Agriculture Reference
In-Depth Information
Figure 5.7
Multiple-objective
plot of two candidate chemical
mixtures to be used to remove
fingernail polish from consumers.
Both products appear to have an
affinity for the air. Product 1 has a
larger half-life (i.e., is more
persistent), whereas product 2 is
more carcinogenic, flammable,
and likely to be taken up by the
lungs. Based on these factors, it
appears, at least at the screening
level, that product 1 is
comparatively better from a
sustainability standpoint.
Nail Polish Remover #1
Nail Polish Remover #2
Vapor pressure (mmHg)
Aquatic toxicity, fish (ppm)
Henry's law constant
(dimensionless)
Aquatic toxicity,
green algae
(ppm)
STP air
stripping (%)
Water solubility (ppm)
Bioconcentration factor
(dimensionless)
Atm. oxidation potential,
half-life (hours or days)
STP sludge
sorption (%)
Biodegradation
(dimensionless)
STP total
removal (%)
Biodegradation
(fast/not fast)
Carcinogenic potential1
Hydrolysis @ pH 7 (time)
Flammability, flash pint (°c)
Human inhalation: threshold
limit value (mg m
-3
)
Hydrolysis
: the potential of the chemical to be broken down into a by-
product and water. It has units of time for a pH of 7. A long hydrolysis time
is on the order of many years.
Flammability
: the chemical's flash point (
◦
C).
Human inhalation
: the threshold limit for inhalation of the chemical be-
low which there will be no observed effect in humans. A value of
500 mg m
−
3
and above is a high concentration for which there is little
effect. The chemical becomes more of a problem when the limit is 50 mg
m
−
3
or less.
Carcinogenicity
: the potential for the chemical to cause cancer. These data
are usually somewhat uncertain, due to inaccurate dose-response curves.
STP total removal
: the percent of the chemical that is removed in a wastewater
treatment process. A removal value 90 to 100% is desirable, whereas 0 to
10% removal describes a chemical that is tough to treat.
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