The South African government has removed bans on five persons, including an American, who had been active in the black labor union movement.

The action appears to be taken in conjunction with the government's intention to revise its labor policies regarding blacks, with a view to eliminating racial discrimination in the work place.

A ban is an arbitrary restriction on an individual's movements and social contacts. It usually is imposed on persons who have violated no law but are deemed politically "dangerous" by the government because of their opposition to official racial policies. More than 100 persons remain under such restriction in South Africa.

Jean Tyacke, 51, of St. Paul, Minn., has lived in South Africa 20 years. She received word on Monday that the banning order against her had been lifted.

According to an American Embassy official, she was the only American banned in this country. The ban against her husband, Eric Tyacke, 54, a South African, also was lifted Monday. They were among about 30 persons, most of whom are white, who were banned in November 1976, apparently because they were helping blacks form labor unions.

Minister of Justice Alwyn Schlebusch said recently he was reviewing the banning orders in force, and these five unbannings are the first positive results of that review. On Aug. 22, however, Schlebusch imposed a five-year ban on an Indian laywer, Priscilla Jana, who has many clients involved in political trials. This would seem to indicate his readiness to use the banning machinery when he considers it necessary.

In the past, bannings have been used to hinder the growth of the black trade union movement.

"They never made black trade unions illegal," Jean Tyacke said today. "They just banned trade union leaders."

As far as foreign observers were concerned, "the removal of banning orders on individuals (active in trade unionism) has been regarded as an important test of the government's sincerity in moving away from discrimination in industrial relations," said one American source.

Already the government has scrapped laws that kept blacks out of certain jobs, and in May it accepted several recommendations -- including the legalization of black unions -- resulting from an extensive government study of black manpower headed by Nic Wiehahn.

While the government's acceptance of black unions was welcomed, there was widespread disillusionment because migratory workers were excluded from unions. Such workers make up a large part of South Africa's work force, and are the bulk of the membership in already existing black unions. These union will get no legal recognition unless they exclude migrant workers.The government rejected a recommendation to allow multiracial unions.

Some government critics fear that registration of black unions will bring them under strict government regimentation that, in the end, could render them less powerful than they are now.

Wiehahn received only lukewarm response from government and labor officials in Europe and the United States on a recent trip to explain the South African government's reforms. But Fanie Botha, minister of manpower utilization, says these reforms are only "the first step of renewal" that is to follow the Weihahn report. He also said he was taking another look at trade union rights for black migrant workers.

Jean Tyacke was born in St. Paul but grew up in Los Angeles, where she worked in trade unionism with the Congress of Industrial Organizations. She then lived for 10 years in Chicago, where she was actively involved in the young Christian Workers' Movement, which brought her to South Africa in 1959.

Until being banned three years ago, she worked at the Urban Training Project, a Johannesburg-based organization founded by her husband in 1971 to help black union organizers.