The siren is owned by Solvay Solutions which produces phosphorus-based intermediates used in the manufacture of pharmaceuticals, paints, detergents, and other products.
Designed to be heard up to one kilometre away, it exists to alert people in the area in the unlikely event of a major fire or chemical release from the Trinity Street site.
However, that won't be the case on Friday when the alarm on top of one a building in Trinity Street is sounded for 60 seconds at midday when the annual test is carried out.
The company is re-assuring people there is no need for anyone to take action when they hear the siren.
Solvay will have a telephone hotline available on 0121 552 3333 for neighbours to call if they have any questions or concerns.
Ian Fryer, Site Director, said: “We work closely with local authorities, the Health and Safety Executive and the emergency services to ensure that we are maintaining the highest standards of health, safety and environmental protection.
“However, in the unlikely event of an incident occurring on the site, it is important that we have an efficient and clearly understood way of alerting our neighbours. The off-site alarm is designed for that purpose and we test it annually in line with relevant legislation.”
The testing of such alarms is a requirement under health and safety legislation, and become an annual exercise in Oldbury.
Solvay also sends out information to nearby residents and businesses every two years, reminding them of what they should do if there's a fire or chemical release from the site.
If the alarm is sounded outside of the scheduled test dates, people nearby are advised to:
Go indoors, close all windows and doors
Cooperate fully with instructions from the emergency services
Wait indoors until the all clear message is given