The blast at the Stockline factory in Maryhill, Glasgow, on May 11 2004 killed nine people and seriously injured 33 others. A build-up of leak ing gas from corroded underground pipes was to blame.
ICL Plastics Ltd and subsidiary ICL Tech Ltd were each fined £200,000 following an inquiry but Marie Murray, who lost her husband Kenny, 45, said the families have paid an "immeasurable" price.
Victims of the disaster will be remembered at a memorial at Maryhill Community Central Halls on Sunday afternoon.
Mrs Murray said: "Kenny left the house to go to work and never returned. You hear about this happening to other families but that day it happened to ours.
"Because of the tragedy, I lost my husband, my two daughters and son lost their dad, and he was robbed of the chance to see them grow up and his two grandchildren born."
Lord Gill led the public inquiry into the blast in 2009 and ruled that it had been an "avoidable disaster". He said that employers at the factory had not identified or understood workplace risks.
The £1 million investigation that followed the blast was the biggest of its kind ever undertaken by the Scottish authorities and involved a fingertip examination of more than 5,000 tons of rubble.
The UK Government later announced measures to strengthen gas safety on industrial sites.