Contaminants washed cotton

Emulsifiable concentrate formulation of diazinon, diluted to field strength (0.5% a.i.) was used to contaminate 100% cotton fabric.7 A single hot-water wash (60°C) results in 1% diazinon remaining on the cotton fabric. When cotton is contaminated with the concentrated (full-strength) diazinon (47.5%), and washed in hot water, 4% pesticide residue remains. 

When wettable powder formulation of iprodione was diluted to field strength (0.05% a.i.) and used to contaminate 100% cotton and 65/35 polyester/cotton fabric, it was found that a single warm water wash (50°C) left approximately 1% iprodione residues on the fabric.5... 

Foot exposure of workers can be measured by using socks as dosimeters or anklet dosimeters worn under ordinary socks. Usually an ordinary sock or anklet bought at a retail store will suffice for the dosimeter. As with whole-body dosimeters, the sock material should be 100% cotton but may be other materials. Pre-washing the socks or anklets prior to use in the field may be necessary if analytical interferences are found in the sock material. The socks or anklets should be put on the volunteer using procedures similar to those already described in order to avoid cross-contamination of the sock dosimeter. 

D amine or ester formulation was diluted to field strength (1.25% solution) and used to contaminate cotton denim fabric.6 The amine formulation is highly water soluble and is readily removed with a single wash it makes no difference whether a cool (30°C) or hot wash (60oC) is used. At both wash temperatures, less than 1% 2,4-D amine residue remains. 

Emulsifiable concentrate formulation of diazinon, diluted to 1.0% a.i. was used to contaminate a 50/50 blend of cotton and polyester. A single warm-water wash (49°C) results in approximately 4% diazinon remaining however, if the fabric is pretreated with Spray n Wash (a prewash commercial soil and stain remover containing a blend of... 

Emulsifiable concentrate formulation of Triallate, diluted to field strength concentration (1.8% a.i.), was used to contaminate cotton twill fabric. The best laundry procedure is to pretreat the work clothing with a pre-wash commercial soil and stain remover containing a blend of surfactants and solvents, launder in hot water (60°C), and then launder a second time. Approximately 18% of the pesticide remains in the fabric using the above procedure after a single wash when no pretreatment and warm water (50°C) were used, as much as 48% of the Triallate remained. 

Mild washing by the continuous batt system or a rayon rinse system is with water containing a wetting agent, at not less than 60°C, with water-to-fiber ratio not less than 40 1, with bacterial levels in the wash water controlled to limit bacterial contamination of the cotton. 

Several components of chlordane trans- and c/s-chlordane, trans- and c/s-nonachlor, heptachlor, gamma-chlordene) were detected in the skin lipids of humans (Sasaki et al. 1991b). The samples were taken by swabbing the face with cotton soaked with 70% ethanol 3-4 hours after the face was washed with soap. Because all samples from inhabitants of an area known to be contaminated with chlordane contained chlordane residues, and because the profile of chlordane components in skin lipids closely resembled those in technical chlordane, the authors suggested that skin lipid analysis is a satisfactory indicator of dermal exposure to airborne chlordane, such as occurs in homes treated for termites. Oxychlordane in the skin lipids was positively correlated (correlation coefficient = 0.68, p<0.01) with concentrations in internal adipose tissue. The authors concluded that the concentration of oxychlordane in skin lipids was a satisfactory indicator of body accumulation of chlordane. 

Transfer of the pesticide from contaminated fabric to clean cotton fabric through contamination of the washing equipment to subsequent laundry was also determined. 

Transfer of Contamination in Laundry. Sustained transfer occurred when a clean fabric was laundered in equipment that had been used to wash contaminated fabric. The transfer fabric was an all cotton batiste of plain weave construction. These fabric swatches (8x8 cm) were subjected to one complete laundering cycle immediately after the contaminated fabrics had been through one wash and two rinse cycles. 

That is, following completion of the laundering process, the contaminated denim fabric swatch was removed, the rinse water decanted, and a clean cotton transfer fabric added to each canister along with 150 ml of phosphate detergent solution. Warm water (49 C) was used for the wash and two rinse cycles. After laundering, the transfer fabric was air-dried and retained in glass for solvent extraction. 

Laboratory coats provide a protective layer of clothing between you and the hazard. If you are using flammable, pyrophoric, or other reactive chemicals, you should use fire-resistant lab coats. While lab coats made of 100% cotton or polyester/cotton blends offer some protection against splashes, spills, or contamination, these coats have little or no fire resistance. Laboratory coats made of Nomex , Indura , or Excel are principally made of 100% cotton combined with fire retardant threads and are fire resistant. (Alas, however, they don t come in white.) Washing does not remove their fire resistance. The importance of wearing a fire-resistant lab coat for some laboratory operations is illustrated by Incident 7.3.5.1. 

Amine filter elements that have been washed with surfactants or contaminated with oils during manufacture (e.g., string wound cartridge filters made with virgin cotton, but containing cottonseed fragments). 

Oven-dried cotton contains about 90% cellulose whilst cotton linters contain 80-85%. In the preparation of chemical cellulose, cotton linters are processed in the following manner. Firstly, the linters are heated at 130-180°C under pressure with 2-5% aqueous sodium hydroxide for 2-6 hours this treatment solubilizes particles of seed-hull and other contaminants present in the linters. The liquor is drained off. The residual linters are washed with water, bleached with gaseous chlorine or calcium hypochlorite, re-washed and dried at about 70°C. The final product has a cellulose content of about 99%. 

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