Document O104gB0vLQgxY6raMNJVLq2dL

power sprayers it is advisable to use an ap proved respirator if considerable spray kicks back into tbe operator's breathing zone See Industrial Data Sheet 303 and Hygiemc Guide Decaborane--see Boron hydndes Dems is a powdered plant root, which con tains rotenone as its main active ingredient See Rotenone. Diacetone alcohol is a flammable solvent Exposure of laboratory animals to the satu rated vapor, 2100 ppm, resulted in irritation of the eyes, running of the nose, excitement, and then sleepiness m about 20 minutes There are no cases of human poisoning on record This solvent is liable to be a fire hazard because the commercial material often con tains acetone as an impurity in concentra tion great enough to substantially lower the flash point Diatomaceous earth is a form of silica m the amorphous state Although it apparently is . not as active m producing silicosis as its high content of free silica would lead one to expect, there have been a number of reports of silicosis from handling the material where the dust concentrations were high (see Chap ter 41, "Industrial Hygiene") If the temperature is raised to about 1,000 F (538 C) in a calcining operation, the ma terial readily changes to cnstobahte, which is a vigorous producer of silicosis It should be handled with the same precautions against dust used with other forms of free silica See Industrial Data Sheet 531 Diborane--see Boron hydndes. Also see Hygienic Guide 1,2-Dibromoethane (ethylene dibromide) is used mainly as a constituent of fumiga tion mixtures and of "leaded" gasoline To a limited extent, it has also been used as a fire extinguishing agent and solvent As an industrial hazard, it is toxic by ingestion, by skin contact, and by inhalation On expenmental animals it produces local tmtation of the eyes and skin if applied di rectly, but produces severe bums and is ab sorbed through the skin if it is confined in contact On ingestion and inhalation, it injures the lungs, liver, and kidneys and de presses the central nervous system Dichlorobenzene occurs as the three iso mers ortho, meta, and para All are flam mable liquids with low vapor pressures, but they are sufficiently volatile to produce toxic symptoms if handled in the open in a con fined area They are used primarily as in secticides, as intermediates in the dye indus try, and to some extent as solvents Development of cataract and of liver symp toms from chronic exposure to these com pounds in industry has been reported See Hygienic Guide Dichlorodifluoromethane (Refrigerant 12) is about as physiologically inert a substance as one could find It has no real toxic effects until the concentration becomes high enough to reduce the oxygen content of the atmos phere Since it is a refrigerant gas normally under fairly high pressure, it will freeze tis sue upon which it is directed It may also decompose if brought into contact with an open flame or a red-hot surface and produce irritating and toxic decomposition products 1.1- DichIoroethane (ethyhdene chloride) was formerly used as an inhalation anesthetic but has been completely displaced by safer materials It is still used to some extent as a solvent in industry Its acute effect is that of an anestetic and narcotic, and chronically it characteristically produces symptoms and signs of digestive and central nervous system irritations 1.2- Dichloroethane (ethylene dichlonde) is a commonly used, low-boiling solvent Qualitatively, its effects 'are very similar to those of 1,1-dichloroethane See Hygienic Guide 1.2- Dichloroethylene (acetylene dichlo nde) is a widely used solvent of low fire haz ard and relatively low toxicity It is a rather sweet-smelling narcotic somewhat like chlor oform both in odor and in effects, so that there is no adequate warning m the odor It can be detected by odor at 250 to 300 ppm For short exposures, it has no effect on men at 800 ppm and is not thought to have any spe cial chronic effects Dichloroethyl ether is used mainly as a dewaxing solvent It has a pungent, very irritating odor and is mainly an injurant of 1343