Diuron (CASRN 330-54-1)
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0233
Diuron;
CASRN 330-54-1
Health assessment information on a chemical substance is included in IRIS
only after a comprehensive review of chronic toxicity data by U.S. EPA
health scientists from several Program Offices and the Office of Research
and Development. The summaries presented in Sections I and II represent
a consensus reached in the review process. Background information and
explanations of the methods used to derive the values given in IRIS are
provided in the Background Documents.
STATUS OF DATA FOR Diuron
File First On-Line 09/30/1987
Category (section) |
Status |
Last Revised |
---|---|---|
Oral RfD Assessment (I.A.) | on-line | 08/22/1988 |
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 — Diuron
CASRN — 330-54-1
Last Revised — 08/22/1988
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 |
---|---|---|---|---|
Abnormal pigments in 2-Year Dog Feeding du Pont, 1964a |
NOEL: 25 ppm LEL: 125 ppm |
300
|
1
|
2E-3
mg/kg/day |
*Conversion Factors -- 1 ppm = 0.025 mg/kg/day (assumed dog food consumption)
__I.A.2. Principal and Supporting Studies (Oral RfD)
E.I. du Pont de Nemours and Company, Inc. 1964a. MRID No. 00017763, 00091192. Available from EPA. Write to FOI, EPA, Washington, DC 20460.
A 2-year dog feeding study in 2 male and 3 female dogs was done at levels of 0, 25, 125, 250, and 1250 ppm (0, 0.625, 3.125, 6.25, and 31.25 mg/kg/day) diuron in the diet. The 1250 ppm (31.25 mg/kg/day) dose caused weight loss, depressed red cell counts, erythrogenic activity in bone marrow, elevated liver weight, and increased pigment deposition in liver cells. Also, abnormal pigments were found in the blood of males at levels higher than 25 ppm (0.625 mg/kg/day) and females above 125 ppm (3.125 mg/kg/day).
__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. An additional UF of 3 was used to account for the fact that the database on chronic toxicity is of poor quality and incomplete.
MF — None
__I.A.4. Additional Studies/Comments (Oral RfD)
Data Considered for Establishing the RfD
1) 2-Year Feeding - dog: Principal study - see previous description; core grade minimum
2) 2-Year Feeding/(oncogenic) - rat: Systemic NOEL=25 ppm (1.25 mg/kg/day); Systemic LEL=125 ppm (6.25 mg/kg/day) (slight anemia, enlarged spleens, increased erythrogenic activity in bone marrow and abnormal pigments in the blood); no core grade (du Pont, 1964b)
3) 3-Generation Reproduction - rat: Reproductive NOEL=125 ppm (6.25 mg/kg/day) (only dose tested); Reproductive LEL=none; Systemic NOEL=none; Systemic LEL=125 ppm (6.25 mg/kg/day) (body weight depression in F2b and F3a litters); no core grade (du Pont, 1964b)
4) Teratology - rat: Fetotoxic NOEL=none; Fetotoxic LEL=125 mg/kg/day (LDT; wavy ribs, extra ribs, and delayed ossification); Teratogenic NOEL=500 mg/kg/day) (HDT); Teratogenic LEL=none; core grade supplementary (Khera et al., 1979)
Other Data Reviewed:
1) 3-Month Feeding - rat: Systemic NOEL=50 ppm (2.5 mg/kg/day); Systemic LEL=500 ppm (25 mg/kg/day) (at 5000 ppm growth retardation, methemoglobinenemia); no core grade (du Pont, 1981)
Data Gap(s): Rat Teratology Study; Rabbit Teratology Study
__I.A.5. Confidence in the Oral RfD
Study — Low
Database — Low
RfD — Low
The critical study is of fair quality and is given a low confidence rating. The database is given a low confidence rating since the database on chronic toxicity is of poor quality and incomplete. Low confidence in the RfD follows.
__I.A.6. EPA Documentation and Review of the Oral RfD
Source Document — This assessment is not presented in any existing U.S. EPA document.
Other EPA Documentation — Pesticide Registration Standard, September 1983; Pesticide Registration Files
Agency Work Group Review — 06/10/1986, 03/18/1987, 07/20/1988
Verification Date — 03/18/1987
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 Diuron conducted in August 2003 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).
_I.B. Reference Concentration for Chronic Inhalation Exposure (RfC)
Substance Name — Diuron
CASRN — 330-54-1
Not available at this time.
_II. Carcinogenicity Assessment for Lifetime Exposure
Substance Name — Diuron
CASRN — 330-54-1
This substance/agent has not undergone a complete evaluation and determination under US EPA's IRIS program for evidence of human carcinogenic potential.
_III.
[reserved]
_IV. [reserved]
_V. [reserved]
_VI. Bibliography
Substance Name — Diuron
CASRN — 330-54-1
Last Revised — 10/01/1990
_VI.A. Oral RfD References
E.I. du Pont de Nemours and Company, Inc. 1964a. MRID No. 00017763, 00091192. Available from EPA. Write to FOI, EPA, Washington, DC 20460.
E.I. du Pont de Nemours and Company, Inc. 1964b. MRID No. 00017763, 00080899. Available from EPA. Write to FOI, EPA, Washington, DC 20460.
Khera, K.S., C. Whalen, G. Trivett and G. Angers. 1979. Teratogenicity studies on pesticidal formulations of dimethoate, diuron and lindane in rats. Bull. Environ. Contam. Toxicol. 22: 522-529.
E.I. du Pont de Nemours and Company, Inc. 1981. MRID No. 00068036. Available from EPA. Write to FOI, EPA, Washington, DC 20460.
_VI.B. Inhalation RfD References
None
_VI.C. Carcinogenicity Assessment References
None
_VII. Revision History
Substance Name — Diuron
CASRN — 330-54-1
Date |
Section |
Description |
---|---|---|
03/01/1988 | I.A.5. | Confidence levels revised |
08/22/1988 | I.A.1. | Oral RfD corrected |
12/01/1989 | VI. | Bibliography on-line |
10/01/1990 | III.A. | Health Advisory on-line |
10/01/1990 | VI.D. | Health Advsiory references added |
01/01/1992 | IV. | Regulatory actions updated |
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. |
10/28/2003 | I.A.6. | Screening-Level Literature Review Findings message has been added. |
_VIII. Synonyms
Substance Name — Diuron
CASRN — 330-54-1
Last Revised — 09/30/1987
- 330-54-1
- AF 101
- CEKIURON
- CRISURON
- DAILON
- DCMU
- DIATER
- 3-(3,4-DICHLOOR-FENYL)-1,1-DIMETHYLUREUM
- DICHLORFENIDIM
- 3-(3,4-DICHLOROPHENOL)-1,1-DIMETHYLUREA
- 3-(3,4-DICHLOROPHENYL)-1,1-DIMETHYLUREA
- 1-(3,4-DICHLOROPHENYL)-3,3-DIMETHYLUREE
- 3-(3,4-DICHLOR-PHENYL)-1,1-DIMETHYL-HARNSTOFF
- 3-(3,4-DICLORO-FENYL)-1,1-DIMETIL-UREA
- 1,1-DIMETHYL-3-(3,4-DICHLOROPHENYL)UREA
- DI-ON
- DIREX 4L
- DIUREX
- DIUROL
- Diuron
- DIURON 4L
- DMU
- DREXEL
- DREXEL DIURON 4L
- DURAN
- DYNEX
- FARMCO DIURON
- HERBATOX
- HW 920
- KARMEX
- KARMEX DW
- MARMER
- NA 2767
- N'-(3,4-DICHLOROPHENYL)-N,N-DIMETHYLUREA
- SUP'R FLO
- TELVAR
- UNIDRON
- UREA, 3-(3,4-DICHLOROPHENYL)-1,1-DIMETHYL-
- UROX D
- USAF P-7
- USAF XR-42
- VONDURON