The crews extinguished the fire in Park Street, where the Betts metal company works were engulfed in flames last Wednesday.
The blaze was said to be small and a senior firefighter made a statement at the scene to reassure residents the situation was under control.
Today Jon Laight, Group Commander at Hereford and Worcester Fire and Rescue Service, said: "This type of small fire that has now been extinguished is common for these type of large incidents.
"We have a crew here applying water to the surrounding area.
"We are now checking it with thermal imaging cameras to check there are no further hotspots.
"This is not a recurrence of the major incident that happened last week. All is under control from our point of view.
"Please don't worry about our presence - we will be here just a little while longer checking with our thermal imaging cameras."
Clouds of black smoke could be seen 10 to 15 miles away across the Black Country during last week's blaze at 3pm which forced the closure of Park Street with Park Lane and Castle Street, as well as Bewdley Road by Kidderminster Hospital during the incident.
Nobody was injured but witnesses reported "running for their lives" and numerous schools and businesses had to be closed due to the blaze.