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DESIGNATIONS
CAS No.: 1912-24-9
Registry name: Atrazine
Chemical name: 2-Chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine
Synonyms, Trade names: 6-Chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazin-2,4-diamine, 2-chloro-4-ethylamino-6-isopropylamino-s-triazin, Gesaprim
Chemical name (German): Atrazin, 2-Chlor-4-ethylamino-6-isopropylamino-1,3,5-triazin
Chemical name (French): Atrazine
Appearance: colourless, crystalline solid
BASIC CHEMICAL AND PHYSICAL DATA
Empirical formula: |
C8H14ClN5 |
Rel. molecular mass: |
215.69 g |
Density: |
1.2 g/cm3 |
Boiling point: |
not distillable |
Melting point: |
173-175°C |
Vapour pressure: |
4 x 10-5 Pa |
Solvolysis/solubility: |
in water: approx. 70 mg/l; in ether: 12 g/l (20°C); in methanol: 18 g/l (at 27°C); in n-pentane: 36 mg/l (27°C); in chloroform: 52 g/l (27°C) |
ORIGIN AND USE
Usage:
Atrazine is used as a selective herbicide e.g. for weed control in corn and asparagus, in
the culture of sugarcane and pineapple and in winegrowing (also in combination with e.g.
mecoprop). Additionally, it is used as a total herbicide on roads and public places as
well as on uncultivated ground in combination with amitrol, bromacil, dalapon and growth
promoters. Atrazine inhibits photosynthesis and other metabolic processes in plants.
Origin/derivation:
There are no natural sources of atrazine. It is produced from cyanuric acid chloride with
ethylamine and isopropylamine. The reaction takes place successively in
tetrachloromethane. All the atrazine produced is released into the environment.
Production figures:
World |
90,000 t |
(1976) |
USA |
40,000 t |
(1976) |
EU |
750 t |
(1978/79) |
D |
< 1,000 t |
(1985) |
1,164 t |
(1987) |
Toxicity
Mammals: |
||
Rat |
LD50 3080 mg/kg, oral |
acc. PERKOW, 1985 |
LD50 >5600 mg/kg, dermal |
acc. RIPPEN, 1992 |
|
LC50 > 710 mg/m3 (1h), inhalation |
acc. PERKOW, 1985 |
|
Mouse |
LD50 1750 mg/kg, oral |
acc. PERKOW, 1985 |
Rabbit |
LD50 750 mg/kg, oral |
acc. PERKOW, 1985 |
LD50 7500 mg/kg, dermal |
acc. PERKOW, 1985 |
|
Hamster |
LD50 1000 mg/kg, oral |
acc. RIPPEN, 1992 |
Aquatic organisms: |
||
Rainbow trout |
LC50 8.8 mg/l (96h) |
acc. PERKOW, 1985 |
Perch |
LC50 16 mg/l (96h) |
acc. PERKOW, 1985 |
Carp |
LC50 76 mg/l (96h) |
acc. PERKOW, 1985 |
Green algae |
EC50 0.055 mg/l (inhibition of growth) |
acc. RIPPEN, 1992 |
EC0 0.030 mg/l (inhibition of cell division) |
acc. RIPPEN, 1992 |
|
Plants: |
||
Corn |
>70% effect at 4.5 kg/ha |
acc. RIPPEN, 1992 |
Lettuce |
>70% effect at 0.5 kg/ha |
acc. RIPPEN, 1992 |
Millet |
35-70% effect at 1.6 mg/l |
acc. RIPPEN, 1992 |
Soybean |
35-70% effect at 1.1 mg/l |
acc. RIPPEN, 1992 |
Wheat |
35-70% effect at 4.3 mg/l |
acc. RIPPEN, 1992 |
Characteristic effects:
Humans/mammals: The acute toxicity of atrazine for mammals is very low. In addition, there is hardly any resorption via the skin due to its low solubility. Atrazine does not irritate the skin or the eyes. It is easily resorbed after oral intake and within 24 hours, more than 50% is excreted via urine. During the passage, atrazine is completely metabolised mainly by way of oxidative dealkylation of the amino group and reaction of the chlorine atom with endogenic thiolic reagents. In animal experiments, mutagenic or teratogenic effects have not been discovered. Thus, in Germany, the substance is not classed as toxic.
ENVIRONMENTAL BEHAVIOUR
Soil:
The substance is characterised by a relatively high resistance to physical and
chemical transformation. In addition, the low solubility in water and the low vapour
pressure indicate a reduced mobility. Atrazine may be chemically hydrolysed forming the
inactive hydroxyatrazine which in turn may be microbiologically decomposed. The half-life
for hydrolysis is strongly dependent on the pH of the soil. In a neutral, slightly
alkaline or slightly acid environment, atrazine is stable (half-life at pH 7-9: 10,000
days). Hydrolysis mainly takes place under alkaline or acid conditions (half-life at pH 3
or pH 11 » 3 months) [acc. KOCH, 1989].
Water:
Although atrazine is very stable and only slightly soluble in water, the contamination of
groundwater has to be considered. In Germany, atrazine is classified in water hazard class
2.
ENVIRONMENTAL STANDARDS
| Medium/ acceptor |
Sector | Country/organ. | Status | Value | Cat. | Remarks | Source |
| Soil: | NL | G |
0.05 m g/kg | Reference | acc. TERRA TECH, 6/94 | ||
| NL | L |
6 mg/kg | Intervention | acc. TERRA TECH, 6/94 | |||
| Water: | Drinkw | D | L |
0.1 µg/l | single substance | acc. KOCH, 1989 | |
| Drinkw | D | L |
0.5 µg/l | sum of pesticides | acc. KOCH, 1989 | ||
| Drinkw | EC | L |
0.1 µg/l | single substance | |||
| Groundw | NL | G |
0.0075 µg/l | Reference | acc. TERRA TECH, 6/94 | ||
| Groundw | NL | L |
150 µg /l | Intervention | acc. TERRA TECH, 6/94 | ||
| Air: | Workp | D | L |
2 mg/m3 | MAK | acc. RIPPEN, 1992 | |
| Workp | SU | (L) |
2 mg/m3 | PDK | acc. AUER TECHNIKUM, 1988 | ||
| Workp | USA | (L) |
5 mg/m3 | TWA | acc. RIPPEN, 1992 | ||
| Foodstuffs: | |||||||
| Mushrooms | D | L |
10 mg/kg | acc. PERKOW, 1985 | |||
| Vegetable Corn | D | L |
1 mg/kg | acc. PERKOW, 1985 | |||
| Corn | D | L |
0.5 mg/kg | acc. PERKOW, 1985 | |||
| Vegetables | D | L |
0.1 mg/kg | acc. PERKOW, 1985 | |||
| Asparagus | CH | L |
1 mg/kg | acc. PERKOW, 1985 | |||
| Corn | CH | L |
0.1 mg/kg | acc. PERKOW, 1985 | |||
Assessment/comments
Because of its persistence and the hazard of contamination of groundwater and drinking water, the use of atrazine should be restricted as far as possible.