Why PPE are impartant before starting the work?

because it protects the workers form getting harmed  by falling objects, tripping , slipping on a wet floor etc.  

because it provides the minimum immediate protection

personal protective missions as the last line of defense to protect workers from injury factors which may be exposed to him because of the work they do and the conditione bbeing the way of additional and complementary protective group procedures and precautions taken to secure and protect workers exposed to risk of accidents at work   

Making the workplace safe includes providing instructions, procedures, training and supervision to encourage people to work safely and responsibly.

Even where engineering controls and safe systems of work have been applied, some hazards might remain. These include injuries to:

• the lungs, eg from breathing in contaminated air
• the head and feet, eg from falling materials
• the eyes, eg from flying particles or splashes of corrosive liquids
• the skin, eg from contact with corrosive materials
• the body, eg from extremes of heat or cold