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Publications
Scheduled Wastes Fact Sheet
Number 4 February 1997
The term organochlorine refers to a wide range of organic chemicals, which contain chlorine and sometimes several other elements. A range of organochlorine compounds have been used in Australia, including herbicides, insecticides, fungicides and industrial chemicals such as polychlorinated biphenyls (PCBs). The compounds are characteristically very stable.
This characteristic is widely recognised as being a problem in some uses such as pesticides and transformer oils, because the chemicals can be distributed in the environment where they persist long after their original use. They degrade slowly and being fat-soluble, accumulate in the food chain, eventually ending up in the fat of our bodies.
This fact sheet is not a comprehensive history but rather, a broad outline of the general uses of organochlorine pesticides in Australia since the 1950s when they became popular.
Key properties of organochlorines which cause concerns are persistence and toxicity. While organochlorine pesticides were manufactured for their toxicity, the fact that they were also persistent had advantages in that they remained effective against target pests for prolonged periods. Therefore the chlorinated organic compounds held an important position in pest control in agriculture for a long time, being versatile and, against some pests, very effective.
Since they were first introduced into Australia in the mid-1940s, organochlorine pesticides have been used in many commercial products, in different forms (eg powders and liquids) and in different types and sizes of containers. Originally, organochlorine pesticides were widely and commonly used to protect crops, livestock, buildings and households from the damaging effects of insects.
Commonly used OCP insecticides were DDT, lindane, chlordane, dieldrin, aldrin and heptachlor. Fungicides included hexachlorobenzene (HCB) and chlorinated phenols such as pentachlorophenol. The herbicide 2, 4, 5 -T was also used.
DDT came into use in the 1940s and was widely introduced into Australia and New Zealand agriculture in the 1950s. It was the first highly effective broad-spectrum insecticide which gave an extremely high level of control over many important insect pests. It has low "acute" toxicity to humans, and as such was widely acclaimed as a wonder chemical. It was also used in large quantities in the control of mosquitoes which caused malaria in tropical countries. There has been a total ban on the use of DDT in Australia since 1987.
Chlordane, dieldrin, aldrin and heptachlor, a related group of chlorinated organic compounds, were marketed to complement DDT.
Chlordane was used for instance to control termites, various types of ants, borers, lawn beetles, curl grubs, cut worms and black beetles.
Dieldrin was widely used against locusts and argentine ants; in the protection of electricity and telephone cable; soil treatment in farm and industrial premises for control of termites; and control of termites in buildings, fences and similar structures.
Aldrin was used as a soil treatment, usually pre-planting, for crops such as sugar cane; it was used in ant control as well as subterranean termite control; the protection of power poles from termites; farm, industrial and domestic control of fleas, flies, lice and mites.
Heptachlor was used similarly to chlordane. It was also commonly used in soil treatment in crops for control of funnel ants and grubs of the grey-black beetle in cane growing areas, and banana beetle borer in banana plantations.
To illustrate some difficulties arising from the use of OCPs, the following description indicates how pesticides enter the food chain and have significant impact on production and international trade.
Between 1967 and 1977 both aldrin and dieldrin were used extensively in the production of tobacco crops in Victoria. Aldrin was used to control wire worm/black beetle and dieldrin to control grasshoppers. In 1976-77 there were 3600 hectares devoted to tobacco farming in Victoria, of which 3000 hectares could have been regularly treated with aldrin and/or dieldrin. Cattle grazing land that had been used for tobacco growing retained the OCPs, which reached detectable levels in the animals' flesh. So serious was the impact that between 1987 and 1991 a total of 35 herds grazing on ex-tobacco properties were quarantined because of concerns over the levels of organochlorine residues in export cattle.
The insecticide Lindane is more than 5-20 times more toxic to insects than DDT. It was mainly used against plant eating insects, but had various medical and veterinary applications in treating skin parasites. More specifically, it was used in the control of insect pests in stored seed; to control white grubs and symphylids in pineapples; against ectoparasites on food, and head lice in humans. It was deregistered for general use in 1985.
Hexachlorobenzene (HCB), used in the past as a fungicide (seed disinfectant, seed paint) but now banned in Australia, appears as a widespread contaminant in many environments. It was deregistered for general use between 1985 and 1987.
Chlorinated phenols such as pentachlorophenol (PCP), have been widely used in Australia to protect softwood timber from decay.
2, 4, 5-T was used in the past as a herbicide against broad-leaved woody plants, as a defoliant.
It is important to note that the use of almost all the chemicals mentioned above is now banned in Australia, and that a nationwide plan is being developed for their overall management.
Contact your State or Territory environment protection body in the first instance.
Or you may contact the;
Chemical Policy Section
Department of the Environment and Heritage
E-mail: ocp@environment.gov.au