Colin Souter, joint managing director of ABI Scientific, said he had received enquiries from a wide range of organisations.
He said: "The only way to be sure that you are safe is either not to drink at all or to use an accurate device like the ABI."
John Denham, head of Essex contractor John Denham Builders, said he had bought the device because of the dangers that alcohol poses on sites. He said: "It is able to give us a reading in a few seconds, which we can then act on to help reduce the likelihood of accidents."
Essex Roofing managing director Andre Looms said the device could be used as soon as there was any suspicion that an employee had consumed too much alcohol.
He said: "If we suspect that an employee or contractor is unfit to work because of drink we can now confirm it and act accordingly."