Naled (CASRN 300-76-5)
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0175
Naled;
CASRN 300-76-5
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 Naled
File First On-Line 03/31/1987
Category (section) |
Status |
Last Revised |
---|---|---|
Oral RfD Assessment (I.A.) | on-line | 01/01/1995 |
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 — Naled
CASRN — 300-76-5
Last Revised — 01/01/1995
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.
NOTE: The Oral RfD for naled may change in the near future pending the
outcome of a further review now being conducted by the RfD/RfC Work Group.
__I.A.1. Oral RfD Summary
Critical Effect |
Experimental Doses* |
UF
|
MF
|
RfD |
---|---|---|---|---|
Brain ChE inhibition 2-Year Rat Study, Chevron Chemical Co., |
NOEL: 0.2 mg/kg/day LEL: 2.0 mg/kg/day |
100
|
1
|
2E-3
mg/kg/day |
*Conversion Factors: none
__I.A.2. Principal and Supporting Studies (Oral RfD)
Chevron Chemical Company. 1984a. MRID No. 00128701, 00141784, 40418901.
Available from EPA. Write to FOI, EPA, Washington, DC 20460.
Sprague-Dawley CD rats were randomly assigned to four groups (55 animals/
sex/group). The animals were fed (by gavage) diets containing 0, 0.2, 2, and
10 mg/kg/day for 2 years. Brain cholinesterase was inhibited approximately 24
and 60% in both male and female rats receiving dose levels of 2 and 10
mg/kg/day, respectively. Also there was a slight inhibition of red blood cell
cholinesterase and moderate inhibition of plasma cholinesterase at 10
mg/kg/day.
__I.A.3. Uncertainty and Modifying Factors (Oral RfD)
UF — An uncertainty factor of 100 was used to account for the fact that a
brain ChE NOEL was used in determining the RfD. This factor accounts for both
the expected inter- and intraspecies variability to the toxicity of this
chemical in lieu of specific data.
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: NOEL=0.2 mg/kg/day; LEL=2.0 mg/kg/day (inhibition of
plasma and RBC ChE, decreased hemoglobin and hematocriti); core grade minimum
(Chevron Chemical, 1986)
3) 2-Generation Reproduction - Rat: Parental NOEL=6 mg/kg/day; Parental
LEL=18 mg/kg/day (decreased body weight in males); Progeny NOEL=6 mg/kg/day;
Progeny LEL=18 mg/kg/day (decreased survival, litter size and pup body
weight); core grade minimum (Chevron Chemical, 1985)
4) Teratology - Rat: Maternal NOEL=10 mg/kg/day; Maternal LEL=40\mg/kg/day
(body weight loss, tremors, dyspnea, and depressed activity); Teratogenic
NOEL=40 mg/kg/day (HDT); Fetotoxic NOEL=40\mg/kg/day (HDT) (Chevron Chemical,
1984b)
5) Teratology - Rabbit: Maternal NOEL=8 mg/kg/day (HDT); Fetotoxic NOEL=8
mg/kg/day (HDT); core grade supplementary (Chevron Chemical, 1984c)
Other Data Reviewed:
1) 89-Week Feeding (oncogenic) - Mice: Systemic NOEL=15 mg/kg/day; Systemic
LEL=50-75 mg/kg/day (increased mortality, decreased body weight in males,
decreased relative liver weight in females); core grade minimum (Chevron
Chemical, 1984d)
Data Gap(s): Rabbit Teratology Study
__I.A.5. Confidence in the Oral RfD
Study — Medium
Database — Medium
RfD — Medium
The critical study is of fair quality and is given a medium rating. The data base has some gaps, but there is a good amount of chronic data in dogs and rodents; therefore, confidence in the database can be considered medium to high. Confidence in the RfD can also be considered medium to high.
__I.A.6. EPA Documentation and Review of the Oral RfD
Pesticide Registration Standard, December 1982
Pesticide Registration Files
Agency Work Group Review — 07/22/1986, 04/15/1987, 12/09/1994
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 Naled conducted in November 2001 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 — Naled
CASRN — 300-76-5
Not available at this time.
_II. Carcinogenicity Assessment for Lifetime Exposure
Substance Name — Naled
CASRN — 300-76-5
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 — Naled
CASRN — 300-76-5
Last Revised — 03/01/1991
_VI.A. Oral RfD References
Chevron Chemical Company. 1984a. MRID No. 00128701, 00141784, 40418901.
Available from EPA. Write to FOI, EPA, Washington, DC 20460.
Chevron Chemical Company. 1984b. MRID No. 00138682, 00144026. Available
from EPA. Write to FOI, EPA, Washington, DC 20460.
Chevron Chemical Company. 1984c. MRID No. 00146496. Available from EPA.
Write to FOI, EPA, Washington, DC 20460.
Chevron Chemical Company. 1984d. MRID No. 00141785, 00148569. Available
from EPA. Write to FOI, EPA, Washington, DC 20460.
Chevron Chemical Company. 1985. MRID No. 00146498. Available from EPA.
Write to FOI, EPA, Washington, DC 20460.
Chevron Chemical Company. 1986. MRID No. 00160751. 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 — Naled
CASRN — 300-76-5
Date |
Section |
Description |
---|---|---|
09/30/1987 | I.A.4. | Study description added (number 2.) |
09/30/1987 | IV. | Pesticide Registration Standard added |
06/01/1989 | I.A.6. | Work group review date added |
03/01/1991 | I.A.4. | Citations added |
03/01/1991 | VI. | Bibliography on-line |
01/01/1992 | IV. | Regulatory actions updated |
01/01/1995 | I.A. | Oral RfD noted as pending change |
01/01/1995 | I.A.6. | Work group review date added |
08/01/1995 | I.A., 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 — Naled
CASRN — 300-76-5
Last Revised — 03/31/1987
- 300-76-5
- Alvora
- Bromchlophos
- Bromex
- Bromex 50
- BRP
- Dibrom
- Dibromfos
- 1,2-Dibromo-2,2-dichloroethyldimethyl phosphate
- Dimethyl(1,2-dibromo-2,2-dichloroethyl)phosphate
- ENT 24988
- Fosbrom
- Naled
- Phosphoric acid, 1,2-dibromo-2,2-dichloroethyl dimethyl ester
- RE 4355