Section 1 - CHEMICAL PRODUCT AND COMPANY IDENTIFICATION

PRODUCT NAME

P-DINITROBENZENE

NFPA

PRODUCT USE

Organic syntheses; dyes; camphor substitutes. Intermediate

SYNONYMS

C6-H4-N2-O4, "benzene, 1, 4-dinitro", "benzene, 1, 4-dinitro", para-dinitrobenzene,
dinitrobenzene, "Dithane A4"

Section 2 - HAZARDS IDENTIFICATION

CANADIAN WHMIS SYMBOLS

EMERGENCY OVERVIEW

RISK

Heating may cause an explosion.
Heating may cause an explosion.
Danger of cumulative effects.
Limited evidence of a carcinogenic effect.
Very toxic by inhalation, in contact with skin and if swallowed.
Very toxic to aquatic organisms, may cause long- term adverse effects in the
aquatic environment.

POTENTIAL HEALTH EFFECTS

ACUTE HEALTH EFFECTS

SWALLOWED

  Severely toxic effects may result from the accidental ingestion of the material; animal experiments indicate that ingestion of less than 5 gram may be fatal or may produce serious damage to the health of the individual.  The substance and/or its metabolites may bind to hemoglobin inhibiting normal uptake of oxygen. This condition, known as "methemoglobinemia", is a form of oxygen starvation (anoxia).  Symptoms include cyanosis (a bluish discoloration skin and mucous membranes) and breathing difficulties. Symptoms may not be evident until several hours after exposure.  At about 15% concentration of blood methemoglobin there is observable cyanosis of the lips, nose and earlobes. Symptoms may be absent although euphoria, flushed face and headache are commonly experienced. At 25-40%, cyanosis is marked but little disability occurs other than that produced on physical exertion. At 40-60%, symptoms include weakness, dizziness, lightheadedness, increasingly severe headache, ataxia, rapid shallow respiration, drowsiness, nausea, vomiting, confusion, lethargy and stupor. Above 60% symptoms include dyspnea, respiratory depression, tachycardia or bradycardia, and convulsions. Levels exceeding 70% may be fatal.  Dinitrobenzenes (DNB) are highly toxic substances exhibiting various signs and symptoms of involvement of the blood, chiefly methaemoglobinaemia. Fatalities rarely occur from DNB exposures however. In subacute poisonings caused by DNB, symptoms may be precipitated by sunlight or by ingestion of alcohol.  

EYE

  Although the material is not thought to be an irritant, direct contact with the eye may cause transient discomfort characterized by tearing or conjunctival redness (as with windburn). Slight abrasive damage may also result. The material may produce foreign body irritation in certain individuals.  

SKIN

  Skin contact with the material may produce severely toxic effects; systemic effects may result following absorption and these may be fatal.  The material is not thought to be a skin irritant (as classified using animal models). Abrasive damage however, may result from prolonged exposures. Good hygiene practice requires that exposure be kept to a minimum and that suitable gloves be used in an occupational setting.  Contact with dinitrobenzenes (DNB) may produce a yellowish discolouration of the skin and hair. Sufficient material may be absorbed through skin to produce marked cyanosis, followed by hepatitis.  Open cuts, abraded or irritated skin should not be exposed to this material.  Entry into the blood-stream, through, for example, cuts, abrasions or lesions, may produce systemic injury with harmful effects. Examine the skin prior to the use of the material and ensure that any external damage is suitably protected.  

INHALED

  Inhalation of dusts, generated by the material, during the course of normal handling, may produce severely toxic effects; these may be fatal.  The material is not thought to produce respiratory irritation (as classified using animal models). Nevertheless inhalation of dusts, or fume, especially for prolonged periods, may produce respiratory discomfort and occasionally, distress.  Persons with impaired respiratory function, airway diseases and conditions such as emphysema or chronic bronchitis, may incur further disability if excessive concentrations of particulate are inhaled.  Workers exposed by inhalation, to dinitrobenzenes (DNB) complain of an unpleasant taste of bitter almond, burning sensations to the mouth, dry throat, and thirst.  Poisoning may produce liver injury and cause jaundice and hepatomegaly or atrophy. Neurotoxic effects may include ringing of the ears, hearing loss, reduced vision, heightening of reflex, and convulsions. Other symptoms may include diarrhoea, rapid and weak pulse, and decreased blood pressure.  

CHRONIC HEALTH EFFECTS

  Repeated or long-term occupational exposure is likely to produce cumulative health effects involving organs or biochemical systems.  There has been concern that this material can cause cancer or mutations, but there is not enough data to make an assessment.  Long term exposure to high dust concentrations may cause changes in lung function i.e. pneumoconiosis; caused by particles less than 0.5 micron penetrating and remaining in the lung. Prime symptom is breathlessness; lung shadows show on X-ray.  Dinitrobenzenes (DNB) may cause reproductive disorders.  Chronic exposure may produce a particular form of methaemoglobinaemia.  Repeated or prolonged exposure may produce respiratory tract irritation, anaemia, and liver injury. Visual disturbance may be manifested by reduction in acuity and central scotomatas, particularly for red and  green. Retinal haemorrhage has been reported. Anorexia, burning pain and paresthesias in the feet, ankles and forearms, excitation, insomnia, disorientation, memory loss, and convulsions may also occur.