Maleic hydrazide (CASRN 123-33-1)
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0172
Maleic hydrazide;
CASRN 123-33-1
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 Maleic hydrazide
File First On-Line 03/31/1987
Category (section) |
Status |
Last Revised |
---|---|---|
Oral RfD Assessment (I.A.) | on-line | 05/01/1992 |
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 — Maleic hydrazide
CASRN — 123-33-1
Last Revised — 05/01/1992
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
|
---|---|---|---|---|
Renal dysfunction 2-Year Rat Feeding Uniroyal Chemical Co. |
NOEL: none LEL: 1% of diet |
1000
|
1
|
5E-1
mg/kg/day |
*Conversion Factors and Assumptions — 1 ppm = 0.05 mg/kg/day (assumed rat food consumption)
__I.A.2. Principal and Supporting Studies (Oral RfD)
Uniroyal Chemical Co. 1981. Acc. No. 250523. Available from EPA. Write to FOI, EPA, Washington, DC 20460.
Twenty-five male and 50 female SPF Wistar rats were fed 0, 1 or 2% maleic hydrazide (MH) in their diet during the 1-week premating period and the 1-week mating period. At weaning, F1 offspring males and females were taken at random from the three experimental groups for the 28-month carcinogenicity study. The same levels of MH were administered in the diet. Group 1 consisted of 65 female and 65 male rats (2%); group 2 consisted of 55 animals from each sex (1%); and group 3 consisted of 55 control animals (diet only) from each sex. Observations included renal dysfunction.
__I.A.3. Uncertainty and Modifying Factors (Oral RfD)
UF — An uncertainty factor of 1000 was used to account for the inter- and intraspecies differences and to account for the fact that a LEL was used as a basis for the RfD instead of a NOEL.
MF — None
__I.A.4. Additional Studies/Comments (Oral RfD)
Data Considered for Establishing the RfD:
1) 2-Year Feeding - Rat: Principal study - see previous description; core grade minimum 2) Teratolgy - Rabbit: NOEL=100 mg/kg/day; LEL=300\mg/kg/day; (malformed scapulae); core grade minimum (Uniroyal Chemical Co., 1983a) 3) 2-Generation Reproduction - Rat: NOEL=500 mg/kg/day; LEL=1500\mg/kg/day; (postnatal decrease in body weight); core grade minimum (Uniroyal Chemical Co., 1983b) 4) 1-Year Feeding - Dog: NOEL=600 mg/kg/day (HDT); no core grade (Uniroyal Chemical Co., 1954)
Data Gap(s): Chronic Feeding Dog Study; Rat Teratology Study
__I.A.5. Confidence in the Oral RfD
Study — Low
Database — Medium
RfD — Medium
The critical study appears to be of low to medium quality and is given a low confidence rating. The database is given medium confidence since it is incomplete. Medium confidence in the RfD follows.
__I.A.6. EPA Documentation and Review of the Oral RfD
Pesticide Registration Files
Agency Work Group Review — 07/22/1986
Verification Date — 07/22/1986
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 Maleic hydrazide conducted in September 2002 identified one or more significant new studies. IRIS users may request the references for those studies from 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 — Maleic hydrazide
CASRN — 123-33-1
Not available at this time.
_II. Carcinogenicity Assessment for Lifetime Exposure
Substance Name — Maleic hydrazide
CASRN — 123-33-1
Not available at this time.
_III.
[reserved]
_IV. [reserved]
_V. [reserved]
_VI. Bibliography
Substance Name — Maleic hydrazide
CASRN — 123-33-1
Last Revised — 05/01/1992
_VI.A. Oral RfD References
Uniroyal Chemical Co. 1981. Acc. No. 250523. Available from EPA. Write to FOI, EPA, Washington, DC 20460.
Uniroyal Chemical Co. 1954. MRID No. 00112753; HED Doc. No. 004757. Available from EPA. Write to FOI, EPA, Washington, DC 20460.
Uniroyal Chemical Company. 1983a. MRID No. 00128721; HED Doc. No. 004330. Available from EPA. Write to FOI, EPA, Washington, DC 20460.
Uniroyal Chemical Co. 1983b. MRID No. 00141358, 00128720; HED Doc. No. 004330. 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 — Maleic hydrazide
CASRN — 123-33-1
Date |
Section |
Description |
---|---|---|
03/01/1988 | I.A.5. | Confidence levels revised |
01/01/1992 | IV. | Regulatory actions updated |
05/01/1992 | I.A.7. | Primary contact changed |
05/01/1992 | VI.A. | 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. |
_VIII. Synonyms
Substance Name — Maleic hydrazide
CASRN — 123-33-1
Last Revised — 03/31/1987
- 123-33-1
- BURTOLIN
- CHEMFORM
- DE-CUT
- DE-SPROUT
- 1,2-DIHYDRO-3,6-PYRADIZINEDIONE
- 1,2-DIHYDROPYRIDAZINE-3,6-DIONE
- DREXEL-SUPER P
- ENT 18,870
- FAIR 30
- FAIR PS
- 6-HYDROXY-3(2H)-PYRIDAZINONE
- KMH
- MAH
- MAINTAIN 3
- MALAZIDE
- MALEIC ACID HYDRAZIDE
- Maleic Hydrazide
- MALEIC HYDRAZIDE 30%
- MALEIC HYDRAZINE
- MALEIN 30
- MALEINSAEUREHYDRAZID
- MH
- MH 30
- MH 36 BAYER
- MH-40
- N,N-MALEOYLHYDRAZINE
- 3,6-PYRIDAZINEDIONE, 1,2-DIHYDRO-
- RCRA WASTE NUMBER U148
- REGULOX
- REGULOX 50 W
- REGULOX W
- RETARD
- ROYAL MH-30
- ROYAL SLO-GRO
- SLO-GRO
- SPROUT/OFF
- SPROUT-STOP
- STUNTMAN
- SUCKER-STUFF
- SUPER-DE-SPROUT
- SUPER SPROUT STOP
- SUPER SUCKER-STUFF
- 1,2,3,6-TETRAHYDRO-3,6-DIOXOPYRIDAZINE
- VONDALHYDE
- VONDRAX