Melamine tableware, commonly known as ‘Imitation porcelain tableware’, is made of A5 or A8 grade melamine resin as raw material as lookalike as porcelain tableware. This is durable, virtually unbreakable, corrosion-resistant, lightweight, heat-holding, odourless, toxic-free and highly plasticity. Melamine tableware and kitchenware are a popular choice because these are in affordable prices and a wide array of colours and shapes, such as chopsticks, dishes, bowls, cups and ladles.

There are many materials for making imitation porcelain tableware. Among them, melamine and formaldehyde are the main materials of plastic polymer. In the case of high temperature or other specific conditions, these two chemicals are likely to release from the tableware then may transfer into food. Long-term consumption of this contaminated food can pose a potential health risk hence the safety of melamine tableware becomes a matter of public concern.

According to the scientific assessments on the safety of tableware made from melamine-formaldehyde resin conducted by the European Union and the United States, it has revealed that temperature and acids can accelerate the migration of melamine and formaldehyde from tableware. When such tableware is heated directly over 70ºC by a fire or microwave oven, or is immersed in 3% acetic acid or other solutions of the same acidity, the resin breaks down and releases melamine and formaldehyde, in some of which are transferred to foodstuffs and some formaldehyde can be discharged into the atmosphere. For this reason, the melamine-formaldehyde resin is not used in making kitchen utensils (e.g. kettle and cookware) so as to prevent health risks caused by the harmful substances entering the body through food and respiration.

Although food contact materials may contain of migratable substances, the extent of health impact must be judged by reasonable scientific evidences, such as the stability of chemicals, quantity released and identified hazards. In the case of melamine tableware, the plastic resin is substantially stable and does not release any chemicals at room temperature. However, when the temperature rises over time, the plastic begins to break down at boiling. The released formaldehyde and melamine are transferred to the contacted food. Unless the tableware is obviously deformed or melted, our naked eyes and nose cannot detect those chemical. Therefore, in many countries, food contact materials are subject to establish the set of quality standards for tableware and kitchenware based on risk assessment findings in order to monitor and control the release quantity of potentially hazardous materials.

China is one of the main manufacturers and exporters of melamine tableware in the world. It has established a comprehensive national food safety standard to regulate the “General Safety Requirements on Food Contact Materials and Articles (GB4806.1-2016)”, ensuring that the food contact articles comply with food safety requirements, are traceable and provide clear and authentic product information. In terms of protecting consumers’ right to know, these products must be marked with precautions for use, the national quality statement, usage specification such as intended purpose, condition, temperature, etc. As the majority of the melamine tableware in Macao comes from China, the public shall basically know the correct use method from the product label or user manual to reduce the risk of food safety.

Besides the general principles, the production technology and quality of tableware made from the melamine-formaldehyde resin must comply with the standards requirement in the “Plastic Resin used in Food-Contact (GB4806.6-2016)”. Particularly, this regulation has established the safety setpoints for the maximum permitted amounts of chemicals released from food-contact materials. For examples, the Specific Migration Limit (SML) of formaldehyde is 15 mg/kg, and melamine is 2.5 mg/kg in general melamine-formaldehyde resin products. As to better protect the health of infants and young children, the SML of melamine is 1 mg/kg that is used to produce a plastic or product in contact with their foods. If the quantity of migrating substances exceeds the stipulated limits or the quality of the materials fails to meet the prescribed grading criteria, the suspected products must be taken off shelves and recalled so as to eliminate food safety risks.

Actually, in the light of the results of hazard identification and analysis for melamine and formaldehyde, both chemical substances may have adverse effects on human health under certain conditions. For instance, only exposure to high doses of melamine can cause bladder and kidney stones, but food does not contain this substance. It is proven that only long-term exposure to formaldehyde in working environments can lead to the development of nasopharyngeal cancer in human. Despite the availability of state-of-the-art technology, there is a lack of valid data on biological metabolism to interpret whether the formaldehyde-containing food could have adverse effects on health. Moreover, many studies on melamine tableware have pointed out that the migration of melamine and formaldehyde is low under the correct using conditions, and most of the samples in the test complied with the National Specific Migration Limits of the European Union. Since the quantity of released substances is insignificant and has no obvious adverse effects on health, there is no need for the public to worry of harmful substances from the melamine-ware entering into our body.

Advice for the public:

1. Pay attention to the product specification of melamine-ware to ensure the safety of its quality, and use it within the scope of applicable food types and temperature range;
2. Do not use melamine-ware with abnormal odour, cracks or scratches on the surface;
3. Do not use melamine-ware for heating or cooking food, such as using melamine chopsticks to cook instant noodles or fry food;
4. Never put melamine-ware into a microwave oven or oven for heating;
5. Keep melamine-ware away from open flame or direct sunlight to avoid the deformation of plastic;
6. Do not use melamine-ware to hold acidic foodstuffs, such as orange juice and pickled vegetables;
7. Never use melamine-ware to hold hot oil;
8. When holding the high-temperature food, allow the food to cool down at 70ºC or below before placing it into the melamine-ware;
9. Do not use abrasive or strong detergents for cleaning melamine-ware so as to avoid damaging its surface.

Advice for the industry:

1. Buy melamine-ware from reliable suppliers to ensure that its quality complies with the national safety standards of food-contact materials and articles;
2. Use melamine tableware and kitchen utensils within the scope of application as same as written in the user manual in order to reduce food safety risk caused by deterioration of the materials.

033/DIR/DSA/2019