Dibutyl phthalate is a man-made chemical that is added to plastics and other chemicals. In plastics it helps keep them soft (a plasticizer). It is also used in elastomers, lacquers, explosives, printing inks, resin solvents, perfume oil solvents, paper coatings, adhesives, and nail polish. It is used as a solid rocket propellant.
Substance name: Dibutyl phthalate
CASR number: 84-74-2
Molecular formula: C16H22O4
Synonyms: DBP; Di-n-Butyl Phthalate; n-Butyl phthalate; 1,2-Benzenedicarboxylic acid dibutyl ester; Phthalic acid dibutyl ester; o-benzenedicarboxylic acid, dibutyl ester; benzene-o-dicarboxylic acid di-n-butyl ester; dibutyl 1,2-benzenedicarboxylate; Benzenedicarboxylic acid, dibutylester; Dibutyl o-Phthalate
Dibutyl phthalate is a colourless, oily liquid with a weak odour.
Melting Point: -35°C
Boiling Point: 340°C
Specific Gravity: 1.043
Vapour Density: 9.6
Dibutyl phthalate is soluble in most organic solvents, but only slightly soluble in water.
The National Pollutant Inventory (NPI) holds data for all sources of dibutyl phthalate emissions in Australia.
Inhalation exposure, at high levels, of dibutyl phthalate may include irritation of the eyes, nose and throat. It may cause nausea, tearing of the eyes, vomiting, dizziness, and headache. Long-term exposures may cause liver and kidney damage. Dibutyl phthalate may harm the developing foetus and the male testes.
Entering the body
Dibutyl phthalate can enter the body when a person breathes air containing it, or when a person drinks water or eats food that has been containing with the compound. Dibutyl phthalate can enter the body through the skin, but this is very slow.
Dibutyl phthalate is used extensively throughout society, it is now widespread in the environment. Most people are exposed to low levels in air, water, and food. In many cases the largest source of exposure is from food containing dibutyl phthalate. Some of the dibutyl phthalate in food is from plastics used to wrap and store the food and certain types of food (especially fish and shellfish) may absorb larger quantities of dibutyl phthalate (from 50 to 500 parts per billion). Air and water also contains small levels of dibutyl phthalate. Levels in city air are found to be 0.03 to 0.06 parts per billion. In drinking supplies it is found at 0.1 to 0.2 parts per billion. At these low levels dibutyl phthalate is not expected to cause any harmful effects.
Exposure at higher levels may occur in a number of ways; workers in the industries that use or produce dibutyl phthalate are at risk of exposure. Consumers can be exposed to higher levels of dibutyl phthalate by exposure to air from production and processing facilities using dibutyl phthalate.
Workplace exposure standards
Safe Work Australia sets the workplace exposure standard for dibutyl phthalate through the workplace exposure standards for airborne contaminants:
- Maximum eight hour time weighted average (TWA): 5 mg/m3
These standards are only appropriate for use in workplaces and are not limited to any specific industry or operation. Make sure you understand how to interpret the standards before you use them.
Drinking water guidelines
There is no guideline for dibutyl phthalate in the Australian Drinking Water Guidelines.
Dibutyl phthalate will exist as both a gas and a particle if released to the atmosphere. It also will be found in the soil and water. Dibutyl phthalate is highly toxic to aquatic life. The toxicity of dibutyl phthalate on plants, birds, and land animals has not been determined. Dibutyl phthalate will bioaccumulate in the tissues of fish and shellfish.
Entering the environment
Industrial emissions of dibutyl phthalate can produce elevated concentrations in the atmosphere around the source. Since it breaks down quickly in the air high levels are not likely to spread far from where it is used. It may also be transported through the environment in the water and the tissues of fish and shellfish.
Where it ends up
Dibutyl phthalate enters the environment during production and use. In the air it will break down into other chemicals in approximately one and a half days. In the water it will be broken down into other chemicals in between 2 and 20 days.
Australian Water Quality Guidelines for Fresh and Marine Waters: (ANZECC, 1992):
Maximum of 4 micrograms/L (i.e. 0.000004 g/L)
The primary sources of dibutyl phthalate emissions are the industries that manufacture it or use it in production. Some of the industries that use it in production are the chemical industry, the plastics industry (a softening agent), machinery manufacturers, and manufacturers of plywood and millwork. These emissions are primarily to the air, with a small percentage to the water, and land.
Diffuse sources, and industry sources included in diffuse emissions data
Commercial and household use and disposal of paints and varnish may release dibutyl phthalate. Manufacturers of plastic parts and carpet backing may release dibutyl phthalate.
Dibutyl phthalate may occur in soils by microbial biosynthesis (manufacture by small organisms).
Consumer products containing dibutyl phthalate may include colognes and perfumes, cosmetics, paints undercoats and primers, plastic products, floor polish, window cleaning products, caulks and sealants, latex type adhesives, resin and rubber adhesives, safety glass, vinyl floors, hairspray and nail polish.
Sources used in preparing this information
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- Australian and New Zealand Environment and Conservation Council (ANZECC) (1992), Australian Water Quality Guidelines for Fresh and Marine Waters.
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- Safe Work Australia, Workplace exposure standards for airborne contaminants, accessed June 2021.
- National Health and Medical Research Council (NHMRC), Australian Drinking Water Guidelines (2011) - Updated October 2017, accessed May 2018