A man with learning difficulties died and five others suffered agonising internal injuries after confusing dishwasher fluid with orange squash and drinking it on a council-organised trip.
East Sussex County Council was prosecuted by the Health and Safety Executive (HSE) following the incident on 7 December 2004.
The adults from St Nicholas Centre, Lewes, were on a visit to Plumpton Agricultural College to use the sporting facilities. The drink, which should have been orange squash but which actually contained the powerful chemical sodium hydroxide, had been prepared at the day centre and taken with them.
Lewes Crown Court heard how the six immediately became distressed, started vomiting blood and began fitting after swallowing the industrial cleaning chemical.
Colin Woods, 60, who had Down's syndrome, died on 5 April 2006 - 17 months after sustaining his initial injuries. Other members of the group suffered burns to their mouths, throats and stomachs and most had to undergo repeated surgery. Three will never be able to swallow normally again.
The HSE investigation found the council had failed to ensure the dishwasher fluid was safely locked away. It admitted leaving the liquid out in the unlocked kitchen of the day centre.
Although the dishwasher fluid was marked as corrosive, its container was similar in appearance to that of the orange squash.
The court heard that surviving service users were considered too traumatised by the incident to be interviewed about who mixed the drink.
HSE inspector, Andrew Cousins, said:
"This is one of the worst incidents I have investigated in all my time as a health and safety inspector - it is impossible to adequately imagine the suffering and terror that the victims must have felt as this tragedy unfolded.
"The terrible thing is that this incident and its horrific consequences could so easily have been prevented by simply locking away the container of sodium hydroxide.
"Instead, Mr Woods died a slow, painful and unnecessary death and others have suffered terrible, preventable injuries - some painful and permanent - because the council failed in its responsibility to take proper care of them. It is imperative that authorities properly protect vulnerable people in their care."
East Sussex County Council, of County Hall, St Anne's Crescent, Lewes, East Sussex, pleaded guilty to breaching section 3(1) of the Health and Safety at Work etc Act 1974. Today, the council was fined £50,000 and ordered to pay costs of £27,670.
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Issued on behalf of the Health and Safety Executive by COI News & PR South East
Regional reporters should call the appropriate Regional News Network press office who act as HSE's Press Office throughout Great Britain.
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