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1 Cyanide Salts Acute Exposure Guideline Levels
Pages 13-40

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From page 13...
... Both the document and the AEGL values were then reviewed by the National Research Council (NRC) Committee on Acute Exposure Guideline Levels.
From page 14...
... Although the AEGL values represent threshold concentrations for the general public, including susceptible subpopulations, such as infants, children, the elderly, persons with asthma, and those with other illnesses, it is recognized that individuals, subject to idiosyncratic responses, could experience the effects described at concentrations below the corresponding AEGL. SUMMARY Sodium cyanide, potassium cyanide, and calcium cyanide are simple inorganic cyanide salts with an almond-like odor.
From page 15...
... . TABLE 1-1 AEGL Values for Cyanide Saltsa Classification 10 min 30 min 1h 4h 8h Sodium Cyanide AEGL-1 5.0 mg/m3 5.0 mg/m3 4.0 mg/m3 2.6 mg/m3 2.0 mg/m3 AEGL-2 34 mg/m3 20 mg/m3 14 mg/m3 7.0 mg/m3 5.0 mg/m3 AEGL-3 54 mg/m3 42 mg/m3 30 mg/m3 17 mg/m3 13 mg/m3 Potassium Cyanide AEGL-1 6.6 mg/m3 6.6 mg/m3 5.3 mg/m3 3.5 mg/m3 2.7 mg/m3 AEGL-2 45 mg/m3 27 mg/m3 19 mg/m3 9.3 mg/m3 6.6 mg/m3 AEGL-3 72 mg/m3 56 mg/m3 40 mg/m3 23 mg/m3 18 mg/m3 b Calcium Cyanide AEGL-1 4.7 mg/m3 4.7 mg/m3 3.8 mg/m3 2.4 mg/m3 1.9 mg/m3 AEGL-2 32 mg/m3 19 mg/m3 13 mg/m3 6.6 mg/m3 4.7 mg/m3 AEGL-3 51 mg/m3 39 mg/m3 28 mg/m3 16 mg/m3 12 mg/m3 a Airborne concentrations of these salts will produce the equivalent AEGL values for hydrogen cyanide.
From page 16...
... . One mole of sodium cyanide or potassium cyanide may react with water or moisture to produce a maximum of one mole of hydrogen cyanide by the following reactions: NaCN + H2O → HCN + NaOH KCN+ H2O → HCN + KOH One mole of calcium cyanide may react with water or moisture to produce a maximum of two moles of hydrogen cyanide by the following reaction: Ca(CN)
From page 17...
... TABLE 1-2 Chemical and Physical Properties of Sodium Cyanide Parameter Value References Synonyms Cyanogran; cyanide of sodium; cymag; hydrocyanic Kopras 2012 acid sodium salt; cyanobrik; white cyanide CAS registry no. 143-33-9 HSDB 2005a Chemical formula NaCN HSDB 2005a Molecular weight 49.0 HSDB 2005a Physical state White crystalline solid HSDB 2005a Melting point 563°C HSDB 2005a Boiling point 1,496°C HSDB 2005a 3 Density /specific gravity 1.595 g/cm at 20°C HSDB 2005a Solubility in water 48 g/100 mL water at 10°C; forms HCN HSDB 2005a Vapor pressure 1 mm Hg at 817°C HSDB 2005a -5 Hydrolysis constant 2.51 × 10 per second at 25°C; yields calculated Pesce 2010 half-life of 7.7 h Conversion factors 1 ppm = 2.0 mg/m3 1 mg/m3 = 0.50 ppm TABLE 1-3 Chemical and Physical Properties of Potassium Cyanide Parameter Value References Synonyms Hydrocyanic acid potassium salt Kopras 2012 CAS registry no.
From page 18...
... Dermal exposure to cyanide salts in solution, or exposure of moist or abraded skin to dry cyanide salts, can result in significant absorption of cyanide ion or hydrogen cyanide (Ballantyne 1987)
From page 19...
... that the cyanide moiety is responsible for the acute toxicity of the cyanide salts. Cyanide-induced clinical effects are indistinguishable in humans and animals after inhalation or dermal exposure to hydrogen cyanide vapor or after oral exposure to sodium or potassium cyanide.
From page 20...
... In addition, because hydrolysis of cyanide salts in the air or moist respiratory tract may be incomplete (whereas hydrolysis is likely complete after oral exposure due to the low pH of the stomach) , the use of hydrogen cyanide as a surrogate for derivation of AEGL values is expected to be conservative.
From page 21...
... In addition, because hydrolysis of cyanide salts in the air or moist respiratory tract may be incomplete (whereas hydrolysis is likely complete after oral exposure due to the low pH of the stomach) , the use of hydrogen cyanide as a surrogate for derivation of AEGL values is expected to be conservative.
From page 22...
... TABLE 1-7 AEGL-2 Values for Cyanide Saltsa Compound 10 min 30 min 1h 4h 8h Sodium cyanide 34 mg/m3 20 mg/m3 14 mg/m3 7.0 mg/m3 5.0 mg/m3 Potassium cyanide 45 mg/m3 27 mg/m3 19 mg/m3 9.3 mg/m3 6.6 mg/m3 Calcium cyanideb 32 mg/m3 19 mg/m3 13 mg/m3 6.6 mg/m3 4.7 mg/m3 a Airborne concentrations of these salts will produce the equivalent AEGL values for hydrogen cyanide. b Although the adjusted rat oral LD50 value for calcium cyanide is much greater than would be expected on a molar basis for cyanide (suggesting that it is a less toxic compound)
From page 23...
... immediately dangerous to life or health value of 25 mg/m3. TABLE 1-8 AEGL-3 Values for Cyanide Saltsa Compound 10 min 30 min 1h 4h 8h Sodium cyanide 54 mg/m3 42 mg/m3 30 mg/m3 17 mg/m3 13 mg/m3 Potassium cyanide 72 mg/m3 56 mg/m3 40 mg/m3 23 mg/m3 18 mg/m3 b 3 3 3 3 Calcium cyanide 51 mg/m 39 mg/m 28 mg/m 16 mg/m 12 mg/m3 a Airborne concentrations of these salts will produce the equivalent AEGL values for hydrogen cyanide.
From page 24...
... TABLE 1-10 Standards and Guidelines for Cyanide Salts (Expressed as CN-) Exposure Duration Guideline 10 min 30 min 1h 4h 8h AEGL-1 2.7 mg/m3 2.7 mg/m3 2.1 mg/m3 1.3 mg/m3 1.1 mg/m3 AEGL-2 18 mg/m3 11 mg/m3 7.5 mg/m3 3.8 mg/m3 2.7 mg/m3 3 3 3 3 AEGL-3 29 mg/m 22 mg/m 16 mg/m 9.1 mg/m 7.0 mg/m3 IDLH (NIOSH)
From page 25...
... 2001. Documen tation of the Threshold Limit Values and Biological Exposure Indices: Hydrogen Cyanide and Cyanide Salts, as CN.
From page 26...
... 2014. Calcium Cyanide (CASRN 592-01-8)
From page 27...
... Occupational Exposure to Hydrogen Cya nide and Cyanide Salts (NaCN, KCN, and Ca(CN2)
From page 28...
... . Sodium Cyanide 10-min AEGL-1: 2.5 ppm ÷ 1 = 2.5 ppm 2.5 ppm × 49.0 ÷ 24.5 = 5.0 mg/m3 30-min AEGL-1: 2.5 ppm ÷ 1 = 2.5 ppm 2.5 ppm × 49.0 ÷ 24.5 = 5.0 mg/m3 1-h AEGL-1: 2.0 ppm ÷ 1 = 2.0 ppm 2.0 ppm × 49.0 ÷ 24.5 = 4.0 mg/m3 4-h AEGL-1: 1.3 ppm ÷ 1 = 1.3 ppm 1.3 ppm × 49.0 ÷ 24.5 = 2.6 mg/m3 8-h AEGL-1: 1.0 ppm ÷ 1 = 1.0 ppm 1.0 ppm × 49.0 ÷ 24.5 = 2.0 mg/m3 Potassium Cyanide 10-min AEGL-1: 2.5 ppm ÷ 1 = 2.5 ppm 2.5 ppm × 65.1 ÷ 24.5 = 6.6 mg/m3 30-min AEGL-1: 2.5 ppm ÷ 1 = 2.5 ppm 2.5 ppm × 65.1 ÷ 24.5 = 6.6 mg/m3 1-h AEGL-1: 2.0 ppm ÷ 1 = 2.0 ppm 2.0 ppm × 65.1 ÷ 24.5 = 5.3 mg/m3 4-h AEGL-1: 1.3 ppm ÷ 1 = 1.3 ppm 1.3 ppm × 65.1 ÷ 24.5 = 3.5 mg/m3 8-h AEGL-1: 1.0 ppm ÷ 1 = 1.0 ppm 1.0 ppm × 65.1 ÷ 24.5 = 2.7 mg/m3
From page 29...
... . Sodium Cyanide 10-min AEGL-2: 17 ppm ÷ 1 = 17 ppm 17 ppm × 49.0 ÷ 24.5 = 34 mg/m3 30-min AEGL-2: 10 ppm ÷ 1 = 10 ppm 10 ppm × 49.0 ÷ 24.5 = 20 mg/m3 1-h AEGL-2: 7.1 ppm ÷ 1 = 7.1 ppm 7.1 ppm × 49.0 ÷ 24.5 = 14 mg/m3 4-h AEGL-2: 3.5 ppm ÷ 1 = 3.5 ppm 3.5 ppm × 49.0 ÷ 24.5 = 7.0 mg/m3 8-h AEGL-2: 2.5 ppm ÷ 1 = 2.5 ppm 2.5 ppm × 49.0 ÷ 24.5 = 5.0 mg/m3 Potassium Cyanide 10-min AEGL-2: 17 ppm ÷ 1 = 17 ppm 17 ppm × 65.1 ÷ 24.5 = 45 mg/m3
From page 30...
... . Sodium Cyanide 10-min AEGL-3: 27 ppm ÷ 1 = 27 ppm 27 ppm × 49.0 ÷ 24.5 = 54 mg/m3 30-min AEGL-3: 21 ppm ÷ 1 = 21 ppm 21 ppm × 49.0 ÷ 24.5 = 42 mg/m3 1-h AEGL-3: 15 ppm ÷ 1 = 15 ppm 15 ppm × 49.0 ÷ 24.5 = 30 mg/m3
From page 31...
... Cyanide Salts 31 4-h AEGL-3: 8.6 ppm ÷ 1 = 8.6 ppm 8.6 ppm × 49.0 ÷ 24.5 = 17 mg/m3 8-h AEGL-3: 6.6 ppm ÷ 1 = 6.6 ppm 6.6 ppm × 49.0 ÷ 24.5 = 13 mg/m3 Potassium Cyanide 10-min AEGL-3: 27 ppm ÷ 1 = 27 ppm 27 ppm × 65.1 ÷ 24.5 = 72 mg/m3 30-min AEGL-3: 21 ppm ÷ 1 = 21 ppm 21 ppm × 65.1 ÷ 24.5 = 56 mg/m3 1-h AEGL-3: 15 ppm ÷ 1 = 15 ppm 15 ppm × 65.1 ÷ 24.5 = 40 mg/m3 4-h AEGL-3: 8.6 ppm ÷ 1 = 8.6 ppm 8.6 ppm × 65.1 ÷ 24.5 = 23 mg/m3 8-h AEGL-3: 6.6 ppm ÷ 1 = 6.6 ppm 6.6 ppm × 65.1 ÷ 24.5 = 18 mg/m3 Calcium Cyanide 10-min AEGL-3: 27 ppm ÷ 2 = 13.5 ppm 13.5 ppm × 92.1 ÷ 24.5 = 51 mg/m3 30-min AEGL-3: 21 ppm ÷ 2 = 10.5 ppm 10.5 ppm × 92.1 ÷ 24.5 = 39 mg/m3 1-h AEGL-3: 15 ppm ÷ 2 = 7.5 ppm 7.5 ppm × 92.1 ÷ 24.5 = 28 mg/m3 4-h AEGL-3: 8.6 ppm ÷ 2 = 4.3 ppm 4.3 ppm × 92.1 ÷ 24.5 = 16 mg/m3 8-h AEGL-3: 6.6 ppm ÷ 2 = 3.3 ppm 3.3 ppm × 92.1 ÷ 24.5 = 12 mg/m3
From page 32...
... A factor of 3 for intraspecies differences was applied to the supporting studies because no susceptible populations were identified. The uncertainty factor was applied to the 8-h 5 ppm and 8 ppm concentrations, which resulted in concentrations close to the 8-h 1-ppm concentration in the Leeser et al.
From page 33...
... ½ = 3.5 ppm 8-h AEGL-2: (3,000 ppm-min ÷ 480 min) ½ = 2.5 ppm Derivation of AEGL-3 Values Key study: Haskell Laboratory 1981 Toxicity end point: 15-min LC01 of 138 ppm in the rat 30-min LC01 of 127 ppm in the rat 1-h LC01 of 88 ppm in the rat LC01 derived by probit analysis Time scaling: C2.6 × t = k (this document; based on the Haskell Laboratory [1981]
From page 34...
... 34 Acute Exposure Guideline Levels Calculations: (C2.6 ÷ uncertainty factors)
From page 35...
... data suggest that the cyanide moiety is responsible for the acute toxicity of the cyanide salts. The hydrogen cyanide AEGL-1 values were used as target values for calculating the concentrations of cyanide salt needed to generate the hydrogen cyanide AEGL values.
From page 36...
... data suggest that the cyanide moiety is responsible for acute toxicity of the cyanide salts. The hydrogen cyanide AEGL-3 values were used as target values for calculating the concentrations of cyanide salt needed to generate the hydrogen cyanide AEGL values.
From page 37...
... 1990. A Cross-sectional Study of the Health of Cyanide Salt Production Workers.
From page 38...
... A factor of 3 was applied to the supporting studies as no specific susceptible populations were identified in monitoring studies or during the clinical use of nitroprusside solutions to control hypertension. The detoxifying enzyme rhodanese is present in all individuals including newborns.
From page 39...
... Intraspecies: 3–No specific susceptible populations were identified during monitoring studies or during the clinical use of nitroprusside solutions to control hypertension. The detoxifying enzyme rhodanese is present in all individuals including newborns.
From page 40...
... The mechanism is the same for all species. Intraspecies: 3 - No specific susceptible populations were identified during monitoring studies or during the clinical use of nitroprusside solutions to control hypertension.


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