Naphthalene Cas No. 91-20-3

Naphthalene

Cas No. 91-20-3

Potential sources and exposures

Naphthalene is PAH. The reader should refer to the general profile on PAHs

for exposure information. Naphthalene is found in moth balls; exposure may

arise through inhalation and dermal and ingestion routes.

Physical and chemical properties

Property

Value

Molecular weight

128.2 g/mol

31.7 mg/L at 25 oC

Water solubility

8.2 10-2 mm Hg at 25 oC

Vapor pressure

Koc

940 mL/g

log Kow

3.3

4.8 10-4 atm-m3/mole

Henry's Law Constant

Toxicity

In humans, exposure to sufficient concentrations of naphthalene through

inhalation, ingestion, or dermal contact may cause intravascular hemolysis or the

less severe symptoms of eye irritation, headache, confusion, tremors, nausea,

vomiting, abdominal pain, and bladder irritation. In severe cases hematological

effects have included red cell fragmentation, icterus, severe anemia, leukocytosis

and dramatic decreases in hemoglobin, hemacrit, and red cell counts. Hemolysis

can also lead to renal disease from precipitated hemoglobin (USEPA 1982).

Poisonings have occurred in humans as a result of the ingestion of moth balls as

well as from clothing infants in materials that had been stored in moth balls. A

study of workers exposed to naphthalene for a period of 5 years found corneal

ulceration, cataracts, and some lenticular and general opacities in 8 of the

21 employees examined. No data were located indicating naphthalene to be an

hepatic enzyme inducer.

Ecological effects

A variety of aquatic species has been exposed to naphthalene and most acute

tests were under static procedures with unmeasured test concentrations. All but

two LC50 effect levels for fish and invertebrate species are in the range of 2,300

to 8,900 ug/L. One embryo-larval test with the fathead minnow demonstrated

adverse effects at a test concentration of 850 ug/L.

D50

Appendix D Toxicological Profiles