Dalapon, sodium salt (CASRN 75-99-0)
view QuickView

0146
Dalapon, sodium salt;
CASRN 75-99-0
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 Dalapon, sodium salt
File First On-Line 01/31/1987
Category (section) |
Status |
Last Revised |
---|---|---|
Oral RfD Assessment (I.A.) | on-line | 06/01/1989 |
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 — Dalapon, sodium salt
CASRN — 75-99-0
Last Revised — 06/01/1989
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
|
---|---|---|---|---|
Increased kidney 2-Year Rat Study Paynter et al., 1960 |
NOEL: 15 mg/kg/day LEL: 50 mg/kg/day |
300
|
1
|
3E-2
mg/kg/day |
*Conversion Factors: [15 or 50 mg/kg/day x 0.65 mg dalapon- Na/mg of com- mercial product x (143 g dalapon/165 g dalapon-Na)] = 8.45 or 28.17 mg/kg/day, respectively
__I.A.2. Principal and Supporting Studies (Oral RfD)
Paynter, O.E., T.W. Tusing, D.D. McCollister and V.K. Rowe. 1960. Toxicology
of Dalapon Sodium (2,2-dichloropropoionic acid, sodium salt). J. Agriculture
Food Chemicals. 8: 47-51.
Albino Carworth rats (24 male, 24 female/group) were fed diets providing 0, 5,
15, or 50 mg commerial dalapon sodium salt/kg bw/day for 2 years.
Hematological parameters were examined at timed intervals and histopathology
was performed at 104 weeks. A statistically significant (p<0.05) increase
over controls was observed in the kidney-to-body weight ratios of male rats
receiving 50 mg/kg/day. No differences from controls were observed. Kidney
lesions were not observed.
Paynter et al. (1960) reported that the commercial-grade dalapon sodium
contained 65% of the pure sodium salt of dalapon. The dose is further
adjusted to pure dalapon by multiplying by the ratio of the molecular weight
of dalapon (143) to its sodium salt (165).
__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
incomplete database on chronic toxicity.
MF — None
__I.A.4. Additional Studies/Comments (Oral RfD)
Although the database for Dalapon was judged not to be acceptable for OPP's
regulatory requirements by current standards, the existing database does
provide useful information to derive an RfD.
Data Considered for Establishing the RfD
1) 2-Year Feeding - rat: Principal study - see previous description; no core
grade (Paynter et al., 1960)
2) Teratology - rat: Maternal Toxicity NOEL=none; Maternal Toxicity LEL=500
mg/kg/day (LDT; decreased weight gain in all doses); Fetal Toxicity NOEL=none;
Fetal Toxicity LEL=500 mg/kg/day (LDT; decreased and delayed ossification of
sternebrae hyoids and sacral arches at all doses); No teratogenic reponses;
core grade supplementary (Dow Chemical, 1971)
3) 2-Year Feeding - dog: The Paynter et al. (1960) study is not considered
reliable.
4) Multi-generation Reproduction - rat: The Paynter et al. (1960) study is
not considered reliable.
Data Gap(s): Chronic Rat Feeding Study, Chronic Dog Feeding Study, Rat
Reproduction Study, Rat Teratology Study, Rabbit Teratology Study
__I.A.5. Confidence in the Oral RfD
Study — Low
Database — Low
RfD — Low
The critical study is given a low confidence rating for the following reasons: 1) Hematology was performed on only 3 males and 3 females, 2) clinical chemistry was not performed, 3) histology was performed on only half of the survivers at each dose, and 4) only a limited number of tissues were examined. Since there are extensive data gaps existing for dalapon, the data base is given a low confidence rating. 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, January 1987;
Pesticide Registration Files
Agency Work Group Review — 10/09/1985, 07/22/1986, 07/15/1987, 08/12/1987, 06/22/1988
Verification Date — 06/22/1988
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 Dalapon, sodium salt, 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).
_I.B. Reference Concentration for Chronic Inhalation Exposure (RfC)
Substance Name — Dalapon, sodium salt
CASRN — 75-99-0
Not available at this time.
_II. Carcinogenicity Assessment for Lifetime Exposure
Substance Name — Dalapon, sodium salt
CASRN — 75-99-0
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 — Dalapon, sodium salt
CASRN — 75-99-0
Last Revised — 02/01/1993
_VI.A. Oral RfD References
Dow Chemical Company. 1971. MRID No. 00082692. Available from EPA. Write
to FOI, EPA, Washington, DC 20460.
Paynter, O.E., T.W. Tusing, D.D. McCollister and V.K. Rowe. 1960. Toxicology
of Dalapon Sodium (2,2-dichloropropoionic acid, sodium salt). J. Agriculture
Food Chemicals. 8: 47-51.
_VI.B. Inhalation RfC References
None
_VI.C. Carcinogenicity Assessment References
None
_VII. Revision History
Substance Name — Dalapon, sodium salt
CASRN — 75-99-0
Date |
Section |
Description |
---|---|---|
09/30/1987 | All | CASRN changed |
08/22/1988 | I.A. | Oral RfD summary replaced - RfD changed |
12/01/1988 | I.A.4. | Study description deleted |
06/01/1989 | I.A.6. | Work group review date added |
01/01/1990 | VI. | Bibliography on-line |
01/01/1992 | IV. | Regulatory actions updated |
02/01/1993 | III.A. | Health Advisory on-line |
02/01/1993 | VI.D. | Health Advisory references on-line |
08/01/1995 | I.A.6 | EPA's RfD/RfC and CRAVE workgroups were discontinued in May, 1995. Chemical substance reviews that were not completed by September 1995 were taken out of IRIS review. The IRIS Pilot Program replaced the workgroup functions beginning in September, 1995. |
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 — Dalapon, sodium salt
CASRN — 75-99-0
Last Revised — 01/31/1987
- 75-99-0
- basfapon B
- CASRN 127-20-8
- dalapon
- dalapon sodium
- Dalapon, sodium salt
- 2,2-dichloropropionic acid
- alpha-alpha-dichloropropionic acid
- 2,2-dichlorpropionsaeure natrium
- Dowpon
- 2,2-DPA
- gramevin
- propionic acid, 2,2-dichloro-
- radapon
- sodium dalapon
- sodium 2,2-dichloropropionate
- sodium alpha,alpha-dichloropropionate
- unipon