The family of a 21-year-old woman who died after taking an industrial substance which is marketed online as a slimming aid have called for tougher laws to regulate its sale.
Bethany Shipsey died last year after taking an overdose of the pills - it was Beth's 15th overdose but doctors did not consider her a suicide risk.
Worcestershire Coroner Geraint Williams recorded a narrative verdict, including a finding of suicide, after ruling that the care Miss Shipsey received at Worcestershire Royal Hospital had been "significantly substandard" and included several "basic" failings.
Doug and Carole Shipsey said they disagreed with the inquest verdict that their daughter Beth, who had a history of mental illness and self-harm, took her own life when she ingested a fatal dose of DNP.
They said the care she received in hospital on 15 February 2017 was substandard.
Mrs Shipsey said: "It was like we were invisible, it was like we were in the way. There was no sense of urgency around Beth.
"I just felt helpless and I didn’t know what to do,"
Mr Williams criticised hospital staff for failing to record observations and said a decision not to phone for advice from a poisons unit had been "naive and unjustified".
But Mr Williams ruled none of the failings were a cause of Miss Shipsey's death and that she probably would not have survived if she had been given different care.
Speaking after the inquest in Stourport-on-Severn, Mr Shipsey warned others to be cautious when buying any diet pills online and called for "proper and effective" controls on DNP.
Claiming his daughter, from Worcester, was shown no dignity in the last minutes of her life, Mr Shipsey said:
"In addition to the serious failings of the Worcestershire Royal Hospital, Beth's life was brutally cut short by the effects of the deadly industrial toxic substance DNP, which was illegally sold as a so-called diet pill.
"Beth was unlucky enough to be taken to an inadequate A&E department which was overcrowded, overwhelmed and under-staffed - literally a first world hospital in third world circumstances."
He added: "It's important that everyone knows that DNP is not actually a diet pill - it's a lethal industrial compound with no known antidote which is inserted into capsules and illegally sold over the internet.
"Beth was a wonderful young person with her whole life in front of her but Beth has been cruelly taken from us and from her world."
Michelle McKay, Chief Executive of NHS Worcestershire Acute Hospitals, has apologised for the failings in care and said improvements have been made since Bethany's death.