paradichlorobenzene (PDB) Chemical Profile 1/85
CHEMICAL name: 1,4-dichlorobenzene (56)
TRADE name(S): PDB, Paracide (56)
FORMULATION(S): Available as pure crystals; crystalline material
pressed into various forms; solutions in volatile
solvents or in an oil suspension to apply at base
of trees in peach tree borer control (56).
BASIC PRODUCER(S): PPG Industries
1 Gateway Center
Pittsburgh, PA 15272
STATUS: General use
PRINCIPAL USES: Tobacco as a plant bed treatment for disease
control. It is also used as a fumigant for clothes moths in fabric,
and for ant control. Used on apricots, cherries, nectarines, peaches
and plums for insect control. Also used as a fumigant and repellent in
combination with other materials to control squirrels, moles, gophers,
and rats and to repel cats and dogs (8c).
Widely used in the production of low pressure aerosols because of
its insecticidal action and its properties as a solvent. Used in
tobacco seed beds for blue mold control.. Used industrially to control
mildew and molds on leather and fabrics in closed containers. Used as
a moth repellent in the form of moth balls. Used to repel cats and
dogs both indoor and outdoors (8c).
Important Pests Controlled: Soil diseases, peach tree borer, clothes
moths, root aphid, centipedes, ants, wire worms, potato weevil and a
few other soil insects (8c).
II. PHYSICAL PROPERTIES
MOLECULAR FORMULA: C6 H4 Cl2 (3)
MOLECULAR WEIGHT: 147 (14)
PHYSICAL STATE: Colorless solid (14)
ODOR: Mothball-like odor (14)
MELTING POINT: 53 C (127 F) (14)
BOILING POINT: 174 C (345 F)/760 mm Hg (14)
VAPOR PRESSURE: 0.4 mm Hg at 20 C (68 F) (14); volatile-sublimes
SOLUBILITY: 0.008 g/100 g water at 20 C (68 F) (14).
III. HEALTH HAZARD INFORMATION
OSHA STANDARD: 75 ppm (450 mg/m3) averaged over an eight-hour work
NIOSH RECOMMENDED LIMIT: NA
ACGIH RECOMMENDED LIMIT: TWA (Time Weighted Average) = 75 ppm, 450
mg/m3; STEL (Short Term Exposure Limit) = 110 ppm,
675 mg/m3 (15c).
A. ACUTE TOXICITY
DERMAL: LD50 = 6,000 mg/kg. May be irritating to the skin
ORAL: LD50 = 500 mg/kg (rat) (56).
INHALATION: p-Dichlorobenzene irritates the upper respiratory
EYES: p-Dichlorobenzene vapor irritates the eyes (14).
B. SUBACUTE AND CHRONIC TOXICITY:
A group of animals repeatedly exposed to 798 ppm developed eye
irritation, marked tremors, weakness, and loss of weight; some died.
Reversible, nonspecific changes in the eye grounds were noted in
rabbits, but there were no lens changes; other effects were
centrolobular necrosis of the liver and mild damage to the lungs and
kidneys. In five cases of intoxication from exposure to
p-dichlorobenzene used as a mothproofing agent, one person with only
moderate exposure complained of severe headache, periorbital swelling,
and profuse rhinitis, which subsided 24 hours after cessation of
exposure. The other four persons who had more prolonged exposure
developed anorexia, nausea, vomiting, weight loss, and hepatic necrosis
with jaundice; two died, and another developed cirrhosis. In 8 workers
exposed for an average of 4.8 years (range, 8 months to 25 years) to
p-dichlorobenzene at levels of 10 to 725 ppm, there was no evidence of
hematologic effects; painful irritation of the eyes and nose was
recorded at levels between 50 and 80 ppm, and it was severe at 160 ppm.
A case of allergic purpura induced by p-dichlorobenzene has been
reported. In a study of workers engaged in synthesizing or otherwise
handling p-dichorobenzene, it was concluded that urinary excretion of
2,5-dichlorophenol (a metabolite of p-dichlorobenzene) can serve as an
index of exposure. Published studies of tests for carcinogenicity are
considered to have been too short in duration and involved too few
animals to have any significance (14).
IV. ENVIRONMENTAL CONSIDERATIONS
Toxic to roots, seeds and seedlings as soil disinfectant (69).
Improper use may result in serious injury to trees (8c).
V. EMERGENCY AND FIRST AID PROCEDURES
The chemical information provided below has been condensed from
original source documents, primarily from "Recognition and Management
of Pesticide Poisonings", 3rd ed. by Donald P. Morgan, which have been
footnoted. This information has been provided in this form for your
convenience and general guidance only. In specific cases, further
consultation and reference may be required and is recommended. This
information is not intended as a substitute for a more exhaustive
review of the literature nor for the judgement of a physician or other
If poisoning is suspected, do not wait for symptoms to develop.
Contact a physician, the nearest hospital, or the nearest Poison
KNOWN OR SUSPECTED ADVERSE EFFECTS: Mild respiratory irritant and
Exposure to p-dichlorobenzene may cause irritation of the eyes,
nose, and throat. It may also cause headache, swelling around the eyes,
and runny nose. In addition, it may cause loss of appetite, nausea,
vomiting, weight loss, and liver damage with yellow jaundice and
death. Particles of solid p-dichlorobenzene in contact with eyes may
cause pain. The solid material also produces a burning sensation when
held in contact with the skin with slight irritation. Warm fumes or
strong solutions of p-dichlorobenzene may irritate the skin slightly on
prolonged or repeated contact. Red blotching of the skin due to
allergy to p-dichlorobenzene may occur (14).
SKIN CONTACT: WASH contaminated SKIN with soap and water (25).
INGESTION: INGESTIONS of SMALL amounts (less than 10 mg/kg
body weight) occurring less than an hour before tretment, are probably
best treated by:
A. SYRUP OF IPECAC, followed by 1-2 glasses of water. Dose for
adults and children over 12 years: 30 ml. Dose for children
under 12 years: 15 ml.
B. ACTIVATED CHARCOAL - Administer 30-50 gm as a slurry in tap water,
after vomiting stops.
C. SODIUM OR MAGNESIUM SULFATE, 0.25 gm/kg in tap water, as a cathartic
INHALATION: If a person breathes in large amounts of
p-dichlorobenzene, move the exposed person to fresh air at once. If
breathing has stopped, perform artificial respiration. Keep the
affected person warm and at rest. Get medical attention as soon as
EYE CONTACT: FLUSH contaminated EYES with copious amounts of
fresh water for 15 minutes (25).
NOTES TO PHYSICIAN:
INGESTIONS of LARGE amounts (more than 10 mg/kg) occurring less than an
hour before treatment, should probably be treated by gastric lavage:
A. INTUBATE stomach and ASPIRATE contents.
B. LAVAGE stomach with slurry of ACTIVATED CHARCOAL IN 0.9% saline.
Leave 30-50 gm activated charcoal in the stomach before
C. SODIUM SULFATE, 0.25 gm/kg in tap water, as a cathartic.
CAUTION: Hydrocarbons (kerosene, petroleum distillates) are
included in some formulations of these chemicals.
Ingestion of very LARGE AMOUNTS may cause CNS
depression. In this case, IPECAC IS CONTRAINDICATED.
Also, gastric intubation incurs a risk of HYDROCARBON
PNEUMONITIS. For this reason observe the following
(1) If the victim is unconscious or obtunded and
facilities are at hand, insert an ENDOTRACHEAL TUBE
(cuffed, if available) prior to gastric intubation.
(2) Keep victim's head BELOW LEVEL OF STOMACH during
intubation and lavage (Trendelenburg, or left
lateral decubitus, with head of table tipped
downward). Keep victim's head turned to the left.
(3) ASPIRATE PHARYNX as regularly as possible to remove
gagged or vomited stomach contents.
INGESTIONS occurring MORE THAN an HOUR before treatment are probably
best treated only by ACTIVATED CHARCOAL, 30-50 gm, and SODIUM or
MAGNESIUM SULFATE, 0.25 gm/kg, as described above.
There are no specific antidotes for these chemicals. Because
manifestations of toxicity do occasionally occur in peculiarly
predisposed individuals, MAINTAIN CONTACT with victim for at least 72
hours so that unexpected adverse effects can be treated promptly (25).
VI. FIRE AND EXPLOSION INFORMATION
GENERAL: Flash point: 65.6 C (150 F) (closed up). Hazardous
decomposition products: Toxic gases and vapors (such as hydrogen
chloride and carbon monoxide) may be released in a fire involving
EXTINGUISHER TYPE: Foam, carbon dioxide, dry chemical (14).
No incompatibilities. Liquid p-dichlorobenzene will attack some
forms of plastics, rubber, and coatings (14). Noncorrosive (8c).
VIII. PROTECTIVE MEASURES
STORAGE AND HANDLING: Keep containers tightly closed to avoid
PROTECTIVE CLOTHING: Employees should be provided with and required to
use impervious clothing, gloves, face shields (eight-inch minimum), and
other appropriate protective clothing necessary to prevent repeated or
prolonged skin contact with solid paticles or vapors from the surface
of hot p-dichlorobenzene. Employees should be provided with and
required to use dust- and splash-proof safety goggles where
p-dichlorobenzene or liquids containing p-dichlorobenzene may contact
the eyes (14).
RESPIRATORY PROTECTION FOR p-DICHLOROBENZENE
Minimum Respiratory Protection*
Condition Required Above 75 ppm
1,000 ppm or less A chemical cartridge respirator with a
full facepiece, an organic vapor
cartridge(s), and dust filter.
A gas mask with a chin-style or a front-
or back-mounted organic vapor canister
and dust filter.
Any supplied-air respirator with a full
facepiece, helmet, or hood.
Any self-contained breathing apparatus
with a full facepiece.
Greater than 1,000 ppm or Self-contained breathing apparatus with
entry and escape from a full facepiece operated in
unknown concentrations pressure-demand or other positive
A combination respirator which includes
a Type C supplied-air respirator with a
full facepiece operated in
pressure-demand or other positive
pressure or continuous-flow mode and an
auxiliary self-contained breathing
apparatus operated in pressure-demand or
other positive pressure mode.
Fire Fighting Self-contained breathing apparatus with
a full facepiece operated in
pressure-demand or other positive
Escape Any gas mask providing protection
against organic vapors and particulates.
Any escape self-contained breathing
* Only NIOSH-approved or MSHA-approved equipment should be used (14).
IX. PROCEDURES FOR SPILLS AND LEAKS
IN CASE OF EMERGENCY, CALL, DAY OR NIGHT
PESTICIDE TEAM SAFETY NETWORK/CHEMTREC
Persons not wearing protective equipment and clothing should be
restricted from areas of spills until cleanup has been completed.
If p-dichlorobenzene is spilled, the following steps should be
1. Ventilate area of spill.
2. For small quantities, sweep onto paper or other suitable material,
place in an appropriate container and burn in a safe place (such as
a fume hood). Large quantities may be reclaimed; however, if this
is not practical, dispose in a suitable combustion chamber
equipped with an appropriate effluent gas cleaning device as in
below or desposit in a secured sanitary landfill.
Waste disposal methods:
p-Dichlorobnezene may be disposed of:
1. By making packages of p-dichlorobenzene in paper or other
flammable material and burning in a suitable combustion chamber
equipped with an appropriate effluent gas cleaning device.
2. By dissolving p-dichlorobenzene in a flammable solvent (such as
alcohol) and atomizing in a suitable combustion chamber equipped
with an appropriate effluent gas cleaning device (14).
X. LITERATURE CITED
3. The Condensed Chemical Dictionary, 8th ed. 1971. VanNostrand
Reihnold Co., New York, NY. 971 pp.
8c. Thomson, W.T. 1980. Agricultural chemicals - book III:
fumigants, growth regulators, repellents, and rodenticides.
1981 revised ed. Thomson Publications, Fresno, CA. 182 pp.
14. U. S. Department of Health and Human Services, National Institute
for Occuptational Safety and Health. 1981. Occupational
health guidelines for chemical hazards. F. W. Mackinson, R.
S. Stricoff, L. J. Partridge, Jr., and A. D. Little, Inc.,
eds. DHHS (NIOSH) Publ. No. 81-123. Washington, DC.
15c. American Conference of Governmental Industrial Hygienists. 1984.
TLVs: threshold limit values for chemical substances and
physical agents in the work environment and biological exposure
indices with intended changes for 1984-85. Cincinnati, OH.
25. Morgan, D.P. 1982. Recognition and management of pesticide
poisonings, 3rd ed. U.S. Environmental Protection Agency,
Washington, DC. 120 pp.
56. Farm Chemicals Handbook, 70th ed. 1984. R. T. Meister, G. L.
Berg, C. Sine, S. Meister, and J. Poplyk, eds. Meister
Publishing Co., Willoughby, OH.
69. Harding, W. C. 1981-1982. Pesticide profiles, part three:
fumigants, repellents, and rodenticides. Univ. Maryland,
Coop. Ext. Service Bull. 288, 25 pp.