DCMU

• 3 - (3,4 -dichlorophenyl) -1,1- dimethylurea
• Diuron ®

Colorless crystalline solid

Fixed

158-159 ° C

Decomposition at> 200 ° C.

0.0011 MPa ( 25 ° C)

Practically insoluble in water (35 mg · l-1 at 20 ° C)

Attention

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DCMU is a derivative of phenylurea, which is used as herbicide and inhibiting photosynthesis of plants.

It was introduced in 1954 by the company Bayer under the trade name diuron as weed control agent and is used for the total elimination of plants ( broad-spectrum herbicide ). It is used for protecting wood and masonry and as the coating agent.

Effect

DCMU is a selective herbicide which has systemic properties. It is mainly absorbed by the roots of the treated weeds and transported therein, so that there is an enhancement in the upper parts of the plants. The drug inhibits plant photosynthesis by inhibiting the electron transport between photosystem II and plastoquinone (PQ ). Thus, the electrons move from the water splitting not to photosystem I (P700 ). So that the electron transport chain is interrupted based on the transport of electrons through the electron transport chain of photosystem II to photosystem I. The effect is measurable in mind that the chlorophyll of plants show an increased fluorescence. The cause of the fluorescence is that the absorbed light energy can not be implemented through the normal way of the linear electron transport in chemical energy. The cyclic electron transport (PSI to ferredoxin to cytochrome b6f to PQ complex to PC to PSI), however, is not affected.

Use

DCMU is selectively used for weed control in sugar cane, corn and cotton as well as in the wine, among ornamental trees and fruit trees. It is also used ( in higher doses ) in combination with other herbicides as a total and semi- total herbicide on paths and squares. DCMU is listed in Annex I to Directive 91/414/EC plant protection and thus in Europe an approved active substance.

In addition, it is used in material protection. Produced from DCMU - based paints coatings, eg Facade coatings or ship bottom paints ( antifouling paints ) to stay clear of algae. However, diuron is not effective against other fouling organisms ( crustaceans).

Toxicity

DCMU is classified as very aquatic environment.

The German railway put a diuron to 1996 to keep track systems plant free. After the suspicion had arisen, the agent could damage in high concentrations unborn and young children, the company renounced its application. With the Plant Protection Regulation application this application is also forbidden by law. Based on a study by the Federal Biological Research Centre for Agriculture and Forestry and the Federal Environment Agency reviewed in mid-2000 a relaxation of the feed ban. As an effective alternative was missing, it came in the meantime to increased weediness of track systems.

The Federal Ministry of Food, Agriculture and Consumer Protection (BMELV ) planned in 2002 in its draft amendment to the Plant Protection Regulation application even further limitation of use. A study by the Institute Fresenius, however, considers it only under unfavorable conditions possible that DCMU can reach the groundwater. DCMU is possibly carcinogenic.

The effects of DCMU on human health and the environment are tested under REACH in 2014 under substance evaluation of Finland.