A woman has been charged after allegedly poisoning a co-worker's lunch curry with snail pellets.
WA Police say a 58-year-old woman brought a container of curry to share with colleagues at her workplace in Perth's southern suburbs in February.
A 43-year-old woman allegedly contaminated it with snail pellets containing metaldehyde, a poisonous substance, a spokesman said on Thursday.
"The curry had been shared among employees and consumed without issue during a morning tea break," police said.
"After the meal, the accused accessed a chemical storage shed and later entered the staff lunch room where the food was kept."
At lunchtime, the alleged victim went to eat some more of her curry.
When she opened the container, she spotted bright green granules in the food.
"After tasting a small amount, (she) experienced numbness to her tongue," the police spokesman said.
It will be alleged the accused and the victim were in a personal relationship.
Detectives arrested the 43-year-old woman last week.
She has been charged with one count of unlawful act or omission with intent to harm (endangering the life, health or safety of any person).
She is scheduled to appear before Armadale Magistrates Court on November 5.
Police declined to provide further information about the relationship or the workplace.