Ethylene glycol monobutyl ether (EGBE) (2-Butoxyethanol) Quickview (CASRN 111-76-2)

Status of Data for Ethylene glycol monobutyl ether (EGBE) (2-Butoxyethanol)

File First On-Line: 12/30/1999; Last Significant Revision: 12/30/1999

Category (section)	Status	Last Revised
Oral RfD Assessment	On-line	12/30/1999
Inhalation RfC Assessment	On-line	12/30/1999
Carcinogenicity Assessment	On-line	12/30/1999
Under Re-Assessment

Synonyms

Ethylene glycol monobutyl ether (EGBE) CASRN -- 111-76-2 Last revised -- 12/30/1999

2-Butoxyethanol Ethylene glycol monobutyl ether (EGBE) (2-Butoxyethanol)

Chronic Health Hazard Assessments for Noncarcinogenic Effects

Reference Dose for Chronic Oral Exposure (RfD)

Critical Effect	Point of Departure*	UF	MF	RfD
Changes in mean corpuscular volume (MCV)	BMD5 (HED): 5.1 mg/kg-day	10	1	5 x10-1 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)
  • Subchronic (rat and mice) drinking water study, NTP, 1993
• Confidence in the Oral RfD
  • Study -- Medium
  • Database -- Medium/High
  • RfD -- Medium/High

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Reference Concentration for Chronic Inhalation Exposure (RfC)

Critical Effect	Point of Departure*	UF	MF	RfC
Changes in red blood cell (RBC) count	BMC5 (HEC): 380 mg/m3	30	1	1.3x101 mg/m3

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

• Principal and Supporting Studies (Inhalation RfC)
  • Subchronic rat inhalation study, NTP, 1998
• Confidence in the Inhalation RfC
  • Study -- High
  • Database -- Medium/High
  • RfC -- Medium/High

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Carcinogenicity Assessment for Lifetime Exposure

• Weight-of-Evidence Characterization
  • C (Possible human carcinogen)
  • Carcinogenic potential cannot be determined
• Weight-of-Evidence Narrative:
  • Because of the uncertain relevance of tumor increases observed in rats and mice to humans, the fact that EGBE is generally negative in genotoxic tests, and the lack of human data to support the findings in rodents, the human carcinogenic potential of EGBE, in accordance with the recently proposed Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1996), cannot be determined at this time, but suggestive evidence exists from rodent studies.
  • 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

• Information reviewed but value not estimated. See IRIS Summary.

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Quantitative Estimate of Carcinogenic Risk from Inhalation Exposure

• Information reviewed but value not estimated. See IRIS Summary.