Barium and Compounds Quickview (CASRN 7440-39-3)

Status of Data for Barium and Compounds

File First On-Line: 01/31/1987; Last Significant Revision: 07/11/2005

Category (section)	Status	Last Revised
Oral RfD Assessment	On-line	07/11/2005
Inhalation RfC Assessment	On-line	03/30/1998
Carcinogenicity Assessment	On-line	03/30/1998

Synonyms

7440-39-3 Barium UN 1399

UN 1400 UN 1854 Barium and Compounds

Chronic Health Hazard Assessments for Noncarcinogenic Effects

Reference Dose for Chronic Oral Exposure (RfD)

Critical Effect	Point of Departure*	UF	MF	RfD
Nephropathy	BMDL05 : 63 mg/kg-day	300	1	0.2 mg/kg-day

* The Point of Departure listed serves as a basis from which the Oral RfD was derived. See Discussion of Conversion Factors and Assumptions for more details.

• Principal and Supporting Studies (Oral RfD)
  • 2-year drinking water study in mice, NTP (1994)
• Confidence in the Oral RfD
  • Study -- High
  • Database -- Medium
  • RfD -- Medium

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Reference Concentration for Chronic Inhalation Exposure (RfC)

Information reviewed but value not estimated. See IRIS Summary.

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Carcinogenicity Assessment for Lifetime Exposure

• Weight-of-Evidence Characterization
  • D (Not classifiable as to human carcinogenicity)
  • Carcinogenic potential cannot be determined (Inhalation route)
  • Not likely to be carcinogenic to humans (Oral route)
• Weight-of-Evidence Narrative:
  • Under EPA's 1986 Guidelines for Carcinogen Risk Assessment, barium would be classified as Group D, not classifiable as to human carcinogenicity. Under the Proposed Guidelines for Carcinogenic Risk Assessment (U.S. EPA, 1996), barium is considered not likely to be carcinogenic to humans following oral exposure and its carcinogenic potential cannot be determined following inhalation exposure.
  • This may be a synopsis of the full weight-of-evidence narrative. See IRIS Summary.

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Quantitative Estimate of Carcinogenic Risk from Oral Exposure

• Not Assessed under the IRIS Program.

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Quantitative Estimate of Carcinogenic Risk from Inhalation Exposure

• Not Assessed under the IRIS Program.