Flash was stored in an unlocked hospital cupboard just metres from the bed of a patient who died after drinking it from her water jug, an inquest heard.
Joan Blaber died six days after swallowing the branded floor cleaner while she was being treated in the Royal Sussex County Hospital in Brighton last year.
The 85-year-old, of Lewes, East Sussex, was admitted with a minor stroke on 22 August but her condition worsened after the incident on 17 September 17. She died on 23 September.
When the inquest resumed on Thursday, Brighton and Hove Coroner’s Court heard from Olga Thomasa, who was working overtime as a housekeeper on the day the liquid was discovered in a jug on Blaber’s bedside table.
She was tasked with cleaning the Baily ward – using Flash mixed with water on the floors – and also collecting water jugs, emptying and washing them before refilling and returning them to patients.
Blaber’s bed was near a cupboard where hazardous cleaning chemicals were stored, according to a diagram of the ward shown to jurors.
A container of Flash was normally kept in the cupboard on the floor. Even when diluted the smell of the detergent was “very strong”, Thomasa said.
Thomasa, a permanent member of staff for four years who started working at the hospital through agency Sodexo, told the inquest a security code was normally needed to open the cupboard.
She said: “On this particular day the cupboard was actually open. The cupboard [door] was closed but it wasn’t locked.
“I don’t usually work there [on that ward] so I have no idea if it was unusual or not.
“I did actually think that maybe because it was the weekend and nobody had the code, staff might have left it open.
“I wasn’t that worried about it. I’m sorry, I don’t know why. I think I could have called the supervisor and I should have in this case. I know better now.
“But on that day I wasn’t worried because nothing had ever happened like that before. But now I worry about it.”
Speaking of her “shock” at the incident, she added: “I just don’t know how it happened. I have no idea. I just don’t know how Flash got into a jug.”
The hospital had a system of using different types of water jugs to identify the needs of patients.
On that day, Blaber’s usual jug was replaced with one which was the wrong colour, the inquest previously heard.
But staff on the ward told how they were either unaware of the system, or a shortage of jugs prevented it being used. Spare water jugs were stored on shelves in a kitchen used by staff who were carrying out cleaning tasks, the court was told.
Blaber’s water jug – which relatives said was usually clear – was removed by Thomasa in the afternoon and when it was refilled and returned she was given a solid green one with the same colour lid instead, jurors were told.
This meant no-one could see the liquid inside.
Thomasa said patients were just given the jugs that were available, adding: “I remember just cleaning the jugs, filling them [with water] and putting them back on the trolley.”
She said her back would have been turned for only a matter of seconds while taking water jugs from a trolley and putting them by patients’ bedsides.
The jury has lost two members since the proceedings began on Monday and is now reduced to nine – six women and three men. One man was dismissed for researching the case despite being ordered not to and escaped without a fine. Another was released due to problems with arranging childcare.
The inquest, taking place at the Jury’s Inn hotel near Brighton Station, is expected to last eight days.