Cyanide, free Quickview (CASRN 57-12-5)

Status of Data for Cyanide, free

File First On-Line: 01/31/1987; Last Significant Revision: 09/07/1988

Category (section)	Status	Last Revised
Oral RfD Assessment	On-line	02/01/1993
Inhalation RfC Assessment	No data
Carcinogenicity Assessment	On-line	03/01/1991

Synonyms

57-12-5 Carbon nitride ion Cyanide ion Cyanure Free cyanide

RCRA Waste Number p030 Cyanide Cyanide, free Isocyanide Cyanide anion

Chronic Health Hazard Assessments for Noncarcinogenic Effects

Reference Dose for Chronic Oral Exposure (RfD)

Critical Effect	Point of Departure*	UF	MF	RfD
No adverse effects (other effect: Weight loss, thyroid effects and myelin degeneration. )	NOAEL : 10.8 mg/kg-day	100	5	2 x10-2 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)
  • Rat chronic oral study, Howard and Hanzal, 1955
• Confidence in the Oral RfD
  • Study -- Medium
  • Database -- Medium
  • RfD -- Medium

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Reference Concentration for Chronic Inhalation Exposure (RfC)

Not Assessed under the IRIS Program.

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Carcinogenicity Assessment for Lifetime Exposure

• Weight-of-Evidence Characterization
  • D (Not classifiable as to human carcinogenicity)
• Weight-of-Evidence Narrative:
  • Pertinent data regarding carcinogenicity have not been located in the available literature.
  • 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.