FACTSHEET: QSAR System
Using a database of 23,000 chemicals, QSAR utilizes the Quantitative Structural
Activity Relationships method to:
- Estimate environmental properties
- Predict environmental fate
- Evaluate new chemicals
The 11 key properties and parameters that can be calculated are:
| log P | Heat of Vaporization | Boiling Point
|
| Acid Dissociation Constant | Vapor Pressure | Parachor
|
| Molecular Weight | Molar Volume | Water Solubility
|
| Molar Refraction | Melting Point
|
Further options that are available to the user after a property has been calculated
are:
- Obtain the details of the estimation method
- Change a value for use in subsequent estimations
Additional information can be obtained for:
- Henry's Law Constant and environmental partitioning patterns (air, water,
ground and hydrosoil).
- Aquatic Toxicity Estimates (LC50 in 7 common test organisms; 'no effect'
level in fathead minnow).
- Biodegradation Half-Life Analysis
- Exposure Assessment (estimation of water solubility, bioconcentration factor,
soil adsorption constant, and hydrolysis half-life).
- Phytotoxicity Assessment (functional groups that inhibit photosynthesis).
- Genetic/Mutagenic Assessment (flags possible carcinogens on the basis of
structure).
PRODUCER: EPA Project maintained by Hunter Systems
UPDATED: As Required
The QSAR System is distributed worldwide by TDS Numerica , and is available
online and on diskette.
Sample search for Formaldehyde:
Results of Search by CAS #:
Chemical and Physical Properties Worksheet
CAS: 50-00-0
Name: Formaldehyde
SMILES: O=C
# Property Value and Units Source Method Error
1 Mol Wgt. 30.01 g/mol Calc.
2 Parachor 76.20 Calc.
3 Mol Ref. 6.83 Calc. Av. % Error = 5
4 Mol Vol. 35.00 cm^3/g m Calc.
5 LogP 0.18 Calc. R=0.926, N=893,S=.496
6 Melt Pt. -92.00 C Meas.
7 Boil Pt. -20.00 C @ 760mm Meas.
8 V.Press. 2619.54 mm. Hg Calc. Av. % Error = 2.5
9 Ht. Vpr. 5222.28 cal/mol Calc. Av. % Error = 1.85
10 pKa
11 LOG (S) 0.33 Mol/L Calc. ????
Property C)hanged or D)etailed. Connectivity I)dices or Q)uit:
Ecotox:
Evaluation/Assessment MENU
Options:
1) QSAR Estimates for Exposure Assessment
2) Biodegradation Half-Life Analysis
3) Henry's Law Constant and Environmental Partitioning
4) Aquatic Toxicity Estimates
5) Phytotoxicity Assessment
6) Genetic/Mutagenic Assessment
7) All (1 thru 6)
x) Exit to Main Menu
Input Option:
The menu format, flexible search options, and accurate estimates make QSAR an
extremely useful data
source when limited information is available about a compound.