When changing product from one drink to another, the lines have to be cleaned and sterilised. A SIP clean was the process used to keep the drink production system clean.
The normal chemical they used was a proprietary cleaner called "Solchlor" a mixture of Caustic Soda and Sodium Hypochlorite (bleach). They ran out of the pre-mix soloution several weeks before, instead opting to mix their own by ordering the chemicals seperately. As the mixing machine was broken the process was carried out in open containers. Despite a couple of unreported near-misses, this cheap shortcut had become the norm.
On the day of Ken's accident he was asked at the end of his shift to carry out the SIP clean. He had never done this before, but was prepared to help his boss and make sure the day shift didn't have to do it. Although experienced staff were around, there was that feeling of anxiety to get home as the end of the shift drew closer.
Ken tried to find the appropriate personal protective equipment (PPE) (a chemical suit and eye goggles) but there was nothing available. He later found out that the chemical suit was in such a poor condition it would have been unusable anyway.
When the two chemicals were mixed together there was an instantaneous violent reaction that flew in to Ken's face - just 18 inches away from the explosion. The reaction was so extreme it hit the 70ft high factory ceiling. His life was saved by his colleagues who manhandled him into a nearby emergency shower and held him in while he struggled to get out.
The last person Ken would ever see was his friend and manager Grahame Norris.
Ken was severely burned and eventually it was confirmed that he had lost his sight (his eyes had to be removed), his sense of smell and sense of taste (absent, except from the occasional really strong curry). He had just got engaged to Sue and offered her the chance to leave rather than be stuck with him. Thankfully, she decided to stay.