About Us Substance Diagnostics Ltd is a national provider of drug and alcohol testing products. With over 20 years of combined industry experience, we guarantee we'll find the correct impairment solution to meet your demands. We appreciate that employee drug and alcohol screening can be a sensitive matter and can customize our services to meet your requirements. We will supply the best products for your needs and offer servicing, calibration and technical advice on request. We have a strong, highly trained Sales and Technical team who can be easily contacted when required. We pride ourselves on customer satisfaction and firmly believe our customer aftercare is second to none. Substance Diagnostics provide drug and alcohol testing advice and products for industry, home, sporting events and many other applications.