On 28/1, Vo Thi Thu Oanh, Tang Thi My Hoa (48), and Tang Hoang Vinh (43) were arrested by the Ho Chi Minh City Police's Economic Police Department for investigation into the illegal production and sale of toxic substances.

Vo Thi Thu Oanh (in black, left), Tang Thi My Hoa, and Tang Hoang Vinh. Photo: Ho Chi Minh City Police

Previously, in mid-December 2025, authorities inspected the Tan Da Dental Equipment store at the Ngo Quyen apartment building (An Dong ward, former District 5), which Hoa managed. There, police discovered 534 bottles of "Pate Necronerve" (pulp devitalizer) and 5 boxes of "Arsenic Blue 5g" without invoices or documentation.

Forensic analysis revealed that all these products contained over 674 grams of arsenic trioxide. This toxic substance is classified as a specially controlled chemical, capable of causing cancer and severe health hazards.

Expanding the investigation, police identified Vo Thi Thu Oanh as the source of the goods. She admitted to purchasing chemicals, then manually concocting, mixing, and packaging them in her bedroom before handing them over to Hoa for distribution. This production process, conducted under unsafe conditions, posed a risk of toxic substance leakage into the environment.

Police inspecting the store. Photo: Ho Chi Minh City Police

From 2024 until now, Hoa has sold over 3,000 boxes of arsenic-containing products to dental facilities nationwide, generating over 1,25 billion VND. Tang Hoang Vinh assisted Hoa with receiving and delivering the goods.

Investigators believe that dismantling this operation has prevented a timely infiltration of hazardous chemicals into the healthcare sector.

Quoc Thang