THE Philippine National Police affirmed the findings of the Manila Police District, which concluded that the milk tea victims had ingested “oxalic acid,” but it could not say yet that the poisonous substance caused their death until another examination is conducted.
Chief Superintendent Theresa Ann Cid, PNP Crime Laboratory director, said the blood samples and gastric contents of William Abrigo, owner of ErgoCha milk tea shop in Manila, and customer Suzaine Dagohoy were tested positive for oxalic acid, a substance commonly used as bleaching agent.
Oxalic acid
But Cid said in an interview on Monday that the results of the toxicology exam were still inconclusive pending the histopathological examination, which would take a month.
“The cause of death can be known after the result of the histopathological examination which is part of the autopsy that actually requires a month for the completion of the examination,” she said.
Abrigo and Dagohoy died last April 9 after taking a sip of the “Hokkaido”-flavored milk tea Abrigo prepared himself.
READ: Milk tea deaths: Shop owner hits raps vs son; MPD cites ‘oxalic acid’
Meanwhile, the medical certificate of Dagohoy’s boyfriend Arnold Aydalla, who took a sip of the milk tea but survived after receiving treatment in the hospital, stated that he was diagnosed to have “toxic ingestion of unknown substance.”
In the Know: Oxalic acid
OXALIC acid, also known as ethanedioic acid, is a colorless crystalline widely used as a bleaching or cleaning agent. It is a toxic ogranic compound with the formula C2H2O4.
It is a known constituent of wood sorrel as early as 17th century. In 1776, it was prepared synthetically for the first time.
Oxalic acid may be present in some anti-rust products, bleaches, metal cleaners and rhubarb leaves.
The symptoms of poisoning from swallowing oxalic acid include abdominal pains, burns and blisters where the acid contacted the skin, collapse, convulsions, kidney problems, low blood pressure, mouth pain, shock, throat pain, vomiting and weak pulse.
According to US National Library of Medicine, oxalic acid poisoning may cause severe damage to the mouth, gastrointestinal tract or airway and quick death if a patient is not treated. Inquirer Research/AC
Sources: www.britannica.com, www.nlm.nih.gov
MPD director Chief Superintendent Rolando Nana said the milk tea, Hokkaido-flavored powder and syrup that the MPD recovered from the crime scene were also found to be positive for oxalic acid after the examination conducted by the Chempro Analytical Services Laboratories, Inc., a private laboratory analyzing various types of samples, through the Food and Drugs Administration.
Cid said oxalic acid is a corrosive powder used as bleaching agent and stain remover. Once dissolved in water, Cid said it cannot be cannot be easily determined as it is a colorless substance.
“About 10 µg/mL (micrograms per milliliter) of oxalic acid is considered dangerous amount. The average human body contains approximately four liters of blood, therefore, it will only take about 40 mg of oxalic acid to poison a human,” she said.
Cid added that the amount of oxalic acid found in the victims’ samples exceeded the lethal dose of the acid.
Earlier the MPD declared the milk tea case closed after it gathered sufficient evidence to file two counts of murder and frustrated murder against Lloyd Abrigo, son of the late ErgoCha owner.
As seen on the closed circuit television camera footage of the shop, Abrigo arrived at the shop the night before the incident and prepared a concoction. Shop helper Joseph Garnacio said Lloyd allegedly brought a foul-smelling chemical that night.
After the incident, Lloyd went back to the shop where he allegedly asked Garnacio to wash drinking glasses and other utensils.
However, the MPD said it has not established yet the motive behind the poisoning incident. AC