Auramine O is the commercial name for diarylmethane – a compound used exclusively in industrial applications for dyeing textiles, paper, and wood, as well as in paint formulations; in the medical field, it is used for staining acid-fast bacteria and Auramine O is strictly prohibited in food applications. This article provides insights into Auramine O, its associated health risks, and foods that may be at risk of contamination.

1. What is Auramine O and Where is it Used?

Auramine O is the commercial name for diarylmethane – a yellow, needle-shaped crystalline powder that is highly soluble in water and alcohol. Its chemical formula is C17H21N31.

This compound is strictly limited to industrial applications such as dyeing textiles, paper, wood, and paints. In medical laboratories, it is occasionally used for staining acid-fast bacteria…

Auramine O is explicitly banned from food use. The Ministry of Agriculture and Rural Development of Vietnam has issued Circular No. 42, adding Auramine and its derivatives (Basic Yellow 2) to the list of chemicals and antibiotics prohibited from importation, production, trade, and use in animal feed for livestock and poultry in Vietnam.

Other yellow colorants prohibited for use in food include:

- Vat Yellow 1 (also known as flavanthrone, flavanthrene and sandothrene)
- Vat Yellow 2 (also known as Indanthrene)
- Vat Yellow 3 (also known as Mikethrene)
- Vat Yellow 4 (also known as Dibenzochrysenedione and Dibenzpyrenequinone)l
- Auramine (also known as yellow pyoctanine and glauramine) and its derivatives.

What is Auramine O and Where is it Used

2. What Foods are at Risk of Auramine O Contamination?

According to food safety experts, in case of durian, Auramine O is often used to enhance its appearance, making it look more vibrant and appealing.

In case of bamboo shoots, naturally, fresh or dried bamboo shoots have a pale yellow color. However, those soaked in Auramine O will have an intense yellow hue. Additionally, chemically treated bamboo shoots tend to be more brittle and break easily, while naturally salted ones remain more flexible.

In case of poultry, when mixed into animal feed, Auramine O can give chicken skin and egg yolks a more intense yellow coloration…

Therefore, consumers need to avoid purchasing unusually vibrant-colored food items, such as excessively yellow chicken skin, egg yolks, or bamboo shoots with unnaturally deep hues…

Producers and businesses must strictly refrain from using Auramine O in the production and processing of agricultural products and food to safeguard the health and lives of both producers and consumers.

3. What are the Toxic Effects of Auramine O?

3.1. Acute Toxicity:

- Respiratory Tract: Causes severe irritation, leading to coughing, bronchitis, and pneumonia.
- Digestive System: Induces abdominal pain, nausea, throat irritation, and diarrhea.
- Skin Contact: Triggers itching, peeling, and ulceration.

3.2. Chronic Toxicity:

- Carcinogenic Potential: Animal studies indicate that Auramine O can induce cancer in rodents. The International Agency for Research on Cancer (IARC) has classified Auramine O as a Group 2B carcinogen, meaning it is potentially carcinogenic to humans.
- DNA Damage: Auramine O can disrupt nucleic acids in DNA, particularly affecting liver, kidney, and bone marrow cells.
- Impact on Children: Prolonged exposure in children may cause hyperactivity, inattention, and cognitive impairments.
- Inflammation and Edema: Direct exposure can lead to localized inflammation, particularly in mucous membranes. Skin, mouth, nose, and eyes are the most commonly affected areas

4. Where Can Food Be Tested for Auramine O Contamination?

Concerns over Vietnamese durian exports to China suspected of Auramine O contamination have led to stricter testing protocols. As of January 26, 2025, nine certified laboratories in Vietnam have been officially recognized by China for Auramine O testing in agricultural products. These accredited testing centers are located in Hanoi, Hai Phong, Da Nang, Ho Chi Minh City, Can Tho, and Ca Mau:

- - Quality, Processing, and Market Development Center – Region 1 – Address: 51 Le Lai, Ngo Quyen, Hai Phong
  - Quality, Processing, and Market Development Center – Region 2 – Address: 167-175 Chuong Duong, My An Ward, Ngu Hanh Son District, Da Nang
  - Quality, Processing, and Market Development Center – Region 4 – Laboratory: 271 To Ngoc Van, Linh Dong Ward, Thu Duc City, Ho Chi Minh City. Headquarters: 91 Hai Thuong Lan Ong, Ward 10, District 5, Ho Chi Minh City
  - Quality, Processing, and Market Development Center – Region 5 – Address: 57 Phan Ngoc Hien, Ward 6, Ca Mau
  - Quality, Processing, and Market Development Center – Region 6 – Address: 386C Cach Mang Thang Tam, Bui Huu Nghia Ward, Binh Thuy District, Can Tho
  - Hoan Vu Science and Technology JSC – Laboratory: 59-65 To Hieu, Hiep Tan Ward, Tan Phu District, Ho Chi Minh City
  - NHONHO Technology Co., Ltd. – Address: K2-17 Vo Nguyen Giap, Phu Thu Ward, Cai Rang District, Can Tho
  - National Institute for Food Control – Address: 65 Pham Than Duat, Mai Dich Ward, Cau Giay District, Hanoi
  - Northern Pesticide Testing and Inspection Center – Address: 7A Le Van Hien, Duc Thang Ward, Bac Tu Liem District, Hanoi.