Global alternative asset manager The Carlyle Group has acquired a majority stake in IsoMetrix, a South Africa-based environmental, health, and safety software provider. IsoMetrix plans to collaborate with another recent Carlyle acquisition, the South Africa-based occupational health and safety solutions provider NOSA, though the companies will continue to operate independently. Carlyle invested through its Carlyle Sub-Saharan Africa Fund. Financial details of the transaction were not disclosed.