Jump to main content.


Nitrogen dioxide (CASRN 10102-44-0)

IRIS
List of IRIS Substances




view QuickView

Main Contents

Go

0080

Nitrogen dioxide; CASRN 10102-44-0

Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data, as outlined in the IRIS assessment development process. Sections I (Health Hazard Assessments for Noncarcinogenic Effects) and II (Carcinogenicity Assessment for Lifetime Exposure) present the conclusions that were reached during the assessment development process. Supporting information and explanations of the methods used to derive the values given in IRIS are provided in the guidance documents located on the IRIS website.

STATUS OF DATA FOR Nitrogen dioxide

File First On-Line 01/31/1987

Category (section)
Status
Last Revised
Oral RfD Assessment (I.A.) withdrawn 09/01/1994
Inhalation RfC Assessment (I.B.) message 02/01/1993
Carcinogenicity Assessment (II.) no data 10/01/1991

_I.  Chronic Health Hazard Assessments for Noncarcinogenic Effects

_I.A. Reference Dose for Chronic Oral Exposure (RfD)

Substance Name — Nitrogen dioxide
CASRN — 10102-44-0

The RfD for nitrogen dioxide has been withdrawn from IRIS as of 09/01/1994 based on the fact that nitrogen dioxide does not exist per se in water, since it reacts instantaneously with water to form nitric and nitrous acids (U.S. EPA, 1993).

In the presence of alkali (pH > 7.0), nitrates and nitrites are formed, respectively, from nitric and nitrous acids. RfDs presently exist for nitrates and nitrites. As more fully explained on the IRIS files for those chemicals, the critical effect is the formation of methemoglobin resulting from the oxidation of the ferrous iron (+2) in hemoglobin to ferric iron (+3). The inability of methemoglobin to combine with oxygen results in clinical effects due to tissue hypoxia.

U.S. EPA. 1993. Air Quality Criteria for Oxides of Nitrogen. Office of Health and Environmental Assessment, Environmental Criteria and Assessment Office, Research Triangle Park, NC. EPA-600/8-91/049aF.

Agency Work Group Review — 08/19/1985, 02/26/1986, 06/24/1992, 08/04/1994

EPA Contacts:

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).

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 nitrogen dioxide 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.

Top of page


_I.B. Reference Concentration for Chronic Inhalation Exposure (RfC)

Substance Name — Nitrogen dioxide
CASRN — 10102-44-0

An inhalation RfC will not be derived for nitrogen dioxide because a National Ambient Air Quality Standard (NAAQS) is available.

Agency Work Group Review — 09/19/1989

EPA Contacts:

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).

Top of page


_II.  Carcinogenicity Assessment for Lifetime Exposure

Substance Name — Nitrogen dioxide
CASRN — 10102-44-0

Not available at this time.

Top of page


_III.  [reserved]
_IV.  [reserved]
_V.  [reserved]


_VI.  Bibliography

Substance Name — Nitrogen dioxide
CASRN — 10102-44-0
Last Revised — 09/01/1994

_VI.A. Oral RfD References

U.S. EPA. 1993. Air Quality Criteria for Oxides of Nitrogen. Office of Health and Environmental Assessment, Environmental Criteria and Assessment Office, Research Triangle Park, NC. EPA-600/8-91/049aF.

Top of page


_VI.B. Inhalation RfC References

None

Top of page


_VI.C. Carcinogenicity Assessment References

None

Top of page


_VII.  Revision History

Substance Name — Nitrogen dioxide
CASRN — 10102-44-0

Date
Section
Description
03/31/1987 I.A.6. Documentation corrected
10/01/1989 I.B. Inhalation RfD now under review
08/01/1991 I.A. Oral RfD summary noted as pending change
10/01/1991 II. Carcinogenicity assessment now under review
01/01/1992 I.A.7. Primary contact changed
01/01/1992 IV. Regulatory actions updated
07/01/1992 I.A.2. Last paragraph deleted
07/01/1992 VI.A. Oral RfD references on-line
02/01/1993 I.B. No RfC in lieu of regulatory standard
09/01/1994 I.A. RfD withdrawn; replaced with permanent withdrawal msg
09/01/1994 VI.A. Oral RfD references revised
08/01/1995 II. 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.
10/28/2003 I.A. Screening-Level Literature Review Findings message has been added.

Top of page


_VIII.  Synonyms

Substance Name — Nitrogen dioxide
CASRN — 10102-44-0
Last Revised — 01/31/1987

Top of page

Recent Additions | Search IRIS | IRIS Home | NCEA Home | ORD Home


Jump to main content.