2-CHL,ORO-N, N-DIALLYLACETAMIDE [CDAA] 



CDAA is formulated as an emulsifiable concentrate. It has shown promise 

 for pre-emergence control of weed grasses in soybeans, corn, and in certain 

 other crops. CDAA is less effective on broadleaved weeds than on grasses. It 

 often causes sonne tenaporary stunting of broadleaved w^eeds w^hich opens the 

 way to more effective control by timely cultivation. CDAA may cause serious 

 irritation to the eyes . This hazard can be reduced by wearing goggles and 

 rubber gloves during application. 



CDAA has an intermediate oral toxicity (L1D50 = 700 mg./kg.) for rats. 



METHYL BROMIDE 



Methyl bromide applied at heavy rates as a volatile soil fumigant ■will kill 

 most weed seeds and plants. It has a boiling point of 38° F., and is sold in 

 sealed cans as a liquid under pressure. When released at 68° F., it beconnes 

 a gas 3.2 times heavier than air. The gas must be released under an airtight 

 cover for use as a soil fumigant. Confining the gas under an airtight cover 

 for 24 hours is usually sufficient for weed control if soil in the treated area 

 is moist and has been loosened to aid gas penetration. It is safe to plant 

 crops 2 to 3 days after the airtight cover is removed. Methyl bromide is 

 poisonous to man and aninnals. Effects of exposures within a 24-hour period 

 are cumulative. Skin contact can produce severe burns. The gas is colorless 

 with a slight, sweetish odor. Warning traces of other gases, such as 

 chloropicrin, are usually added to increase safety in application. 



Methyl bromide is relatively toxic, being absorbed by the skin as well as 

 by inhalation. 



2, 3-DICHLORO- 1 , 4-NAPHTHOQUINONE [dichlone] 



Dichlone is available as a dry, w^ettable powder that disperses readily 

 in water. It is used for control of blue-green and green algae in lakes and 

 ponds. It mixes well with oil, is chemically stable, and, as an algicide, re- 

 mains active in Avater having a pH up to 10. 



Dichlone is relatively low in oral toxicity (LD^q = 1,500 mg./kg.) for rats. 



ACRYLALDEHYDE [acrolein] 



Acrolein is a highly reactive water-soluble chemical solution that has 

 proved very effective for controlling subnnersed aquatic weeds in irrigation 

 and drainage channels. The chemical is toxic to nnammals, and to fish and 

 other aquatic animal life. It is highly volatile, flammable, and its vapor is a 

 powerful irritant to the eyes and respiratory passages. Because of these 

 properties, the chemical must be metered or pumped from the closed con- 

 tainer into the water of the channel without contact with the air. 



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