Four workers at Wood Treatment Ltd in Bosley, Cheshire, were unaccounted for after the 17 July blast.
Three people have since been identified after remains were discovered.
Kelvin Barks, whose brother Will, 51, was identified, said the fund would hopefully start paying out next week to families having financial hardship.
He said: "There's 50 people without jobs... so it's... small but it all helps.
"Thank you (to) everybody who has helped and is continuing to help."
Will Barks, Derek Moore, 62, and Dorothy Bailey, 62, have been identified as victims.
Other remains have been found. Jason Shingler, 38, is still missing.
The money has been raised through a website which was started by Kelvin Barks following the explosion.
The blast caused the collapse of a four-storey building.
Temperatures reached 1,000C and it was described by rescuers as the "worst incident of its kind" in a decade.
An investigation into the cause of the explosion continues.
For the last week search teams were pulled from the factory site as two silos that were unsafe had to be demolished.
But specialist search teams were back at work on Tuesday.
Wood was processed at the plant into a fine powder and the resulting "wood flour", with a consistency like sand, was used to make laminate flooring.
Families of people caught up in a fatal explosion at a wood flour mill say £50,000 has been raised for them and workers without jobs.