IRIS

Chromium(VI)

CASRN 18540-29-9

Noncancer Assessment

Reference Dose for Oral Exposure (RfD) (PDF) (34 pp, 203 K) last updated: 09/03/1998

System RfD (mg/kg-day) Basis PoD Composite UF Confidence
None 3 x 10-3 None reported NOAEL (ADJ): 2.5
mg/kg-day
300
MF: 3
Low

 


Reference Concentration for Inhalation Exposure (RfC) (PDF) (34 pp, 203 K) last updated: 09/03/1998

System RfC (mg/m3) Basis PoD Composite UF Confidence
Respiratory 8 x 10-6
(Chromic acid mists and dissolved Cr(VI) aerosols)
Nasal septum atrophy LOAEL (ADJ): 7.14 x 10-4
mg/m3
90 Low
Respiratory 1 x 10-4
(Cr(VI) particulates)
Lactate dehydrogenase in bronchioalveolar lavage fluid BMC10 (ADJ): 3.4 x 10-2
mg/m3
300 Medium

 

Cancer Assessment

Weight of Evidence for Cancer (PDF) (34 pp, 203 K) last updated: 09/03/1998

WOE Characterization Framework for WOE Characterization
A (Human carcinogen) (Inhalation route) Guidelines for Carcinogen Risk Assessment (US EPA, 1986)
D (Not classifiable as to human carcinogenicity) (Oral route) Guidelines for Carcinogen Risk Assessment (US EPA, 1986)
Carcinogenic potential cannot be determined (Oral route) Proposed Guidelines for Carcinogen Risk Assessment (US EPA, 1996)
Known/likely human carcinogen (Inhalation route) Proposed Guidelines for Carcinogen Risk Assessment (US EPA, 1996)
Basis:
  • Under the current guidelines (EPA, 1986), Cr(VI) is classified as Group A - known human carcinogen by the inhalation route of exposure. Carcinogenicity by the oral route of exposure cannot be determined and is classified as Group D. Under the proposed guidelines (EPA, 1996), Cr(VI) would be characterized as a known human carcinogen by the inhalation route of exposure on the following basis. The oral carcinogenicity of Cr(VI) cannot be determined. No data were located in the available literature that suggested that Cr(VI) is carcinogenic by the oral route of exposure.
  • This may be a synopsis of the full weight-of-evidence narrative.

Quantitative Estimate of Carcinogenic Risk from Oral Exposure (PDF) (34 pp, 203 K)

Information reviewed but value not estimated.


Quantitative Estimate of Carcinogenic Risk from Inhalation Exposure (PDF) (34 pp, 203 K)

Inhalation Unit Risk: 1.2 x10 -2 per µg/m3
Extrapolation Method: Multistage, extra risk
Tumor site(s): Respiratory
Tumor type(s): Lung cancer (Mancuso, 1975)



Chromium(VI) is being reassessed.

Assessment Manager(s): Catherine Gibbons (gibbons.catherine@epa.gov), Alan Sasso (sasso.alan@epa.gov)

Step Assessment Materials Released to the Public Release Date Public Meeting Date
1 Problem Formulation Materials 04/2014 06/2014
1 Preliminary Assessment Materials 08/2014 10/2014
4 Public Comment Draft TBD TBD
4 Peer Review Draft TBD TBD
7 Post Final Assessment TBD

Please note: Any future dates displayed under Release Date are estimates and subject to change.

You will need Adobe Reader to view some of the files on this page. See EPA’s PDF page to learn more.

Quick Check