Chemical |
Benzene, C10-13 alkyl derivs. |
CAS-number : |
67774-74-7 |
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Synonyms : |
LAB |
Linear alkylbenzene |
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Sumformula of the chemical : |
C6H5CnH2n+1; n=10-13
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EINECS-number : |
2670510 |
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Purity, % : |
86 |
86 - 99%, Purity is defined as the degree of the product linearity, namely the percent content of alkylates with C10-13 linear side alkyl chains (EU RA Report 2000). |
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Known impurities : |
Tetralins: 0.5 - 8%; isoalkylbenzenes 1 - 6% (EU RA Report 2000). |
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Uses : |
LAB is almost entirely (> 99%) utilised as intermediate in the
production of linear alkylbenzene sulphonate (LAS).
Some LAB
also finds minor use as solvent and binder in speciality
applications, e.g. cable oil, ink industry, paint and
varnishes, insulating and electricity (EU RA Report 2000).
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State and appearance : |
Liquid.
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Molecular weight : |
239
243 |
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Water solubility, mg/l : |
0.041 |
EU RA Report 2000 |
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Melting point, °C : |
-70 |
<-70 °C, EU RA Report 2000 |
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Boiling point, °C : |
278 |
278 - 314 °C at 1013 hPa, |
314 |
EU RA Report 2000 |
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Log octanol/water coefficient, log Pow : |
7.5 |
7.5 - 9.12, at 25 °C |
9.12 |
EU RA Report 2000 |
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Volatilization : |
Measurement of Henry's Law constant shows a value of 95
Paxm3/mol which means a moderate volatilization from the water
medium (EU RA Report 2000).
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Adsorption/desorption : |
Organic carbon/water partition coefficient (Koc) has been
measured to be 2.2X10+4.
This value was calculated by the
solid/water partition coefficient measured in four types of
soil with different organic carbon content (from 0.4 to 2%) by
addition of 14C-labelled C12 alkylbenzene.
The alkyl length
(C12) of radiolabelled standard represents the average alkyl
chain length (C11.6) of the commercial LAB (EU RA Report 2000).
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Photochemical degradation in air : |
Photochemical transformation studies of acetonitrile solutions
of LAB in direct sunlight indicate no significant direct
photolysis or chemical transformation (EU RA Report 2000).
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Total degradation in soil : |
In sludge amended soils the LAB measured half-life is 15.3 days
with a primary degradation of 98% after 103 days, measured by a
final GC-MS detection analysis (EU RA Report 2000).
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Total degradation in water : |
LAB biodegrades readily.
A biodegradation test, recently
conducted using a manometric respirometric method, shows a
biodegradation of 64.1% after 28 days incubation (EU RA Report
2000).
An OECD 301 B test indicates a biodegradation of 67% (measured
by CO2 evolution), after 28 days.
An adapted inoculum was used.
An emulsifier to disperse the poorly soluble LAB was added (EU
RA Report 2000).
Anaerobic biodegradation: A test conducted following the ECETOC
Technical Report n° 28 shows a biodegatation of > 70% (EU RA
Report 2000).
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Other information of bioaccumulation : |
The log Pow (7.5 - 9.12) would predict a high potential
bioaccumulation in fish but the measured BCF of 35 in a test on
Lepomis macrochirus means a low bioconcentration.
The reason
why the measured BCF is lower than the perdicted one can be
explaned by the high metabolisation rate of substance by the
fish (EU RA Report 2000).
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Other information of water organisms : |
Mysidoposis bahia (after 96 h), Gammarus fasciatus (96 h),
Paratanytarsus (48 h) are not affected at nominal concentration
(1000 mg/l) up to and exceeding the water solubility with a
solvent carrier (EPA, GLP) (EU RA Report 2000).
Tests, conducted on Salmo gairdneri (96 h), Pimephales
promelas, Lepomis macrochirus (96 h) and Leuciscus idus
melanotus (48 h) show no adverse effects at nominal
concentration (1000 mg/l) up to and exceeding the water
solubility with a solvent carrier or using an emulsifier ((EU
RA Report 2000).
Selenastrum capricornutum is not affected after 96 h at nominal
concentration (1000 mg/l) up to and exceeding the water
solubility with a solvent carrier (EPA, GLP) (EU RA Report
2000).
Tests conducted on Daphnia magna at nominal concertration in
static systems for three LABs with average molecular weights of
236, 244 and 262 show LC50 (48 h) = 0.009-0.08 mg/l (EU RA
Report 2000).
One-generation chronic tests (21 d) on Daphnia magna in clean
water and measured concentrations were conducted in
flow-through conditions using acetone as a solvent for two LABs
with molecular weights of 236 and 262.
Survival and reproducton
are recorded and assessed three times; growth established at
day 21.
Concentration was monitored via a GC procedure.
The
lowest no effect level measured for LAB is 0.0075 mg/l (EU RA
Report 2000).
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References |
3345 | EU RA Report 2000.
Existing Substances: benzene, C10-13 alkyl
derivs.
European Union Risk Assessment Report (Vol. 3)
Institute for Health and Consumer Protection.
European
Chemicals Bureau.
European Communites.
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