Tests are being carried out on samples from a factory's cooling towers and air conditioning units after a man died in the latest outbreak of Legionnaires' disease.
Scientists are analysing water samples from around 20 cooling towers and air conditioning units at Rhodia Consumer Specialities in Oldbury, where two of the seven victims worked.
The firm says officials from the Health and Safety Executive (HSE) have visited the plant three times since the outbreak started.
The visit was part of an HSE inspection of around 40 such towers and air conditioning units in the Oldbury and Smethwick areas.
One of those infected - 63-year-old Barry Humphries, of Cannock, Staffordshire - is a delivery driver who visits and works at the plant regularly. He is recovering at Staffordshire General Hospital.