Q1 What is gutter oil ?
A1 There is no agreed definition of "gutter oil". Generally, it refers to discarded oil recovered from gutters and ditches.
Q2 What is Benzo[a]pyrene ?
A2 Benzo[a]pyrene (B[a]P) is a kind of polycyclic aromatic hydrocarbons (PAHs). PAHs are ubiquitous in the environment as contaminants, being present in air, soil, water and food.
Q3 Why is food contaminated with PAHs ?
A3 PAHs may be formed during incomplete combustion or burning of organic matters. Almost all food contains PAHs to a certain extent. The two major sources of B[a]P (a type of PAH) in food are deposition and uptake of B[a]P from polluted air on food crops and formation and deposition of B[a]P during heat processing using methods such as roasting, smoking, and grilling. Levels of B[a]P may vary depending on the processing conditions and are often higher in barbecued/smoked meat or fish. Furthermore for fats and oils, drying of cereals and plants used for production of crude vegetable oils using direct application of combustion gases can result in contamination of the products with B[a]P as combustion products may come into contact with the grain, oil seeds and thus increasing B[a]P level in the oil product. The level of B[a]P in oil would be much reduced after oil refining processes and the ultimate level of BaP would depend on the conditions under which refining takes place and quality control.
Q4 What is the major dietary source of PAHs ?
A4 Major dietary contributors of PAHs depend on the consumption pattern (amount and types of food consumed) and the levels of PAHs in foods. According to the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (JECFA), cereals and cereal products, vegetables fats and oils are major contributors to dietary exposure to PAHs.
Q5 Will the B[a]P level in oil increase after repeated deep-frying ?
A5 There are reports which suggest that the level of B[a]P in oil will increase after repeated use. Since many factors can lead to high levels of B[a]P in oil, one cannot judge if oil had undergone repeated use just by the level of B[a]P in it.
Q6 Does the existence of B[a]P in oil mean that the oil had undergone high heat treatment, which in turn means that the oil had been used for frying food previously? Does that equal to "gutter oil"?
A6 No. The presence of B[a]P in oil can be due to many different factors. Plant materials for oil production can be contaminated through deposits from air. The level of B[a]P in these materials can also increase through drying process using direct application of combustion gases. Furthermore, B[a]P level in oil may increase upon repeated use.
Q7 What amount of B[a]P consumed will be harmful to health ?
A7 B[a]P is toxic to genes and can cause cancer in human. B[a]P is classified as "carcinogenic to human" (i.e. Group 1 agent) by the International Agency for Research on Cancer (IARC) of the World Health Organization in 2009. Therefore, a safety reference value cannot be determined for B[a]P. To reduce the health risk associated with B[a]P, efforts should be made to minimise exposure to B[a]P as far as practicable.
Q8 Is there any international, regional or national regulation on B[a]P in edible oils ?
A8 The Codex Alimentarius Commission has not established standard of B[a]P in edible oils. The standards of B[a]P in edible oils in European Union and Mainland China were 2 μg /kg and 10 μg /kg respectively.
Q9 What is the action level for B[a]P in edible oils set by the Centre for Food Safety ( CFS ) ?
A9 In 2005, JECFA concluded that the estimated intakes of polycyclic aromatic hydrocarbons (PAHs) including B[a]P were of low concern for human health. In order to protect public health and address public concerns, the CFS has set an action level of 10μg/kg for B[a]P in edible oils, which is in line with the Mainland China standard. The action level was endorsed by the Expert Committee on Food Safety (Expert Committee).
Q10 Why does the CFS set 10 μg/kg as the action level for B[a]P in edible oils?
A10 The ultimate goal for setting an action level is to protect public health. The Expert Committee noted that based on local consumption data, even in the unlikely event that all edible oils consumed by a person is contaminated with 10μg/kg of B[a]P (the maximum limit established in Mainland China), the derived Margin of Exposure (MOE) will be greater than 10,000, indicating the estimated intake of B[a]P is of low concern for human health. In addition, since Mainland China is our main food supplier, setting the same action level as Mainland at 10 μg/kg can also avoid unnecessary trade barrier.
Q11 What are the follow-up actions taken by the CFS against edible oil samples found to exceed the action level ( i.e. 10μg/kg ) for B[a]P?
A11 If an edible oil sample is found to contain B[a]P at level equal or greater than 20μg/kg, the derived MOE will be lower than 10,000, indicating a public health concern. As such, CFS would take enforcement action in accordance with Section 541 of the Public Health and Municipal Services Ordinance (Cap. 132), and initiate a mandatory recall of the edible oil concerned. If an edible oil sample is found to contain B[a]P at level greater than 10μg/kg but lower than 20μg/kg, the derived MOE will be higher than 10,000, indicating that the public health concern is low. Nevertheless, under such scenario, CFS may still take enforcement action in accordance with Section 522 of the Public Health and Municipal Services Ordinance (Cap. 132). 1Section 54 of the Ordinance also stipulates that all food (including cooking oil) for sale must be fit for human consumption. 2Section 52 of the Public Health and Municipal Services Ordinance (Cap. 132) provides that if any person sells to the prejudice of a purchaser any food which is not of the nature, or not of the substance, or not of the quality, of the food demanded by the purchaser, he shall be guilty of an offence.
Q12 Does the action level for B[a]P in edible oils apply to the used ones?
A12 To protect public health, the action level for B[a]P apply to all edible oils no matter they are used or not. Since the level of B[a]P in edible oils may increase upon repeated use, the trade should ensure the quality of all oils used for further food processing can achieve this action level.
Q13 Can the action level of B[a]P in edible oils be applied to fat?
A13 Since oils can be converted to fat by various chemical methods (e.g. hydrogenation), the action level of B[a]P on edible oils can also be applied to fat.
Q14 It is noted that the European Commission has set a more stringent standard for B[a]P in oils and fats. Can the action level set by the CFS adequately protect public health?
A14 The CFS has conducted risk assessment using the MOE approach to determine whether there is any potential health risk in response to the adoption of the action level for B[a]P in edible oils at 10 μg/kg. It is noted that even in the unlikely event that all edible oils consumed by a person is contaminated with 10μg/kg of B[a]P, the derived MOE will be greater than 10,000, indicating the estimated intake of B[a]P is of low concern for human health. Since contaminant s including B[a]P in food should be as low as reasonably achievable through best practice such as Good Manufacturing Practice. The CFS will continue to advise the trade to take necessary measures in order to reduce the level of B[a]P in food including oils.
Q15 PAHs are a group of substances. Why does the CFS set action level for B[a]P only?
A15 Currently, B[a]P is the only PAH classified as "carcinogenic to human" (i.e. Group 1 agent) by the International Agency for Research on Cancer (IARC) of the World Health Organization. The Codex Alimentarius Commission has not established any standard for PAHs including B[a]P in food. It is noted that the European Commission, Korea and m ainland China have established maximum level for B[a]P in oils while only the European Commission has set maximum level for other PAHs in food. The CFS will continue to monitor the international development.
Q16 Is there any advice on reducing exposure to B[a]P ?
A16 Public should maintain a balanced and varied diet, which includes a wide variety of fruits and vegetables; Do not use reused cooking oil; avoid overindulgence in barbecued meat, particularly charcoal grilled meat and smoked meat/fish; and remove charred parts of food. Public may reduce consumption of fats and oils to reduce B[a]P exposure.