot, based on the study author's results, was onion based on dry weight with NOAEC 

and EC25 values of 0.025 lb ai/A and 0.031 lb ai/A, respectively; the most sensitive dicot was cabbage based on 

dry weight with NOAEC and EC25 values of 0.010 and 0.014 lb ai/A, respectively. The most sensitive 

monocot, based on the reviewer’s results, was onion based on dry weight with NOAEC and EC25 values of 

0.025 lb ai/A and 0.0341 lb ai/A, respectively; the most sensitive dicot was cabbage based on dry weight with 

NOAEC and EC25 values of 0.0099 and 0.0177 lb ai/A, respectively. 

Test 2a, 14 days of 28 days 

The most sensitive monocot and dicot could not be determined for the study author because the data were not 

analyzed. The most sensitive monocot, based on the reviewer’s results, was onion based on height with 

NOAEC and EC25 values of 0.10 lb ai/A and 0.159 lb ai/A, respectively; the most sensitive dicot was cabbage 

based on height with NOAEC and EC25 values of 0.0099 and 0.0262 lb ai/A, respectively. 

The in-life portion of this study was initiated on April 4, 2014 to September 14, 2014. 

F. CONCLUSIONS: 

This toxicity study is classified as acceptable for the herein labeled “Test 1-14-day Study”. The concurrent 28-

day study labeled here as Test 2 and Test 2a is classified as supplemental, as the study design did not allow for 

dry weight endpoints at the 14-day period, did not provide survival at 14-days. 

Test 1, 14 days 

The most sensitive monocot, based on the reviewer’s results, was oat based on dry weight with NOAEC and 

EC25 values of 0.021 lb ai/A and 0.0456 lb ai/A, respectively; the most sensitive dicot was cabbage based on dry 

weight with NOAEC and EC25 values of 0.097 and 0.0299 lb ai/A, respectively. 

Most sensitive monocot and EC25/IC25: Oat (dry weight, 0.0456 lb ai/A). 

Most sensitive dicot and EC25/IC25: Cabbage (dry weight, 0.0299 lb ai/A). 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 37 of 39 

Test 2, 28 days 

The most sensitive monocot, based on the reviewer’s results, was onion based on dry weight with NOAEC and 

EC25 values of 0.025 lb ai/A and 0.0341 lb ai/A, respectively; the most sensitive dicot was cabbage based on dry 

weight with NOAEC and EC25 values of 0.0099 and 0.0177 lb ai/A, respectively. 

Most sensitive monocot and EC25/IC25: Onion (dry weight, 0.0341 lb ai/A). 

Most sensitive dicot and EC25/IC25: Cabbage (dry weight, 0.0177 lb ai/A). 

Test 2a, 14 days of 28 days 

The most sensitive monocot, based on the reviewer’s results, was onion based on height with NOAEC and EC25

values of 0.10 lb ai/A and 0.159 lb ai/A, respectively; the most sensitive dicot was cabbage based on height with 

NOAEC and EC25 values of 0.0099 and 0.0262 lb ai/A, respectively. 

Most sensitive monocot and EC25/IC25: Onion (height, 0.159 lb ai/A). 

Most sensitive dicot and EC25/IC25: Cabbage (height, 0.0262 lb ai/A). 

 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 38 of 39 

Study author Growth Rate Results: 

The study author analyzed and reported growth rate endpoint results for shoot length and dry weight. Results are for 

Test 1, 14 day study and Test 2, 14-28 days. For the Test 2, 14-28 days, the study author determined dry weight 

growth rate using the dry weights at the end of the 14 day study relative to the dry weights at the end of the 28 day 

study. All results using nominal concentration are in g ai/ha. 
Data Evaluation Record on the Acute Toxicity of Atrazine to Terrestrial Vascular Plants: 

Seedling Emergence

PMRA Submission Number {..............} EPA MRID Number 49639102

Page 39 of 39 

III. REFERENCES: 

1. Ives, Michael, 2013. CETIS, Comprehensive Environmental Toxicity Information SystemTM. User's Guide. 

Tidepool Scientific Software, McKinleyville, California. 

2. Chetram, R.S., 1989. Tier 2 Seedling Emergence Nontarget Phytotoxicity Test. Pan-Agricultural 

Laboratory, Inc. Madera, California, Final report date, August 23,1989. 346 pp. 

3. OECD, 1998. OECD Series on Principles of Good Laboratory Practice and Compliance Monitoring. 

Number 1. OECD Principles on Good Laboratory Practice (as revised in 1997). Environment Directorate 

Chemicals Group and Management Committee. ENV/MC/CHEM(98)17. OECD Paris, France. 41pp. 

4. OECD, 2006. OECD Guidelines for the Testing of Chemicals. Terrestrial Plant Test 208: Seedling 

Emergence and Seedling Growth Test. 

5. U.S. EPA, 1989. Federal Insecticide, Fungicide and Rodenticide Act (FIFRA); Good Laboratory Practice 

Standards; Final Rule (40 CFR, Part 160). Federal Register, 48 (230); 34052-34074. 

6. U.S. EPA, 2002. Short-term methods for estimating the chronic toxicity of effluents and receiving waters to 

freshwater organisms. Third edition. Office of Water, U. S. Environmental Protection Agency, Washington, 

DC 20460. EPA/82l/R-02/013. 

7. U.S. EPA, 2012. Office of Chemical Safety and Pollution Prevention. Ecological Effects Test Guideline, 

OCSPP 850.4150. Vegetative Vigor. EPA 712-C-12-011. January 2012. U.S. Environmental Protection 

Agency, Washington, D.C.