The Hong Kong Consumer Council (HCC) has released findings from an extensive safety review of common cooking oils, revealing that 60% of the tested products contain a chemical compound linked to potential long-term health risks if consumed excessively. While the contaminants were present, the HCC affirmed that none of the 30 affected samples exceeded the stricter safety limits established by the European Union (EU), assuring consumers that immediate health hazards are unlikely under normal usage.
The investigation, which spanned from late 2021 to early 2022, analyzed 50 diverse edible oil samples collected from major supermarkets and department stores across Hong Kong. The tested oils represented 13 distinct categories, including 14 varieties of extra virgin olive oil, six canola oils, six peanut oils, and several types of specialty oils like avocado, coconut, and rice bran oil. The primary focus of the safety assessment was the presence of 3-monochloropropane-1,2-diol esters, or 3-MCPDE.
Addressing 3-MCPDE: A High-Temperature Byproduct
The presence of 3-MCPDE is primarily a result of the high-temperature refining process used in many edible oils, specifically during the deodorizing stage which often occurs above 160 degrees Celsius. When ingested, 3-MCPDE hydrolyzes in the gastrointestinal tract, releasing the toxic substance 3-MCPD.
International regulatory bodies, including the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (JECFA) and the European Food Safety Authority (EFSA), have flagged 3-MCPD. Long-term, excessive intake in animal studies has been associated with adverse effects on kidney function, the central nervous system, and the male reproductive system.
While Hong Kong currently lacks specific maximum regulatory limits for 3-MCPD and its esters in edible oils, all 50 samples adhered to the existing EU standards for the sum of 3-MCPD and its esters.
To put the findings into perspective, the sample with the highest concentration (Carrington Farms’ “Coconut & Avocado Cooking Oil Blend,” at 1,900 micrograms per kilogram) would require a 60-kilogram adult to consume approximately 127 grams (JECFA recommendation) or 64 grams (EFSA recommendation) daily over a sustained period to exceed the recommended tolerable daily intake. The HCC concluded that consumption at typical dietary levels poses no discernible health risk.
Mislabeling Concerns Prompt Customs Referral
A significant finding concerned three samples, marketed as low-temperature or “cold-pressed” oils, which unexpectedly contained 3-MCPDE. These low-temperature methods typically avoid the high-heat processes that generate these contaminants.
The international standard for extra virgin olive oil and cold-pressed varieties is that they should be free from 3-MCPD and its esters. The three specific products identified were:
- Palermo Organic Extra Virgin Olive Oil First Cold Pressed
- Prolife Organic Wild Organic Cold Pressed Camellia Seed Oil Unrefined
- CanBest Organic Cold Pressed & Wild Camellia Oil Extra Light (Extra Virgin)
The HCC has referred these samples to the Customs and Excise Department for potential investigation into breaches of the Trade Descriptions Ordinance, as their contaminant content suggests a discrepancy between the product labeling and the actual processing methods used.
Choosing Contaminant-Free Cooking Oils
For Hong Kong consumers seeking oils completely free from 3-MCPDE contamination, the HCC identified several products that achieved full marks in overall safety testing. These oils are typically those processed at low temperatures, minimizing the formation of heat-induced contaminants.
Consumers are encouraged to consult the full report details published in the HCC’s Choice magazine (Issue 549), which lists the uncontaminated options. Among the categories with successful, high-ranking results were numerous extra virgin olive oils, select avocado and coconut oils, and a few sunflower, corn, and peanut varieties.
The findings underscore the importance of processing methodology in food safety. Consumers focused on minimizing heat-related contaminants should favour genuine cold-pressed or virgin oils, while being mindful that contaminants, though present, remain within acceptable international safety thresholds for most commonly used refined oils.