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CAS Number: 74-86-2
SMILES : C#C
CHEM : Ethyne
MOL FOR: C2 H2
MOL WT : 26.04
------------------------------ EPI SUMMARY (v4.11) --------------------------
Physical Property Inputs:
Log Kow (octanol-water): ------
Boiling Point (deg C) : ------
Melting Point (deg C) : ------
Vapor Pressure (mm Hg) : ------
Water Solubility (mg/L): ------
Henry LC (atm-m3/mole) : ------
Log Octanol-Water Partition Coef (SRC):
Log Kow (KOWWIN v1.68 estimate) = 0.50
Log Kow (Exper. database match) = 0.37
Exper. Ref: HANSCH,C ET AL. (1995)
Boiling Pt, Melting Pt, Vapor Pressure Estimations (MPBPVP v1.43):
Boiling Pt (deg C): -36.63 (Adapted Stein & Brown method)
Melting Pt (deg C): -154.04 (Mean or Weighted MP)
VP(mm Hg,25 deg C): 1.81E+004 (Mean VP of Antoine & Grain methods)
VP (Pa, 25 deg C) : 2.42E+006 (Mean VP of Antoine & Grain methods)
MP (exp database): -80.7 deg C
BP (exp database): -84.7 deg C
VP (exp database): 3.65E+04 mm Hg (4.87E+006 Pa) at 25 deg C
Water Solubility Estimate from Log Kow (WSKOW v1.42):
Water Solubility at 25 deg C (mg/L): 1.476e+004
log Kow used: 0.37 (expkow database)
no-melting pt equation used
Water Sol (Exper. database match) = 1200 mg/L (20 deg C)
Exper. Ref: YALKOWSKY,SH & HE,Y (2003)
Water Sol Estimate from Fragments:
Wat Sol (v1.01 est) = 12559 mg/L
ECOSAR Class Program (ECOSAR v1.11):
Class(es) found:
Neutral Organics
Henrys Law Constant (25 deg C) [HENRYWIN v3.20]:
Bond Method : 2.40E-002 atm-m3/mole (2.43E+003 Pa-m3/mole)
Group Method: 2.45E-002 atm-m3/mole (2.48E+003 Pa-m3/mole)
Exper Database: 2.17E-02 atm-m3/mole (2.20E+003 Pa-m3/mole)
For Henry LC Comparison Purposes:
User-Entered Henry LC: not entered
Henrys LC [via VP/WSol estimate using User-Entered or Estimated values]:
HLC: 1.764E-003 atm-m3/mole (1.788E+002 Pa-m3/mole)
VP: 1.81E+004 mm Hg (source: MPBPVP)
WS: 1.48E+004 mg/L (source: WSKOWWIN)
Log Octanol-Air Partition Coefficient (25 deg C) [KOAWIN v1.10]:
Log Kow used: 0.37 (exp database)
Log Kaw used: -0.052 (exp database)
Log Koa (KOAWIN v1.10 estimate): 0.422
Log Koa (experimental database): None
Probability of Rapid Biodegradation (BIOWIN v4.10):
Biowin1 (Linear Model) : 0.7351
Biowin2 (Non-Linear Model) : 0.9333
Expert Survey Biodegradation Results:
Biowin3 (Ultimate Survey Model): 3.1416 (weeks )
Biowin4 (Primary Survey Model) : 3.8102 (days )
MITI Biodegradation Probability:
Biowin5 (MITI Linear Model) : 0.6347
Biowin6 (MITI Non-Linear Model): 0.8550
Anaerobic Biodegradation Probability:
Biowin7 (Anaerobic Linear Model): 0.8361
Ready Biodegradability Prediction: YES
Hydrocarbon Biodegradation (BioHCwin v1.01):
LOG BioHC Half-Life (days) : 0.4898
BioHC Half-Life (days) : 3.0886
Sorption to aerosols (25 Dec C)[AEROWIN v1.00]:
Vapor pressure (liquid/subcooled): 4.87E+006 Pa (3.65E+004 mm Hg)
Log Koa (Koawin est ): 0.422
Kp (particle/gas partition coef. (m3/ug)):
Mackay model : 6.16E-013
Octanol/air (Koa) model: 6.49E-013
Fraction sorbed to airborne particulates (phi):
Junge-Pankow model : 2.23E-011
Mackay model : 4.93E-011
Octanol/air (Koa) model: 5.19E-011
Atmospheric Oxidation (25 deg C) [AopWin v1.92]:
Hydroxyl Radicals Reaction:
OVERALL OH Rate Constant = 0.8150 E-12 cm3/molecule-sec
Half-Life = 13.124 Days (12-hr day; 1.5E6 OH/cm3)
Ozone Reaction:
OVERALL Ozone Rate Constant = 0.003000 E-17 cm3/molecule-sec
Half-Life = 382.000 Days (at 7E11 mol/cm3)
Fraction sorbed to airborne particulates (phi):
3.58E-011 (Junge-Pankow, Mackay avg)
5.19E-011 (Koa method)
Note: the sorbed fraction may be resistant to atmospheric oxidation
Soil Adsorption Coefficient (KOCWIN v2.00):
Koc : 13.22 L/kg (MCI method)
Log Koc: 1.121 (MCI method)
Koc : 2.093 L/kg (Kow method)
Log Koc: 0.321 (Kow method)
Aqueous Base/Acid-Catalyzed Hydrolysis (25 deg C) [HYDROWIN v2.00]:
Rate constants can NOT be estimated for this structure!
Bioaccumulation Estimates (BCFBAF v3.01):
Log BCF from regression-based method = 0.500 (BCF = 3.162 L/kg wet-wt)
Log Biotransformation Half-life (HL) = -1.4901 days (HL = 0.03235 days)
Log BCF Arnot-Gobas method (upper trophic) = 0.014 (BCF = 1.033)
Log BAF Arnot-Gobas method (upper trophic) = 0.014 (BAF = 1.033)
log Kow used: 0.37 (expkow database)
Volatilization from Water:
Henry LC: 0.0217 atm-m3/mole (Henry experimental database)
Half-Life from Model River: 0.5345 hours (32.07 min)
Half-Life from Model Lake : 48.62 hours (2.026 days)
Removal In Wastewater Treatment:
Total removal: 89.42 percent
Total biodegradation: 0.03 percent
Total sludge adsorption: 0.41 percent
Total to Air: 88.98 percent
(using 10000 hr Bio P,A,S)
Level III Fugacity Model:
Mass Amount Half-Life Emissions
(percent) (hr) (kg/hr)
Air 50.4 298 1000
Water 47.2 360 1000
Soil 2.26 720 1000
Sediment 0.113 3.24e+003 0
Persistence Time: 131 hr