Tridiphane (CASRN 58138-08-2)
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0124
Tridiphane;
CASRN 58138-08-2
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 Tridiphane
File First On-Line 01/31/1987
Category (section) |
Status |
Last Revised |
---|---|---|
Oral RfD Assessment (I.A.) | on-line | 01/01/1992 |
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 — Tridiphane
CASRN — 58138-08-2
Last Revised — 01/01/1992
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 |
---|---|---|---|---|
Decreased fertility Rat, 2-Generation Dow Chemical, l984 |
NOEL: 0.33 mg/kg/day LEL: l.67 mg/kg/day |
100 |
1 |
3E-3 mg/kg/day |
*Dose Conversion Factors & Assumptions: none
__I.A.2. Principal and Supporting Studies (Oral RfD)
Dow Chemical. l984. MRID No. 00132088, 00145080; HED Doc. No. 003604,
004594. Available from EPA. Write to FOI, EPA, Washington D.C. 20460.
Rats (30/sex/group) were fed tridiphane at dose levels of 0, l, 5, or 30
mg/kg/day. Females were maintained on these diets throughout the study for
the production of Fla and Flb litters, and F2a and F2b litters. However,
starting with the F1b litters tridiphane concentrations in the diet were
adjusted downward so that lactating dams were receiving l/2 of the original
concentration between days 7-l4 of lactation, and l/3 of the original
concentration between days l4-28 of lactation. On day 28, the diets were
readjusted to the prelactation concentrations. Results of this study
indicated that tridiphane decreases the fertility index at the 5 and 30
mg/kg/day dose levels. Thus, the NOEL for reproductive effects was l
mg/kg/day. However, since the dose levels were adjusted downward by 67%, the
U.S. EPA established the NOEL as 0.33 mg/kg/day and the LEL as l.67 mg/kg/day.
__I.A.3. Uncertainty and Modifying Factors (Oral RfD)
UF — The standard UF of 100 was used for extrapolating from animal data to
humans accounting for intra- and inter-species variability.
MF — None
__I.A.4. Additional Studies/Comments (Oral RfD)
Other studies showed evidence that tridiphane caused liver toxicity.
Data Considered for Establishing the RfD
1) Two-Generation Reproduction - rat: Principal study - see discussion above;
core grade supplementary
2) Six-Month Feeding - dog: NOEL=l0 mg/kg/day; LEL=50 mg/kg/day
(hepatocellular hypotrophy; increased liver weight); Dose levels tested: 0,
l, l0, or 50 mg/kg/day; core grade guideline (Dow Chemical, 1982)
3) Teratology - mice: Teratogenic NOEL=250 mg/kg/day; Fetotoxic NOEL=75
mg/kg/day; LEL=250 mg/kg/day; Dose levels tested: 0, 25, 75, and 250
mg/kg/day; core grade minimum (Dow Chemical, 1978)
4) Teratology - rat: Teratogenic NOEL=200 mg/kg/day; Fetotoxic NOEL=30
mg/kg/day; LEL=l00 mg/kg/day; Dose levels tested: 0, 30, l00, and 200
mg/kg/day; core grade guideline (Dow Chemical, 1980)
5) Two-Year Feeding (Oncogenic) - rat: Systemic NOEL=3 mg/kg/day (M); LEL=30
mg/kg/day (M); Systemic NOEL=5 mg/kg/day (F); LEL=50 mg/kg/day F); Dose levels
tested: 0, 0.3, 3, and 30 mg/kg/day (Male); 0, 0.3, 5, and 50 mg/kg/day
(Female); core grade minimum (Dow Chemical, 1983)
Data Gap(s): None
__I.A.5. Confidence in the Oral RfD
Study — Medium
Database — High
RfD — High
The principal study is of good quality and is given a medium confidence rating. The database is of high quality and complete, thus, resulting in a high confidence rating. High confidence in the RfD follows.
__I.A.6. EPA Documentation and Review of the Oral RfD
Pesticide Registration Files/New Chemical
Agency Work Group Review — 04/22/1986
Verification Date — 04/22/1986
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 Tridiphane 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 — Tridiphane
CASRN — 58138-08-2
Not available at this time.
_II. Carcinogenicity Assessment for Lifetime Exposure
Substance Name — Tridiphane
CASRN — 58138-08-2
Not available at this time.
_III.
[reserved]
_IV. [reserved]
_V. [reserved]
_VI. Bibliography
Substance Name — Tridiphane
CASRN — 58138-08-2
Last Revised — 01/01/1992
_VI.A. Oral RfD References
Dow Chemical. l978. MRID No. 00132090; HED Doc. No. 003605. Available from
EPA. Write to FOI, EPA, Washington, DC 20460.
Dow Chemical. l980. MRID No. 00132089; HED Doc. No. 003605. Available from
EPA. Write to FOI, EPA, Washington, DC 20460.
Dow Chemical. l982. MRID No. 00132086, 00165619; HED Doc. No. 004593.
Available from EPA. Write to FOI, EPA, Washington, DC 20460.
Dow Chemical. l983. MRID No. 00128804, 00132087; HED Doc. No. 003604,
003605. Available from EPA. Write to FOI, EPA, Washington, DC 20460.
Dow Chemical. l984. MRID No. 00132088, 00145080; HED Doc. No. 003604,
004594. Available from EPA. Write to FOI, EPA, Washington, DC 20460.
_VI.B. Inhalation RfC References
None
_VI.C. Carcinogenicity Assessment References
None
_VII. Revision History
Substance Name — Tridiphane
CASRN — 58138-08-2
Date |
Section |
Description |
---|---|---|
09/30/1987 | All | CASRN added to file |
03/01/1988 | I.A.4. | Core grades added |
01/01/1992 | I.A.4. | Citations added |
01/01/1992 | 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. |
_VIII. Synonyms
Substance Name — Tridiphane
CASRN — 58138-08-2
Last Revised — 01/31/1987
- 58138-08-2
- DOWCO 356
- Tandem
- Tridiphane