Handbook of Solvents - George Wypych - ChemTech - Ventech!

2.3 Basic physical and chemical properties 63
Odor. Odor threshold (discussed above) is not a precise tool for estimation concentration
of vapors. The description of odor has little relevance to the identification of solvent but
description of odors in the database may be helpful in the selection of solvent to minimize
odor or make it less intrusive.
UV absorption maxima for different solvents given in the database are useful to predict
the potential effect of solvent on UV absorption from sun light. The collection of data is
also useful for analytical purposes.
Solvent partition - activated carbon and between octanol and water. Solvents can
be economically removed from dilute solutions by activated carbon or ion exchange resins.
Activated carbon partition coefficient which helps to determine the amount of activated carbon
needed to remove a contaminant can be obtained using the following equation:
m w
= [2.3.16]
Pc
where:
w total weight of solvent in solution
P partition coefficient
c residual concentration of solvent remaining after treatment.
The octanol/water partition coefficient is the log of solubility of the solvent in water
relative to that in octanol. This coefficient is used to estimate biological effects of solvents.
It can also be used to estimate the potential usefulness of a solvent extraction from water by
any third solvent.
Soil adsorption constant is a log of the amount of a solvent absorbed per unit weight
of organic carbon in soil or sediment.
Atmospheric half-life of solvents due to reaction in the atmosphere with hydroxyl
radicals and ozone is a measure of the persistence of particular solvent and its effect on atmospheric
pollution.
Hydroxyl rate constant is the reaction rate constant of the solvent with hydroxyl radicals
in the atmosphere.
Global warming potential of a well-mixed gas is defined as the time-integrated commitment
to radiative forcing from the instantaneous release of 1 kg of trace gas expressed
relative to that from the release of 1 kg of CO2. Biodegradation half-life determines persistence of the solvent in soil. Commercial
proprietary solvents mixtures are classified as biodegradable and solvents having known
chemical compositions are classified according to the time required for biodegradation to
cut their initial mass to half.
Target organs most likely affected organs by exposure to solvents. The database
contains a list of organs targeted by individual solvents.
Hazchem Code was developed in the UK for use by emergency services to determine
appropriate actions when dealing with transportation emergencies. It is also a useful to apply
as a label on storage tanks. It consists a number and one or two letters. The number
informs about the firefighting medium to be used. The first letter gives information on explosion
risk, personal protection and action. A second letter (E) may be added if evacuation
is required.