Chlorine bleaching conditions

Chemical Properties. Under slightly acidic or basic conditions at room temperature, acetate and triacetate fibers are resistant to chlorine bleach at the concentrations normally used in laundering. 

Solutions of available chlorine bleaches decompose on standing at a rate that depends on the conditions described below. Hypochlorous acid [7790-92-3] and hypochlorite anions decompose according to equations 6 and 7 (20,21) ... 

STABREX Stabilized Liquid Bromine9 is far more stable than liquid chlorine bleach. For example, several tons of the new product were shipped to India and stored for one year above 90 °F. The product remained within specification (less than 10% degraded) for the entire year, after which it was successfully used to control fouling in an industrial water system. Chlorine would have completely degraded in this time under these conditions. Chemical wastage was eliminated. Accident risk in transporting oxidant was reduced because less volume was necessary. Table 2 shows the stability of the new product compared to industrial strength chlorine bleach in well-controlled laboratory tests. 

Small Quantities. Ethidium bromide is normally used in very dilute aqueous solutions and under these conditions, it can be converted to the physiologically inactive product, 2-carboxybenzophenone, with chlorine bleach. Wear goggles and protective gloves and... 

Typical chemical and physical properties of these fibers have been discussed (68). In slightly acidic or basic conditions at room temperature, acetate and triacetate fibers are very resistant to chlorine bleach at the concentrations normally encountered in laundering (68). Acetate and triacetate fibers are not affected by the dry-cleaning solutions normally used in the United States and Canada, but triacetate is softened by trichloroethylene (68). Delustering can be accomplished by hot soap solutions (72) so caution needs to be applied during cleaning of acetate fabrics. The immediate cause of delustering by hot soap solutions is the... 

Decontamination of clothing, equipment, and the environment can be performed since T-2 toxin is sensitive to standard household bleach (soaking for 30 min) especially when the solution is alkalinized (Castegnaro et al., 1991 Madsen, 2001). For environmental decontamination, the use of a chlorine bleach solution under alkaline conditions such as 1% sodium hypochlorite (1 part bleach and 4 parts water) and 0.1 M sodiiun hydroxide solution with a 1 h contact time is recommended. Other trichothecenes should also be sensitive to this decontamination procediue. 

The commercial solution of sodium hypochlorite contains 14-15% available chlorine, compared to 35-36% in bleaching powder. The concentration of hypochlorite in the bleaching bath generally varies from 1 to 3 g/1 available chlorine. The optimum bleaching conditions, however, depend on the degree of discolouration of the cloth and thus the temperature and time of reaction should be adjusted according to the requirement. The concentration of hypochlorite solution is normally estimated by means of standard thiosulphate or arsenite titration. 

In addition to the hazards of heat and glass in the use of the autoclave, a special hazard deserves mention. Cellulose nitrate media such as centrifuge tubes or nitrocellulose filters can be highly reactive and can decompose explosively under the conditions of high heat and pressure present in autoclaves (82, 113). Therefore, never use the autoclave to decontaminate infectious materials present in these media instead, utilize chemical decontamination techniques. Soaking in a 10 percent aqueous chlorine bleach solution for 30 minutes has been recommended (82). 

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