Report No. 11

Chemical Hazard Evaluation

Acrylamide in Food

December 2003
Food and Environmental Hygiene Department
The Government of the Hong Kong Special Administrative Region

This is a publication of the Food and Public Health Branch of the Food and Environmental Hygiene Department of the Government of the Hong Kong Special Administrative Region. Under no circumstances should the research data contained herein be reproduced, reviewed, or abstracted in part or in whole, or in conjunction with other publications or research work unless a written permission is obtained from the Department. Acknowledgement is required if other parts of this publication are used.


Risk Assessment Section

Food and Environmental Hygiene Department

43/F, Queensway Government Offices,

66 Queensway, Hong Kong.


Table of Contents





Results and Discussion

Conclusions and Recommendations


Annex I  :  Food groups for acrylamide analysis

Annex II  :  Levels of acrylamide in various food groups


Acrylamide is a toxic and potentially carcinogenic chemical.  Following the announcement by the National Food Administration in Sweden that acrylamide was found in many types of food, especially starch-containing food with high-temperature treatment, the Food and Environmental Hygiene Department took some 450 food samples available in the local market for acrylamide analysis to assess the situation in Hong Kong.  Local staple food of steamed rice, soup noodles and congee were not found to contain appreciable amount of acrylamide.  The acrylamide levels in the more commonly consumed food items in the food groups rice and rice products, noodles, bakery and batter-based products which were subject to frying, baking and grilling were generally less than 60μg/kg. Higher levels were found in the food groups biscuit related products and crisps. The highest levels were detected in potato crisps (1500 to 1700μg/kg).  The present data on acrylamide are not sufficient to warrant changes in basic dietary advice on healthy eating, i.e., have a balanced and varied diet, eat more fruits and vegetables, and should moderate consumption of fried and fatty foods.

Risk Assessment Studies -

Acrylamide in Food

An investigation of acrylamide in Asian Food available in Hong Kong



  In April 2002, the Swedish National Food Administration (NFA) and researchers from Stockholm University released a study finding that acrylamide was detected in a variety of common foods cooked at high temperature such as chips (French fries), potato crisps, breakfast cereals and cookies etc.  Subsequent studies from Norway, Switzerland, United Kingdom and United States had also found elevated levels of acrylamide in such foods.  The discovery of acrylamide in food is a public health concern because acrylamide is a potential carcinogen and genotoxicant. 

2.   In view of the findings, an expert consultation convened jointly by the Food and Agriculture Organisation of the United Nation (FAO) and the World Health Organisation (WHO) in June 2002.  The Consultation recognized that the issue is a major concern and acknowledged the potential link between acrylamide and carbohydrate-rich foods cooked at high temperature.  The Consultation considered that the existing data is insufficient to allow a quantitative estimate of cancer risks from dietary acrylamide.  Besides, data in food consumed in regions other than Europe and North America is lacking and called for more research in this area.

3.   In view of the public health risk of this issue, the Food and Environment Hygiene Department (FEHD) thus considered that there is a need to conduct a study to determine the acrylamide levels in foods of our local diets especially Asian food (e.g. fried rice, fried noodles, fried dim sum (點心) and yau-hei (i.e. deep-fried dough) (油器) etc.). 

Use of acrylamide 

4. Acrylamide is an odourless, white, crystalline organic solid with melting point of 84-86°C. [1]   It readily undergoes polymerization to form polyacrylamide, which is a highly cross-linked gel polymer with many uses in industry.  Polyacrylamides are used as a coagulant aid in the treatment of drinking water and waste water.  It is also used in paper, textile and plastic industries, and synthesis of dyes, as a grouting agent in the construction of dam foundation, tunnels and sewers. 

Source of exposure

5.   Prior to NFA's announcement, the major health concerns associated with acrylamide were the exposure through drinking water and in occupational exposure, while acrylamide from diet is not known as an exposure.  Polyacrylamide is used as a coagulant aid in drinking water treatment and trace amounts of non-polymerized acrylamides may present in drinking water. [2]   The WHO Guideline for Drinking Water Quality has established a guideline value of 0.5μg/litre for acrylamide in drinking water.  Residual acrylamide from packaging material contributes a negligible exposure. [3]  

Health implications of acrylamide

6.   Ingested acrylamide is readily absorbed from the gastrointestinal tract and mainly excreted via urine, with small amounts eliminated via faeces and exhalation.

7.   Acute toxicity caused by acrylamide is rarely encountered in humans.  Neurotoxicity is the only recognized adverse effect of oral acrylamide exposure for humans, affecting sensory and/or motor functions.  The WHO Consultation in June 2002 supported the "No Observed Adverse Effect Level" (NOAEL) for acrylamide neurotoxicity of 0.5 mg per kg body weight per day previously established.  The LD50 values ranged from 107 - 203 mg/kg body weight was shown in rats. [4]  

8.   Acrylamide is genotoxic in vivo, therefore acrylamide has the potential to induce heritable damage at gene and chromosome level. 

9.     Acrylamide is carcinogenic in experimental animals producing increased incidences of a number of benign and malignant tumours in various organs, including thyroid, adrenal, brain, lung, skin, etc.  For humans, the relative potencies of cancer causation due to acrylamide in food are not known. [5]  

10.   In 1994, International Agency for Research on Cancer (IARC) evaluated acrylamide and considered that there was sufficient evidence of carcinogencity in experimental animals but inadequate evidence of carcinogenicity in humans and classified it as Group 2A (probably carcinogenic to humans).  This classification was endorsed by the WHO Consultation in 2002. 

Formation of acrylamide in food

11.     At present, research findings revealed that raw food and foodstuffs that are prepared by boiling do not contain appreciable levels of acrylamide. [6] Acrylamide is formed when food, particularly those rich in carbohydrate are cooked at above 120°C. [5] Current evidence suggests that acrylamide may be formed in food in chemical reaction which requires the presence of the amino acid, asparagines and reducing sugars under certain conditions.

12.     The mechanism involved in acrylamide formation during the food processing is still uncertain.  Researches are underway in many parts of the world to find out the exact mechanism of formation of acrylamide in food. 


13. This study aims to determine the levels of acrylamide in food available in local market.



14.   For the purpose of this study, a wide range of carbohydrate-rich food was taken for acrylamide analysis.  These food were subjected to high-temperature cooking, principally >120°C such as grilling, roasting, baking, barbecuing, frying and deep-frying.  Asian style foods such as Chinese, Japanese, Indian, Indonesian, Malaysian, Thai, Vietnamese style, as well as some Western foods were included.  They might be in a form of ready-to-eat, mixed dishes and pre-packaged.  Food samples were collected from various restaurants, supermarkets, bakeries and other retail outlets. 

15.     The popularity and availability of the food / products formed the major selection criteria.  Mixed dishes were mainly in a form of "composite sample".  Samples collected randomly from three to four sources were mixed and homogenized, otherwise, food samples were analysed individually.  The food groups are shown in Annex I.

Laboratory analysis

16.   Laboratory analyses were conducted by the Food Research Laboratory (FRL) of the FEHD.

17.   The edible portion of the food sample was homogenized and an appropriate test portion (1-4 g) was taken. The acrylamide in the test portion was extracted by water and then, cleaned up by solid phase extraction, and subsequently determined by Liquid Chromatograph-Tandem Mass Spectrometry (LC-MS/MS) technique. Acrylamide-1,2,3-C13 was used as an internal reference (surrogate) for the analysis.  The test method was validated by single-laboratory validation.  The limit of detection and the limit of quantification were 3µg/kg and 10µg/kg respectively.   


18. Some 450 food samples were collected and sent to the FRL for acrylamide analysis.  A total of 156 analyses had been conducted.  The results are listed in Annex II.

19. On the whole, high-temperature treated carbohydrate-rich foods contained acrylamide. The levels of acrylamide in the more commonly consumed Asian style food items in the food groups rice and rice product dishes, noodles, bakery products and batter-based products were low and generally less than 60μg/kg, except for deep-fried sizzling rice (guo-ba) and Japanese fried noodle (teppan-yaki soba) with levels up to 67μg/kg and 84μg/kg respectively. Similar levels were found in most of the food items in the Asian delicacies food group, which included Chinese dim sum and other deep-fried products. Higher levels were detected in deep-fried taro meat dumpling at 190μg/kg and Chinese fried fritters with range 95 to 170μg/kg.  On the other hand, staple food of steamed rice, soup noodles and congee were not found to contain appreciable amount of acrylamide.

20. Higher acrylamide levels up to above 1000μg/kg were found in the two food groups biscuit related products and crisps. The ranges of acrylamide content in some of the subgroups were quite wide, probably due to the variation in food processing conditions. The highest levels were found in potato crisps with range 1500 to 1700μg/kg. Apart from banana crisp (770μg/kg) and taro crisp (320μg/kg), the acrylamide levels in other fruit/vegetable-based crisps were quite low, ranging from less than 3 to 86μg/kg. The acrylamide levels in rye flour-based crisps (440μg/kg) were considerably lower than those in the potato ones, followed by corn-based (65 to 230μg/kg) and wheat flour-based crisps (61 to 200μg/kg), and then rice flour-based crisps (17 to 42μg/kg). The products in these two food groups are crispy with low moisture content. Moreover, the crisps are in thin slice forms with large specific surface area. As the amount of acrylamide was measured per unit weight of food and the acrylamide would be formed mainly on the food surface during heating, these two factors of low moisture content and large specific surface area would contribute to the generally higher acrylamide level.

21. In general, the acrylamide level in processed meat and seafood products was very low, less than 3μg/kg. The exception was grilled fish slice in Indonesian style with acrylamide at a level of 93μg/kg. This might require further investigation as to the ingredients and processing conditions of the food product.

22. The results for potato crisps, corn crisps, potato chips and batter-based products were within the ranges reported by some European countries and the USA in the FAO/WHO consultation meeting in June 2002. [5] For the case of Asian foods, the results for spring roll, rice cracker and battered fried vegetables (tempura) were comparable to those reported elsewhere. [7]

Estimation of dietary exposure

23. Dietary exposure to acrylamide in the local population was estimated by combining the results of the present study and data from the Hong Kong Adult Dietary Survey 1995 [8] and the Food Consumption Survey in Secondary School Student 2000 [9] .  The result revealed that dietary exposure to acrylamide of an average citizen in Hong Kong is about 0.3µg/kg body weight /day while that for an average secondary school student is about 0.4µg/kg body weight /day.  Both of them fell within the lower end of the range of dietary intake of acrylamide in the western diet (i.e. 0.3 to 0.8µg/kg body weight /day) as estimated by the WHO at the expert consultation meeting in June 2002


24. Acrylamide was found present in heated carbohydrate-rich foods such as those prepared by grilling, roasting, baking, frying and deep-frying. The levels varied according to the food material and processing conditions. The study on Asian indigenous foods available in Hong Kong showed that the levels of acrylamide in the commonly consumed foods such as rice, noodles, bakery and batter-based products were in general low, while higher levels were present in snack foods such as biscuits, chips and crisps.  Local staple foods of steamed rice, soup noodles and congee were not found to contain appreciable amount of acrylamide.  Dietary exposure to acrylamide in the local population is on the low side when compared with dietary intake of acrylamide in the western diet.

25. At present, the data on acrylamide are not sufficient to warrant changes in basic dietary advice on healthy eating, i.e., have a balanced and varied diet, eat more fruits and vegetables, and should moderate consumption of fried and fatty foods.

26. To minimize the risk of acrylamide in food, food should not be cooked excessively, i.e. for too long or at too high temperature. However, all food particularly meat and meat products should be cooked thoroughly to destroy foodborne pathogens.


[1] The Commission of European Union. The International Chemical Safety Cards: Acrylamide - ICSC: 0091. 2000 Apr. [cited 2002 Nov 20]. Available from : URL:

[2] WHO.  Guidelines for drinking-water quality. 2nd ed. Geneva:WHO; 1993.

[3] WHO.  Acrylamide. Health and Safety Guide No. 45 Geneva: WHO; 1991. [cited 2002 Nov 20]. Available from: URL:

[4] European Commission. Risk Assessment of Acrylamide. 2000 Oct. [cited 2002 Nov 20]. Available from: URL:

[5] WHO. Health Implications of Acrylamide in Food: Report of a joint FAO/WHO consultation, WHO Headquarters, Geneva, Switerland, 25-27 June 2002.  Geneva: WHO; 2002.

[6] European Commission. Opinion of the Scientific Committee on Food on new findings regarding the presence of acrylamide in food.  Belgium: European Commission; 2002 [cited 2002 Nov 20]. Available from: URL:

[7] Ono H, Chuda Y, Ohnishi-kameyama M, Yada H, Ishizaka M, Kobayashi H, et al.  Analysis of acrylamide by LC-MS/MS and GC-MS in processed Japanese foods.  Food Additives and Contaminants 2003; 20:215 - 20.

[8] Leung S, Ho S, Woo J, Lam TH, Janus ED.  Hong Kong Adult Dietary Sruvey 1995.  Hong Kong: Chinese University of Hong Kong and University of Hong Kong; 1995.

[9] FEHD.  Food Consumption Survey 2000.  Hong Kong: FEHD; 2001.

Annex I : Food Groups for acrylamide analysis

Food Group Characteristics Sub- group
Rice Refers to pre-cooked rice (except steamed/boiled rice) that undergoes stir-frying, pan-frying, deep-frying, grilling, baking.

Fried rice/baked rice/deep-fried rice/ grilled
rice/ steamed rice/ boiled rice


Refers to pre-boiled noodles/pasta (except boiled soup noodles) that undergoes stir-frying, pan-frying, deep-frying.

Wheat based

Fried noodles/ Instant noodles/ cup noodles/
fried spaghetti//baked spaghetti/ boiled noodles

Rice based Fried rice noodles/ Fried flattened noodles

Oriental delicacies

Refers to some Chinese dumplings, wraps, roll stuffed with meat, that undergoes pan-frying, deep-frying.


Deep fried dumpling/ fried dumpling/
deep-fried roll


Deep fried dumpling


Deep-fried rice roll/fried turnip cake

Refers to wheat-flour dough that undergoes deep-frying.  No stuffing is required. Yau-hei (油器) Yau-hei (Deep-fried dough without stuffing)
Bread Refers to a fermented/leavened dough that undergoes baking, toasting, pan-frying, deep-frying, steaming.

Soft bread/ toast (medium) / fried bun/
deep-fried bun/ steamed bun

Confectionery Refers to dough (but not bread) that undergoes baking.





Refers to shaped dough that undergoes baking.

Rice flour based Rice cracker
Wheat flour based

Cracker (e.g soda, cream cracker)/
Biscuit (e.g wafer, cookie, digestive, shortbread)

Rye flour based Crispbread
Crisps Refers to either sliced whole potato, shaped flour-based cereal /fruit/ vegetable that undergoes baking, deep-frying, roasting, freeze drying. Cereal based

Potato crisps/ corn crisps/ wheat crisps/
rice crisps/ rye crisps/ mix of potato/corn/
wheat crisps/ starch crisps

Fruit crisps (e.g jackfruit crisps, apple crisps,
banana crisps)

Potatoes Refers to potato undergoes either deep-frying or baking. Deep-fried potato/roasted potato

Vegetables (other than potato) and fruits

Refers to starchy vegetable/fruit that undergoes roasting, battered deep-frying, deep-frying.


Roasted yam/ roasted chestnut/ tempura
(battered-fried vegetables) Taro crisps/
green pea

Fruit Jackfruit crisps/ banana crisps/ apple crisps
Refers to fresh starchy vegetable/ fruit. Vegetable / Fruit Fresh taro/ banana/ jackfruit

Breakfast Cereals Products

Refers to pre-packed processed cereal products that often serve in breakfast.

Corn based Cornflakes
Oat based Instant oat meals
Mix of wheat/ rice Instant cereal drink

Meat, fish and seafood products

Refers to meat/processed meat products that undergo deep-frying, grilling. Meat

Crumbled-fried pork chop/ barbecued
pork jerky/ deep fried sausage

Refers to processed fish and seafood products that undergo deep-frying, grilling. Processed fish and Seafood

Deep-fried fish ball/ grilled fish slice

Deep - fried shrimp/ Battered-fried
octopus/deep-fried shrimp cake

Batter-based Products

Refers to batter that undergoes pan-frying. 

Refers to batter that undergoes grilling, toasting.

Pancake/ grilled egg roll/ waffle/ egg custards


Black Coffee, ready to drink
Instant Chinese Soup

Annex II : Levels of acrylamide in various food groups

Food Group Total no. of analysis Sub-group No. of analysis Range of conc. (µg/kg) Media conc*. (µg/kg) Mean conc*. (µg/kg)
Rice 11 Fried rice 4 <3- 15 <3 9
Baked rice 2 <3
Deep-fried rice 1 67
Grilled rice 1 <3
Steamed rice 2 <3
Boiled rice 1 <3
Noodles 13 Wheat based Fried noodles 5 <3-84 <3 21
Instant noodles 1 <3
Cup noodles 1 <3
Boiled noodles 1 <3
Fried spaghetti 1 56
Baked spaghetti 1 <3
Rice based Fried noodles 1 <3
Fried flattened noodles 2 38-43
Bread 12 Soft Bread 2 <3-18 <10 13
Toast (medium) 3 <10-38
Fried bun 3 <10-33
Deep-fried 4 <3-18
Oriental delicacies 11 Wheat-based dim sum Deep-fried dumpling 1 <3 27 44
Fried dumpling 1 <3
Deep-fried roll 2 27-59
Taro-based dim sum Deep-fried dumpling 1 190
Rice-based dim sum Fried rice roll 1 <3
Fried turnip cake 1 <3
Yau-hei Deep-fried Dough 4 <3-170
Confectionery 7 Cake 4 <3-14 <10 14
Tart 1 <10
Pastry 2 14-57
Biscuits 26 Rice flour based Rice cracker 3 15-23 185 268
Wheat flour based Crackers 10 33-660
Wafer 2 110-290
Biscuit stick 4 47-1100
Cookie 2 71-240
Digestive 2 110-340
Shortbread 1 12
Rye flour based Crispbread 2 270-740
Crisps 32 Cereal based Potato crisps 3 1300-1700 110 251
Corn crisps 6 65-230
Wheat crisps 10 61-200
Rice crisps 2 17-42
Rye crisps 1 440
Mix of potato/ corn/ wheat 3 260-460
Starch 7 <3-26
Potatoes 4 Deep-fried 3 100-340 220 220
Roasted 1 240
Vegetable (other than potato) and fruit 12 Vegetable Vegetable tempura 1 32 25 110
Roasted chestnut 1 28
Roasted sweet potato 1 66
Fruit Battered fried banana 1 21
Fruit based Fruit crisps 3 <3-770
Vegetable based Vegetable crisps 2 86-320
Fresh vegetable/ fruit 3 <3
Meat, fish and seafood products 11 Meat Crumbed-fried pork chop 1 <3 <3 10
Barbecued pork jerky 1 <3
Deep-fried pork chop 1 <3
Grilled sausage 1 <3
Fish and seafood Deep-fried shrimp 1 <3
Battered-fried octopus 1 <3
Deep-fried fish ball 3 <3
Deep-fried shrimp cake 1 <3
Grilled fish slice 1 93
Breakfast cereals products 3 Corn based Cornflakes 1 100 <10 36
Oat based Instant Oat meals 1 <3
Mix of wheat/ rice Instant Cereal Drink 1 <10
Batter- based Products 5 Grilled egg roll 1 <3 <10 10
Grilled waffle 1 <3
Grilled egg custard 1 <3
Pan-cake 2 16-26
Pizza 3 11-51 42 35
Black Coffee, ready to drink 3 - - <3-13 <3 5
Instant Chinese Soup 3 - - <3 <3 1.5
Total 156     156      

* 1/2 LOD and 1/2(LOD+ LOQ) were assigned to non-detects and results below quantification respectively for the calculation of median and mean levels

Composite sample,

<Single sample .