Naphthalene

91-20-3

Moth ball manufacturing; manufacturing of alpha- and beta-
naphthols and pesticides and fungicides; asphalt and naphtha
constituent.

Chemicals; resins; manufacture hydronaphthalene; smokeless
powder; insecticide 2842; veterinary; medical.

White flakes or powder

128.18

Evaporation from water: calculated half-life (25 °C): 7.15 hr
(Verschueren 1983).

Due to the relatively high vapour pressure and low solubility 
of naphthalene, volatilisation from water bodies to the 
atmosphere is likely to be an important process. 
The half-life 
of naphthalene in an air-water system for a water depth of 1 m 
was calculated to be 7.15 hours (EU RA Report 2003).

The fate of naphthalene in two sandy loam soil (organic content 
0.5% and 1.1%) was evaluated in the laboratory. 
The soils were 
incubated with naphthalene at 25 °C for 48 hr hours and 
approximately 30% of naphthalene was volatilised in this time 
(EU RA Report 2003).

The sorption of naphthalene on pond and river sediments was 
investigated by equilibration of variable amounts of 
napthtalene with constant concentration of two types of 
sediment with organic carbon contents of approximately 3%. 
The 
adsorption fitted well well to linear isoterms over a range of 
water phase concentrations. 
The sediment organic carbon-water 
partition coefficient was calculated to 1,300 (EU RA Report 
2003).

The adsorption of naphthalene was easured in five soils 
(organic carbon content 1.09 - 5.92%) at one initial 
concentration assuming a linear adsorption isotem. 
The soil 
organic matter-water partition coefficient (Kom) was calculated 
to be 240 (EU RA Report 2003).

Measurements of adsorption behaviour of naphthalene were 
performed on the basis of OECD test guidelines for "Adsorption/
Desorption. 
Equilibria were determined for five different 
concentrations so the adsorption isoterm and adsorption 
coefficient could be detemined. 
The soil carbon-water partition 
coefficient for four soils were in good agreement (3,200, 
1,600, 1,300 and 1,400) (EU RA Report 2003).

The sorption of naphthalene for ten Danish soils was determined
in laboratory studies by battch equilibrium experiments. 
The 
adsorption significantly correlated with the organic carbon 
content of the soils tested. 
The correlations with other 
factors tested such as pH, cation-exchange capacity and 
particle-size distribution were not significant. 
The sorption 
of naphthalene was found to be partially reversible in four out 
of ten soils tested. 
A range of soil organic carbon-water 
partition coefficients (Koc) were measured from 520-2100 (mean 
= 1100). 
These values were influenced by the uncertainty of 
determination of organic carbon, which is relatively large at 
low levels (EU RA Report 2003).

Sorption of naphthalene on a contaminated soil was investigated 
by batch experiments using initial naphthalene concentrations 
of approximately 0.5 - 10 mg/l. 
The soil organic carbon-water 
partition coefficient was 989 (organic carbon content 0.18%) 
(EU RA Report 2003).

Flammability moderate. 
Gives off flammable vapors when heated.

Autoignition point: 567 °C.

Vapor forms explosive mixtures with air. 
Highly reactive.

Atmospheric photolysis half-life:
550d - 71d, calculated from quantum yield for photolysis in
water irradiated at 313 nm and for sunlight photolysis at
latitude 40°N at midday in the summer in near-surface water and
in a 5 meter deep inland water body.

Photooxidation half-life in air:
29.6hr - 2.96hr, based upon measured rate constants for
reaction with hydroxyl radical in air (Howard 1991).

A value of 2.4x10-11 cm3xmolecule-1x sec-1 for the specific 
degradation rate constant with OH radicals, combined with the 
standard OH concentration of 5x10+5 molecules/cm3 gives a 
half-life of 16 hours.

Aquatic photolysis half-life:
550d - 71d, calculated from quantum yield for photolysis in
water irradiated at 313 nm and for sunlight photolysis at
latitude 40°N at midday in the summer in near-surface water and
in a 5 meter deep inland water body (Howard 1991).

Naphthalene was added to distilled or artificial seawater in a  
reaction flask and irradiated. 
A high-pressure mercury lamp was
used irradiate flask for 1-96 hr. 
The half-life of naphthalene  
in distilled water was 25 hours and in artificial seawater the
rate of photolysis was found to increase several times over.

The direct photolysis of naphthalene was studied in pure water. 

A calculated near surface half-life was 71 hours, corresponding
to midsummer sunlight at midday, latitude 40°N. 
A calculated 
half-life of 550 hours was got for a 5-metre deep-water body 
with 20 mg/l sediment - the effect of partitioning to the 
sediment on the half-life was considered negligible (EU RA 
Report 2003).

Aerobic half-life:
20d - 12hr, based upon die-away test data for an oil-polluted 
creek and for an estuarine river (Howard 1991).

Anaerobic half-life:
258d - 25d, based upon anaerobic astuarine sediment die-away 
tes data at pH 8 and pH 5 (Howard 1991).

Biodegradation:
2% by BOD
period: 28d
substance: 30 mg/l
sludge: 100 mg/l
(MITI 1992)

Biodegrades at slow-moderate rate. 
Half-life in < saturated
solution (top meter) is estimated to be 2.9 hours; as a result
of evaporative losses. 19 % evaporates with first 0.01 % of
water (Sax 1986).

Subject to biodegradation: First degradation product is
§salicylic acid, next to catechol and b-ketoadipic acid. 
A
second degradation route results in 1,2-naphthoquinone
(Sax 1986).

Degradation of naphthalene:
*--------------------------------------------------------------*
ENVIRONMENT  INIT.CONC   REDOX-        TEMP   DEGRADATION  REF.
             mg/l        COND.         °C       %/day
*--------------------------------------------------------------*
water        2.48        aerobic       -       99/17       a
water        1 - 3       aerobic       20     100/8        b
water        1 - 3       anaerobic     20       0/41       b
water          5         aerobic       25     100/7        c
water         10         aerobic       25     100/7        c
groundwater   10         aerobic       10      28/7        d
groundwater   10         aerobic       10     100/9        d
groundwater  0.45 - 1.33 aerobic    10 - 13   100/4        e
groundwater  0.45        aerobic    10 - 13    95/4        e
groundwater  0.014       aerobic       -      >99/1        f
sediment       -         anaerobic     30       0/36       g
sediment       -         anaerobic  20 - 30     0/233      h
soil         0.000042    aerobic       20       0/14       i
*--------------------------------------------------------------*
a) Battermann 1984            f) Bouwer 1987
b) Delfino & Miles 1985       g) Delaune et al. 1980
c) Tabak et al. 1981          h) Ward & Brock 1976
d) Kappeler & Whurmann 1978   i) Hutchins & Ward 1984
e) Jensen et al. 1985         (Anon. 1987b).

Summary of aerobic degradation rates of naphthalene
---------------------------------------------------------------
Degradation      Description
---------------------------------------------------------------
2% (BOD) 4 w     301 C Modified MITI test (I) or 302 C Mofidied
                 MITI test (II)
99% in 2.8-8 hr  Batch reactor with acclimated sludge, mineral
                 salts and naphthalene aerobic conditions
99% in 6 days    Aerobic degradation in intertidal marine
                 sediments
100% in 2 d      Naphthalene added to groundwater
(6 d lag)
90% after 10 d   Silty loam soils incubated with naphthalene
100% within 60d  (20 mg/kg) at 30°C
100% in 10d,     Mineral medium mixed with soil and stock
2d acclimation   solution of naphthalene (aerobic conditions)
50% in 11-18 d   Microcosms constructed using contaminated
                 aquifer soil and groundwater samples with 14C-
                 labelled naphthalene incubated at 10 °C
79.1% in 14 d    Bacteria cultured in mineral medium
                 supplemented with naphthalene
---------------------------------------------------------------
(EU RA Report 2003)

The results of only standardised screening test for inherent 
biodegradability for naphthalene suggest that napthtalene is 
not inherently biodegradable (2% degradation after 4 weeks). 

However, numerous other "not-standard" biodegradation tests 
suggest that it is easyly degradaed under aerobic and 
denitrifying conditions, particularly where acclimated 
microorganisms are used, with napthtalene falling below 
measurable levels within 8-12 days in a number of tests. 

Naphthalene has therefore been considered to be inherently 
biodegradable in the risk assessment. 
Based on this the EUSES 
model indicates the fate of naphthalene in a wastewater 
treatment plants as: 27.4% to air; 34.8% to water; 11.2% to 
sludge; and 26.6% degraded (EU RA Report 2003).

Although there are no standard tests for anaerobic degradation, 
the results suggest that naphthalene is resistant to 
biodegradation under anaerobic conditions. 
Some tests show no 
significant reduction in naphthalene levels for the duration of 
the test. 
Other showed 90-100% reduction within about 50-60 
days (EU RA Report 2003).

Confirmed to be non-accumulative or low accumulative
(Anon. 1987).

Bioconcentration factor (crustaceans):
4000 - 6000 (Verschueren 1983).

The bioconcentration factor of naphthalene in a freshwater alga 
(chlorella fusca) was measured using 14C-labelled naphthalene. 

The alga was exposed to naphthalene in a nutrient solution for 
24 hours at room temperature under illumination and agitation. 

The bioaccumulation factor an a wet weight basis measured as 
130 (EU RA Report 2003).

The bioaccumulation of naphthalene in Daphnia magna was 
measured under static conditions and the bioconcentration 
factor was approximately 500. Depuration studies showed that 
naphthalene was released very quickly (EU RA Report 2003).

A flow through system was used study the accumulation of 
naphthalene in carp (Cyprinus carpio). The method used 
corresponds to 305C, Bioaccumulation: degree of bioconcentration 
in fish stipulated in the OECD guide lines for testing 
chemicals. The fish were acclimated at 25+-2 °C prior to 
exposure to a concentration of 0.15 mg/l for 8 weeks. 

Bioconcenration factors of between 36.5 and 168 were measured 
(EU RA Report 2003).

Bioconcentration factors
--------------------------------------------------
Organism         Bioconcentraion factors
--------------------------------------------------
fish             up to 427 (whole body)
                 up to 1158 (individual tissues)
algae            130
Daphnia          50 - 131
marine worm      160 - 300
mussels          27 - 38
clams            2.3
--------------------------------------------------
A value of 279 is derived for the bioconcentration factor using 
the QSAR for substances with log Kow<6 (EU RA Report 2003).

Direct contact: Skin; eyes; respiratory tract
irritant, occasional (Sax 1986).

General sensation: Mothball odour. 
Metabolites of naphthalene
are responsible for the growth of cataracts. -  
Can be absorbed
through skin. 
Symptoms include nausea, vomiting, headache,
diaphoresis, hematuria, hemolytic anemia, fever, hepatic
necrosis, conculsions, and coma (Sax 1986).

5 - 15 g will kill a person. 
Moderately toxic by ingestion or
inhalation (Sax 1986).

Chronic hazard level: Possible dermatitis. 
Slight chronic
hazard with ingestion or inhalation. 
Solid may stay on bottom
and provide equilibrium values for prolonged period (Sax 1986).

Skin and eye irritation data:
skn, rbt, 495, open, mild; eye, rbt, 100 mg, mild (Sax 1986).

Rat - tumor was negative, in oil (in synthetic diet), six times
a week, 10 - 20 mg until dose of 10 g/rat in food (Sax 1986).

Mutagen data:
dnd, mus, ipr, 200 mg/kg (Sax 1986).

Can be toxic to sewage organisms at 2500 ppm (Sax 1986).

Tilapia mossambica, 3.95 mg/l, 4 d, change in enzyme activity
(Dange 1986).

Macrobrachium kistnensis, 0.5957 mg/l, 10 days, biochemical
effect (Sarojini et al. 1987).

LC50 13 mg/l, chr, Chironomus attenuatus
LOEC 0.5 mg/l, phy, chr, Chironomus attenuatus
LC50 13 mg/l, chr, Tanytarsus dissimilas
LOEC 0.5 mg/l, phy, chr, Tanytarsus dissimilas
(Darville & Wilhm 1984).

1.8 mg/l, 72hr, fingerling salmon, critical;
4 mg/l, 1 hr, Lepomis, death;
20 mg/l, Perca fluviatilis, killed;
11 mg/l, 15 mg/l, minnows, killed
(Sax 1986).

LC50, 5.02 mg/l, 48 hr, Physa gyrina
LC50, 3.93 mg/l, 48 hr, Gammarus minus
LC50, 2.81 mg/l, 48 hr, Chironomus tentans
LC50, 3.80 mg/l, 24 hr, Eurytemora affinis
LC50, 1.39 mg/l, 96 hr, Eualis suckleyi
LC50, 2.6 mg/l, 96 hr, Palaemonetes pugio
LC50, 2.35 mg/l, 96 hr, Palaemonetes pugio
(EU RA Report 2003).

Air pollution: high (Sax 1986).

Will produce tastes and BOD in water (Sax 1986).