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Food Safety Focus (60th Issue, July 2011) – Incident in Focus

Plasticisers and Food Safety

Reported by Ms. Melva CHEN, Scientific Officer,
Risk Assessment Section,Centre for Food Safety

In the past issue we talked about our responses to plasticiser-tainted food incident originated in Taiwan. Concerns remain as potential problems associated with plasticisers continue to unfold. This article continues to discuss risks associated with plasticisers and the related food safety issues.

Plasticisers are Used Primarily in Polyvinyl Chloride (PVC) Products

Since the emergence of the plasticiser-tainted food incident, many people worried about the migration of plasticisers from plastic materials into food and the associated health risk. In fact, plasticisers are substances mainly used in hard plastics to improve their flexibility and durability. PVC is the most common hard plastic material that uses plasticisers. Therefore, food containers, commercial cling films, gaskets used to seal the metal lids of glass jars, conveyer belts, gloves, made of PVC as well as adhesives and printing ink on food packaging contain plasticisers. On the other hand, soft plastics such as polyethylene terephthalate (PET) and polyethylene (PE) are inherently flexible and therefore do not require the use of plasticisers (see Table 1).

The industry has been using many types of plasticisers including phthalates, adipates, epoxy esters and citrates. Of these, phthalates such as DEHP and DBP have received the most regulatory and scientific attention due to their toxicity on reproduction and development in experimental animals.

Table 1. Types and Applications of Plastic Materials

* Note: The resin identification code system is a set of symbols placed on plastics to identify the polymer type. The primary purpose of the codes is to allow efficient separation of different polymer types for recycling.

Source of information: Environment Protection Department, Plastics New Zealand, British Plastics Federation and International Life Sciences Institute

What Affects Migration of Plasticisers into Food

When PVC food contact materials are properly manufactured and used, the plasticisers contained in the materials are not expected to migrate excessively into foodstuffs. However, as plasticisers are oil-soluble, plastics containing plasticisers, especially phthalates (i.e. in the case of PVC products) should not be used in food contact materials for holding fatty foods. Local and overseas data showed that some fatty foods such as edible oils, oil-based sauces and cheese were detected with low levels of phthalates, possibly related to environmental contamination or inappropriate use of food contact materials. Migration of plasticisers also increases with temperature and contact time. Plastics containing phthalates plasticisers should not be used in food contact materials intended for foods for infants and children under three years old as they are more susceptible to the toxicity of phthalates. On the whole, manufacturers of food contact materials have the responsibility to conduct prior use tests on their products to ensure that they are safe under the intended conditions of use.

Key Points to Note:

  1. Plasticisers are used primarily in PVC products.
  2. Migration of plasticisers from PVC materials increases when in contact with fatty or hot foods.
  3. Exposure to low level of plasticisers is unavoidable due to their widespread presence as environmental contaminants but can be reduced with proper use of food contact materials.

Actions Taken by the CFS

The CFS has been actively managing the plasticiser-tainted food incident originated in Taiwan , especially in two main aspects:

  1. Surveillance and Testing: The CFS has enhanced surveillance and testing of various categories of food products for phthalates including DEHP, DINP and DBP. We have worked closely with trade on minimising the impact to the public. Press release and food alerts will be issued when public health is of concern.
  2. Risk Communication: The public are updated on the test results and the latest development at the CFS designated webpage Plasticisers in Food which also provides explanations to questions that are of public concern. The CFS webpage provides safety information related to food contact materials, including risk assessment studies of disposable plastic containers for take-away meals , instant cup noodle containers and melamine-ware available for use on local food premises and risk-in-briefs on the safety of bisphenol A and reusing of PET bottles .

Reducing Exposure to Plasticisers from Food

Plasticisers are widely used industrial chemicals. Due to their widespread presence as environmental contaminants, exposure to low levels of plasticisers through food, water or skin contact with plastics is unavoidable. Our bodies can effectively metabolise and excrete plasticisers such as phthalates. Exposure to low levels of phthalates is unlikely to pose a health risk. We can take the following measures to reduce our exposures to phthalates.

Advice to Consumers

  1. Follow manufacturer's instructions especially on the temperature specifications and microwave and dishwasher instructions when using plastic food containers.
  2. Do not use PVC or unidentifi ed plastic containers to hold fatty foods or hot foods. Use glass, ceramic or stainless steel containers instead.
  3. When using or reusing glass jar, make sure the fatty foods do not come into contact with the gasket of the lid.

Advice to the Trade

  1. Manufacturers of food contact materials should provide product information and instructions on use.
  2. Food trade should observe good manufacturing and food safety practice. Ensure food products comply with local regulations.
  3. Avoid using phthalate-containing food contact materials, especially for fatty foods and food intended for infants and young children.