Johannesburg - About 5 000 members of a chemicals and energy union were on strike on Tuesday over a salary dispute, their union said.
"Today more than 5 000 members of the Chemical, Energy, Paper, Printing, Wood and Allied Workers' Union (Ceppwawu) are striking in support of their wage demands in the metal, engineering and plastic industries," said chief negotiator Clement Chitja.
Their jobs include work in the plastic industry, blow-moulding, manufacturing carrier bags, electrical appliances, electrical sockets, car and machinery components.
Their members would gather at places in industrial areas where they would protest and march and wait for news on negotiations.
On Sunday, the Labour Court dismissed an application for an interdict to stop the strike, brought by employer body the Plastic Convertors' Association.
The application was opposed by Ceppwawu, the National Union of Metalworkers of SA (Numsa) and the Metal and Engineering Industry Bargaining Council (MEIBC).
The Plastic Convertors' Association is not part of the MEIBC, but falls under its jurisdiction.
The court ruled that all employees - including those of employers which are not part of the MEIBC - and non-members had a right to strike and join Ceppwawu and Numsa, whose engineering sector is also on strike.
As a result, Ceppwawu would mobilise not only its own members to strike, but also the thousands of non-union members.
It said the wage demands at the centre of the strike, once agreed on, would apply to all employees, irrespective of union membership.
The union wants a 13% salary increase on the grounds of rising daily costs.
"Employed workers are facing extreme pressures on their meagre wages where, for example, electricity only recently increased by more than 30%, coming on top of the 25% increase of last year."
Their other demands include: a total ban on labour brokers; family responsibility leave to be extended to five days per occurrence; shift allowance of 20% for night shift workers; 12 months' notice of change of technology to prepare for potential redundancies; and demands relating to permitted union activity.