Reddening

By way of caution it should be noted that free alkali or the alkali salts of weak acids will redden the reagent like an aldehyde. It is also, of course, reddened by heat or when exposed in small quantities to the air for some time. Mineral acit greatly reduce the sensitivity of the test. 

For larger burns, or bums in which the skin is reddened or blistered, apply one per cent, sodium bicarbonate solution without delay, and call for medical aid at once. 

Health and Safety Factors. The following toxicides for acetonitrile have been reported oral LD q (lats), 3030—6500 mg/kg skin LD q (rabbits), 3884—7850 mg/kg and inhalation LC q (i ts), 7500—17,000 ppm (29). Humans can detect the odor of acetonitrile at 40 ppm. Exposure for 4 h at up to 80 ppm has not produced adverse effects. However, exposure for 4 h at 160 ppm results in reddening of the face and some temporary bronchial tightness. 

Acrolein vapor is highly irritating to the eyes, causing pain or discomfort in the eye, profuse lacrimation, involuntary blinking, and marked reddening of the conjunctiva. Splashes of Hquid acrolein will produce a severe injury to the eyeHds and conjunctiva and chemical bums of the cornea. 

Donoi—acceptoi chromogens in solution are often strongly affected by the nature of the solvent or the resinous substrate in which they are dissolved. The more polar the solvent or resin, the longer the wavelength of the fluorescent light emitted. Progressing from less polar to more polar solvents, the bathochromic, or reddening, effect of the solvents on the dye increases in the order of aUphatics < aromatics < esters < alcohols < amides. 

Soap as used in personal cleansing products has a long safe history of use. Modem soaps have been specifically formulated to be compatible with skin and to be used on a daily basis with minimal side effects. Excessive use of soap for skin cleansing can dismpt the natural barrier function of skin through the removal of skin oils and dismption of the Hpid bdayer in skin. This can result in imperfect desquamation or a dry appearance to skin and cause an irritation response or erythema, ie, reddening of the skin. Neither of these is a permanent response and the eHcitation of this type of skin reaction depends on the individual s skin type, the product formulation, and the frequency of use. 

Figure 3.21 As in Figs. 3.19 and 3.20, after several hours of exposure to air. Note the reddening.

TO. The material is slightly yellow and may redden on drying it probably contains a trace of 2,4-diamino-i-naphthol. 

LD50 (see Ch. 5), death occurring within 30 days. Erythema (reddening of skin) within 3 weeks. 

Solid Irritant Characteristics-. Represents a minimum hazard. If spilled on clothing and allowed to remain, may cause smarting and reddening of the skin Odor Threshold 40 ppm. 

Value)-. Not pertinent Short-Term Exposure Limits-. Not pertinent Toxicity by Ingestion Grade3 LDjo 50 to 500 mg/kg Late Toxicity Data not available Vapor (Gas) Irritant Characteristics Not pertinent Liquid or Solid Irritant Characteristics Minimum hazard. If spilled on clothing and allowed to remain, may cause smarting and reddening of the skin Odor Threshold Not pertinent. 

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