Atrazine

1912-24-9

Active ingredient in herbicides. 
Most widely used chemical for
pre-emergence weed control in corn. 
In Hawaii it is important
to the culture of sugarcane, pineapple, and macadamia nut.

Colourless crystals.

215.72

Equilibrium distribution:
        mass %
air      0.01
water   93.15
solid    6.84
(Anon 1988).

Theoretical distribution:
sediment and soil   32 %;
water               68 % (Nordic 1988).

Photochemical degradation in UV-light (254 nm): in water
solution Cl is changed with OH group (Esser et al. 1975).

Hydrolysis, pH 5, half-life: 64 d; pH 7 - 9, half-life > 200 d
(Burkhard & Guth 1981).

Hydrolysis: Cl breaks away , hydroxy derivatives are formed in
sterile soil (Esser et al. 1975).

75 - 100 % disappearance from soils in 10 months (Verschueren
1983).


In submerged soils: in 90 days 0.005 % of atrazine-14C was
recovered as 14CO2 (from ring labeled atrizine).

48 % to 85 % of atrazine was hydrolyzed in 30 days, depending
upon soil type.

Chemical hydrolysis of atrazine to hydroxyatrazine is the
principal pathway of detoxication in soil. 
Biological
dealkylation without dehalogination occurs simultaneously
leading to 2-chloro-4-amino-6-isopropylamino-s-triazine
(Goswami & Green 1971).

Aerobic degradation: OECD screening, 28 d, 9 %; closed bottle, 28
d, 13 % (Rippen 1988).

In surface water, pH 3.8 - 8.1, 30 d, no degradation (Wolfe
1980).

Half-life (total degradation) in 10 years (Dawson et al. 1980). 
Phytotoxic persistency: 1 - 3 years (Torstensson 1988).

Anaerobic bacteria eliminates original chemical in < 1 day
(Jessee et al. 1983).

Hydroxyatrazine is the main product of chemical hydrolysis
in soil (Goswami & Green 1971).

No biomagnification in a model ecosystem (Klaasen & Kadoum 1979).

Bioconcentration factor (mollusca):
3.7, mollusca, (Gunkel & Streit 1980).

Bioconcentration factor (algae):
10 - 83, algae (Verschueren 1983).

Bioconcentration factor (other):
2 - 15, snails (Verschueren 1983).

In diet: when fed for 2 years to rats at dietary levels of 100
and 1000 ppm, no effect was observed (Martin 1968).

NOEL, 28 d, < 30 mg/kg, orl, rat (Rippen 1988).

No embryotoxic effect , 1000 mg/kg in birth (Rippen 1988).

Negative Ames test and DNA reparation test (Rippen 1988).

Teratogenic effect in fish (Birge et al. 1981).

0.1 mg atrazine/kg soil decreased oat biomass weight by 27.5 %. 
The phytotoxic limiting concentration of atrazine was
established as 0.01 mg/kg (Ladonin & Lunev 1983).

Lamb's -quarters (Chenopodium album) were killed completely
when atrazine was applied with a sprayer at 1.12 kg/ha as
preplant incorporation or preemergence or postemergence
(Bandeen & McLaren 1976).

Avena sativa, EC50, 0.001 mg/kg, TS substrate (Rudoph & Boje
1988).

Bacteria: Pseudomonas putida: inhibition of cell multiplication
starts at > 10 mg/l (Bringmann & Kühn 1976).

Algae; 0.018 mg/l, 12 days; population growth effect (change in
cell number of algae species including pre-exponential lag rate
effects) (Hamilton et al. 1987).

Phaeodactylum tricornutum: 0.015 mg/l, 7 days; growth effect
(measurable change in length and/or weight) (Mayasich et al.
1987).

Effect on rate of colonization:
Algae, 12 d, 0.024 - 0.134 mg/l (Krieger et al. 1988);
aquatic community, 3 - 21 d, 0.0032 mg/l (Pratt et al. 1988);
Protozoa, 3 - 21 d, 0.0032 mg/l (Pratt et al. 1988).

Chlamydomonas reinhardtii:
1 - 2 d, 0.216 mg/l, lethal effect;
1 - 2 d, 0.0216 mg/l, change in cell number (Hersh & Crumpton
1987).

Lepomis macrochirus, 136 d, 0.020 mg/l, effect on food
consumption rate and reproduction (Kettle et al. 1987).

Algae: Microcystis aeruginosa: inhibition of cell
multiplication starts at 0.003 mg/l (Bringmann & Kühn 1976).

Algae:
Chlorococcum sp. 
(technical acid): 100 ppb:
50 % decrease in O2 evolution
50 % decrease in growth; measured as ABS (525 mu) after 10 days

Dunaliella tertiolecta (technical acid): 300 ppb:
50 % decrease in O2 evolution
50 % decrease in growth; measured as ABS (525 mu) after 10 days

Isochrysis galbana (technical acid): 100 ppb:
50 % decrease in O2 evolution
50 % decrease in growth; measured as ABS (525 mu) after 10 days

Phaeodactylum tricornutum (technical acid): 100 ppb:
50 % decrease in O2 evolution

Phaeodactylum tricornutum (technical acid): 200 ppb:
50 % decrease in growth; measured as ABS (525 mu) after 10 days
(Walsh 1972).

Periphyton ecosystem, inhibited production, 0.08 mg/l (Hamilton
et al. 1987).

Lemna minor, LC100, 27 d, 0.12 mg/l (Gunkel 1983).

Not allowed to use in Sweden from 1.1.1990 (Anon. 1989).