Observation

The question was unpopular among the candidates and the overall performance on the question was below average. Most candidates were unable to  define  chlorine and oxygen bleaching,  and also lack thorough knowledge of materials for bleaching. The candidates did not understand the content of this topic.  They were expected to respond to the question in the following manner:

(a) (i)        Definition of chlorine bleaching
It is a toxic, gaseous and liquid chemical element used as an agent for whitening or removal of the natural colour of textile fibres, yarns and fabrics for decorations and designs.                                                                                                                                                                                       
(ii)       Definition of oxygen bleaching
It is a colourless, odourless and powdered chemical substance used as an agent for whitening or removal of the natural colour of textile fibres, yarns and fabrics for decorations and designs.                                                                         
(b)            Materials for bleaching:
Fabric/Cloth; Soap/Detergent; Water; Pomade/Petroleum jelly; Chemicals/Bleaching agents (e.g Caustic soda; hydrosulphite, turpentine; chlorine; hydrogen peroxide, etc), Motif/Stencil; Pencil/Chalk; Thread/Twine; Rag; Foam; Masking tape/Cellotape.

(c)             Ways to avoid hazards during bleaching:

• Wear safety/rain/industrial boots.
• Wear nose and mouth mask/guard.
• Wear rubber/hand gloves.
• Wear apron/overall.
• Wear safety glasses/sunshade/goggles.
• Avoid distraction or fatigue.