Cumene, CASR number: 98-82-8 and molecular formula: C9H12, is the common name for isopropylbenzene, an organic compound that is based on an aromatic hydrocarbon with an aliphatic substitution. It is a constituent of crude oil and refined fuels.  Cumene is a flammable colourless liquid with a sharp, penetrating, aromatic odour and has a boiling point of 152°C 
Cumene is used to manufacture other chemicals such as phenol, acetone, acetophenone, and methyl styrene. It is used as a thinner in paints, lacquers, and enamels. It is a component of high-octane motor fuels. Cumene is also used in the manufacture of rubber, iron and steel, and pulp and paper.
Sources of Emission & Routes of Exposure [3,4]
Sources of Emission
- Industry sources: The primary sources of cumene are the industries that manufacture it or use it in production. Some of the industries that manufacture it or use it in production are oil refiners, chemical industry, rubber manufacturers, pharmaceutical industry, pulp and paper manufacturing, roofing and paving, plastics manufacturing, manufacturers of paints, varnishes and lacquers. These emissions mainly are to the air, but are also to the soil and water.
- Other possible emitters of cumene are vapours and spilling of petrol, commercial and household painting and paint, varnish and lacquer removal, tobacco smoke, and consumer products containing cumene. These emissions are to the air unless there is a spill.
- Natural sources of cumene include crude petroleum and coal tar. It is also found in the oils of plants, marsh grasses and in some foods.
- Transport sources: Some cumene is found in the exhaust of motor vehicles, jet engines, and outboard motors.
- Consumer products: Some of the consumer products containing cumene are foam plastic insulation, rubber floor and wall coverings, bathmats, vinyl floor tile, wood office desks and furniture (modular) and thinners for paints, lacquers and enamels.
Routes of Exposure
The main routes of exposure to cumene are via the inhalation of contaminated air, or breathing in tobacco smoke. Human exposure occurs mainly by breathing air-containing cumene, from the evaporation of petroleum products. Cumene can also enter the body through the skin. A minor route of exposure is through the ingestion of contaminated food and water.
Acute inhalation exposure to cumene may cause headaches, dizziness, drowsiness, slight incoordination, and unconsciousness in humans. It has a potent CNS depressant action characterised by a slow induction period and long duration of narcotic effects in animals. Acute inhalation exposure also causes CNS depression in rodents. Cumene is a skin and eye irritant in humans and animals. Tests involving acute exposure of rats, mice, and rabbits, have demonstrated cumene to have moderate acute toxicity by inhalation or dermal exposure and low to moderate acute toxicity by ingestion.
Chronic Effects (Noncancer)
No information is available on chronic exposure to cumene in humans. Inhalation studies in rats have reported increased liver, kidney, and adrenal weights. Increased kidney weight was observed in rats chronically exposed to cumene via gavage (experimentally placing the chemical in the stomach). The Reference Concentration (RfC) for cumene is 0.4 milligrams per cubic metre (mg/m3). The Reference Dose (RfD) for cumene is 0.1 milligrams per kilogram body weight per day (mg/kg/d) based on increased kidney weight in rats.
No information is available on the carcinogenic effects of cumene in humans or animals. EPA has classified cumene as a Group D, not classifiable as to human carcinogenicity.
First Aid Measures
- Eye Contact: Check for and remove any contact lenses. Immediately flush eyes with running water for at least 15 minutes, keeping eyelids open. Cold water may be used. Do not use an eye ointment. Seek medical attention.
- Skin Contact: After contact with skin, wash immediately with plenty of water. Gently and thoroughly wash the contaminated skin with running water and non-abrasive soap. Be particularly careful to clean folds, crevices, creases and groin. Cover the irritated skin with an emollient. If irritation persists, seek medical attention. Wash contaminated clothing before reusing.
- Serious Skin Contact: Wash with a disinfectant soap and cover the contaminated skin with an anti-bacterial cream. Seek immediate medical attention.
- Inhalation: Allow the victim to rest in a well-ventilated area. Seek immediate medical attention.
- Serious Inhalation: Evacuate the victim to a safe area as soon as possible. Loosen tight clothing such as a collar, tie, belt or waistband. If breathing is difficult, administer oxygen. If the victim is not breathing, perform mouth-to-mouth resuscitation. Seek medical attention.
- Ingestion: Do not induce vomiting. Examine the lips and mouth to ascertain whether the tissues are damaged, a possible indication that the toxic material was ingested; the absence of such signs, however, is not conclusive. Loosen tight clothing such as a collar, tie, belt or waistband. If the victim is not breathing, perform mouth-to-mouth resuscitation. Seek immediate medical attention.
Exposure Controls and Personal Protection
Provide exhaust ventilation or other engineering controls to keep the airborne concentrations of vapours below their respective threshold limit value. Ensure that eyewash stations and safety showers are proximal to the workstation location.
Personal Protective Equipment
The following personal protective equipment is recommended when handling cumene:
- Splash goggles;
- Lab coat;
- Vapour respirator (be sure to use an approved/certified respirator or equivalent);
Personal Protection in Case of a Large Spill:
- Splash goggles;
- Full suit;
- Vapour respirator;
- A self-contained breathing apparatus should be used to avoid inhalation of the product.
- Note: Suggested protective clothing might not be sufficient; consult a specialist BEFORE handling this product.
NIOSH: TWA 50 ppm (245 mg/m3) [skin]
- OSHA: TWA 50 ppm (245 mg/m3) [skin]
Safe Work Australia has set an 8 hour time weighted average (TWA) of 25ppm and a short term exposure limit (STEL) of 75ppm