Jump to main content.


Fluridone (CASRN 59756-60-4)

IRIS
List of IRIS Substances




view QuickView

Main Contents

Go

0054

Fluridone; CASRN 59756-60-4

Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data, as outlined in the IRIS assessment development process. Sections I (Health Hazard Assessments for Noncarcinogenic Effects) and II (Carcinogenicity Assessment for Lifetime Exposure) present the conclusions that were reached during the assessment development process. Supporting information and explanations of the methods used to derive the values given in IRIS are provided in the guidance documents located on the IRIS website.

STATUS OF DATA FOR Fluridone

File First On-Line 01/31/1987

Category (section)
Status
Last Revised
Oral RfD Assessment (I.A.) on-line 09/01/1990
Inhalation RfC Assessment (I.B.) no data
Carcinogenicity Assessment (II.) no data

_I.  Chronic Health Hazard Assessments for Noncarcinogenic Effects

_I.A. Reference Dose for Chronic Oral Exposure (RfD)

Substance Name — Fluridone
CASRN — 59756-60-4
Primary Synonym — Sonar
Last Revised — 09/01/1990

The oral Reference Dose (RfD) is based on the assumption that thresholds exist for certain toxic effects such as cellular necrosis. It is expressed in units of mg/kg-day. In general, the RfD is an estimate (with uncertainty spanning perhaps an order of magnitude) of a daily exposure to the human population (including sensitive subgroups) that is likely to be without an appreciable risk of deleterious effects during a lifetime. Please refer to the Background Document for an elaboration of these concepts. RfDs can also be derived for the noncarcinogenic health effects of substances that are also carcinogens. Therefore, it is essential to refer to other sources of information concerning the carcinogenicity of this substance. If the U.S. EPA has evaluated this substance for potential human carcinogenicity, a summary of that evaluation will be contained in Section II of this file.

__I.A.1. Oral RfD Summary

Critical Effect
Experimental Doses*
UF
MF
RfD

Glomerulonephritis,
atrophic testes, eye
keratitis; decreased
body weight and organ
weights

2-Year Rat Feeding Study

Elanco Products, 1980a

NOEL: 200 ppm
(8 mg/kg/day)

LEL: 650 ppm
(25 mg/kg/day)
100
1
8E-2
mg/kg/day

*Conversion Factors -- Dose in mg/kg/day provided by author of study

__I.A.2. Principal and Supporting Studies (Oral RfD)

Elcanco Products Company, Division of Eli Lilly and Company. 1980a. MRID No. 00103251, 00103305. Available from EPA. Write to FOI, EPA, Washington, DC 20460.

Three studies were conducted concurrently, using Fischer rats fed the same dietary levels of Fluridone [0, 200, 650, 2000 ppm (0, 8, 25, 81 mg/kg/day)]. The first study was a 1-year feeding study (R-1126) in which 120 animals were divided into four groups of 15 animals/sex/dietary level. The other two studies were reported to be replicate 2-year oncogenic assays (Nos. R-1136 and R-1146), in which 240 animals per assay were divided into four groups of 30 animals/sex/dietary level. These three studies constitute a 2-year study with 75 animals/sex/dietary level of which 15 animals/sex/dietary level were sacrificed at 12 months. Effects observed at 650 ppm included glomerulonephritis, atrophic testes, eye keratitis, decreased body weight and organ weights.

__I.A.3. Uncertainty and Modifying Factors (Oral RfD)

UF — An uncertainty factor of 100 was used to account for the inter- and intraspecies differences.

MF — None

__I.A.4. Additional Studies/Comments (Oral RfD)

Data Considered for Establishing the RfD

1) 2-Year Feeding (oncogenic) - rat: Principal study - see previous description; core grade minimum

2) 1-Year Feeding - dog: Systemic NOEL=75 mg/kg/day; Systemic LEL=150 mg/kg/day (weight loss, increased liver weight and alkaline phosphatase); core grade minimum (Elanco Products, 1981)

3) 3-Generation Reproduction - rat: Teratogenic, Maternal and Fetotoxic NOEL=2000 ppm (100 mg/kg/day) (HDT); LEL=none; Pup toxic NOEL=650 ppm (32.5 mg/kg/day); Pup toxic LEL=2000 ppm (100 mg/kg/day) (pup weight); core grade minimum for reproduction, supplementary for teratology (Elanco Products, 1980b)

4) Teratology - Rat: Maternal NOEL=100 mg/kg/day; Maternal LEL=300 mg/kg/day (decreased body weight); Developmental NOEL=300 mg/kg/day; Developmental LEL=1000 mg/kg/day (decreased fetal weight, delayed ossification); Teratogenic NOEL=1000 mg/kg/day (HDT); LEL=none; core grade minimum (Elanco Products, 1986)

5) Teratology - rabbit: Teratogenic NOEL=750 mg/kg/day (HDT); Teratogenic LEL=none; Maternal NOEL=125 mg/kg/day; Maternal LEL=30 mg/kg/day (body weight, abortion); Fetal NOEL=125 mg/kg/day; Fetal LEL=300 mg/kg/day (resorptions); core grade minimum (Elanco Products, 1980c)

Other Data Reviewed:

1) 2-Year Feeding (oncogenic) - mouse: Clinical NOEL equal to or greater than the HDT (no deaths, no toxicities, no histopathological lesions); Dose- dependent, increased AP in males [NOEL=100 ppm (15 mg/kg/day)]; MTD was not used, and food consumption not determined; core grade minimum (Elanco Products, 1982)

2) 3-Month Feeding - rat: Systemic NOEL=none; LEL=166 mg/kg/day (LDT; increased liver weight); core grade minimum (Elanco Products, 1978a)

3) 3-Month Feeding - dog: Systemic NOEL=200 mg/kg/day (HDT); LEL=none; core grade minimum (Elanco Products, 1978b)

Data Gap(s): None

__I.A.5. Confidence in the Oral RfD

Study — Medium
Database — High
RfD — High

The critical study is of adequate quality and is given a medium confidence rating. Additional studies are supportive and of good quality and therefore, the database is given a high confidence rating. High confidence in the RfD follows.

__I.A.6. EPA Documentation and Review of the Oral RfD

Pesticide Registration Files

Agency Work Group Review — 11/21/1985, 01/21/1988

Verification Date — 01/21/1988

Screening-Level Literature Review Findings — A screening-level review conducted by an EPA contractor of the more recent toxicology literature pertinent to the RfD for Fluridone conducted in September 2002 did not identify any critical new studies. IRIS users who know of important new studies may provide that information to the IRIS Hotline at hotline.iris@epa.gov or (202)566-1676.

__I.A.7. EPA Contacts (Oral RfD)

Please contact the IRIS Hotline for all questions concerning this assessment or IRIS, in general, at (202)566-1676 (phone), (202)566-1749 (FAX) or hotline.iris@epa.gov (internet address).

Top of page


_I.B. Reference Concentration for Chronic Inhalation Exposure (RfC)

Substance Name — Fluridone
CASRN — 59756-60-4
Primary Synonym — Sonar

Not available at this time.

Top of page


_II.  Carcinogenicity Assessment for Lifetime Exposure

Substance Name — Fluridone
CASRN — 59756-60-4
Primary Synonym — Sonar

Not available at this time.

Top of page


_III.  [reserved]
_IV.  [reserved]
_V.  [reserved]


_VI.  Bibliography

Substance Name — Fluridone
CASRN — 59756-60-4
Primary Synonym — Sonar
Last Revised — 09/01/1990

_VI.A. Oral RfD References

Elcanco Products Company, Division of Eli Lilly and Company. 1978a. MRID No. 00135208. Available from EPA. Write to FOI, EPA, Washington, DC 20460.

Elcanco Products Company, Division of Eli Lilly and Company. 1978b. MRID No. 0082344. Available from EPA. Write to FOI, EPA, Washington, DC 20460.

Elcanco Products Company, Division of Eli Lilly and Company. 1980a. MRID No. 00103251, 00103305. Available from EPA. Write to FOI, EPA, Washington, DC 20460.

Elcanco Products Company, Division of Eli Lilly and Company. 1980b. MRID No. 00103304. Available from EPA. Write to FOI, EPA, Washington, DC 20460.

Elcanco Products Company, Division of Eli Lilly and Company. 1980c. MRID No. 00103302. Available from EPA. Write to FOI, EPA, Washington, DC 20460.

Elcanco Products Company, Division of Eli Lilly and Company. 1981. MRID No. 00103336. Available from EPA. Write to FOI, EPA, Washington, DC 20460.

Elcanco Products Company, Division of Eli Lilly and Company. 1982. MRID No. 00103252, 00103305. Available from EPA. Write to FOI, EPA, Washington, DC 20460.

Elcanco Products Company, Division of Eli Lilly and Company. 1986. MRID No. 00159963. Available from EPA. Write to FOI, EPA, Washington, DC 20460.

Top of page


_VI.B. Inhalation RfC References

None

Top of page


_VI.C. Carcinogenicity Assessment References

None

Top of page


_VII.  Revision History

Substance Name — Fluridone
CASRN — 59756-60-4
Primary Synonym — Sonar

Date
Section
Description
08/22/1988 I.A. Oral RfD summary replaced; RfD not changed
09/01/1990 I.A.4. Citations added
09/01/1990 VI. Bibliography on-line
04/01/1997 III., IV., V. Drinking Water Health Advisories, EPA Regulatory Actions, and Supplementary Data were removed from IRIS on or before April 1997. IRIS users were directed to the appropriate EPA Program Offices for this information.
12/03/2002 I.A.6. Screening-Level Literature Review Findings message has been added.

Top of page


_VIII.  Synonyms

Substance Name — Fluridone
CASRN — 59756-60-4
Primary Synonym — Sonar
Last Revised — 01/31/1987

Top of page

Recent Additions | Search IRIS | IRIS Home | NCEA Home | ORD Home


Jump to main content.