The Food Safety of Instant Cup Noodle Containers

Risk Assessment Studies
Report No. 36



Chemical Hazard Evaluation





The Food Safety of Instant Cup Noodle
Containers













May 2009

Centre for Food Safety
Food and Environmental Hygiene Department
The Government of the Hong Kong Special Administrative Region

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This is a publication of the Centre for Food
Safety 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 Centre for Food
Safety. Acknowledgement is required if other
parts of this publication are used.

Correspondence:
Risk Assessment Section
Centre for Food Safety,
Food and Environmental Hygiene Department,
43/F, Queensway Government Offices,
66 Queensway, Hong Kong.
Email: enquiries@fehd.gov.hk
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Table of Contents

Page


Executive Summary
2


Objectives 5


Background 5


Scope of Study
12


Methods 12


Results 14


Discussion 21


Limitations 22


Conclusion and Recommendation
23


References 24


Annex I
27


Annex II
28




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Risk Assessment Studies
Report No. 36







The Food Safety of Instant Cup Noodle
Containers





1

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EXECUTIVE SUMMARY


The Centre for Food Safety (CFS) has conducted a study to assess the safety
and suitability of instant cup noodles (ICN) containers commonly available in
Hong Kong for holding food.

ICN are commonly consumed in Hong Kong. The safety of ICN containers
raised public concern following media reports on unsafe disposable containers.
The primary concern of the containers for ICN is the migration of harmful
substances from the containers into the food. Also, ICN containers should not
leach out into the food an unacceptable quantity of their components because even
if they are non-toxic, they may change the composition and affect the quality of
the food.

Some chemical residues if present in the ICN containers may lead to health
risk if they are migrated to food. Those of most concern are styrene monomer
which is used to make polystyrene (PS), heavy metals which are impurities, and
diaminotoluene, a contaminant that may remain in lids of ICN made of composite
laminated films.

There are other substances such as additives, impurities, reaction products
and breakdown products of the contact material of ICN that may migrate into the
food. Measuring the specific levels of all these substances in food may not be
feasible. However, the total amount of migration of all these substances to food
can be reflected by the total migration level.

Study on Containers of ICN and Food Safety
2

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Sampling was carried out from March to May 2008. Laboratory analysis
was conducted by the Food Research Laboratory of the CFS. A total of 52 ICN
products coming from a number of countries and areas were sampled in local
supermarkets, chain stores, department stores, and grocery stores for identification
of the contact materials in these cups and lids. Among which, 30 ICN products
of most common brands available in supermarkets and chain stores were selected
for the testing of safety and suitability. The testing parameters included total
migration, heavy metals, styrene monomers and diaminotoluene.

Results
The Identification test revealed that the cups of ICN were made of
polyethylene (PE) coated paper, expanded polystyrene (EPS), and polypropylene
(PP). As for the lids, they were made of PS, PP, as well as composite laminated
films with PE, PS, or co-polymers contact surfaces.

A total of 30 sets of cup and lid from the ICN products were tested for total
migration. All levels detected were well below the limit of 0.5 mg/inch2 set by
the US Food and Drug Administration (FDA). None of the samples were found
to contain heavy metals. A total of 11 cups and 5 lids made of PS, EPS, or
contain PS coating, were tested for styrene monomer. The levels of styrene
monomer ranged from not detected to 1000 mg/kg (0.1% by weight) which were
within the limit of 0.5 % by weight of total residual styrene monomer set by the
US FDA. No diaminotoluene was detected in any lids made of composite
laminated films.

Conclusion and recommendation
Results of this study showed that the containers of ICN complied with the
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standards for total migration and styrene monomer set by US FDA as well as
heavy metals and diaminotoluene set by the Mainland. Under proper usage, these
containers are unlikely to cause food safety problem and are suitable for their
intended use.

Advice to consumers
1. Follow instructions on the ICN package properly.
2. Do not microwave cup noodles unless microwave cooking directions are
specified on the packaging.
3. Never prepare noodles with boiling water in damaged or deformed
containers.

Advice to the trade
1. Obtain containers from manufacturers who follow good manufacturing
practice (GMP).
2. Choose containers that are safe and suitable for the intended use.
3. State the instruction and warning for the preparation of the noodles clearly on
the package.



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Risk Assessment Studies –


The Food Safety of Instant Cup Noodle Containers


OBJECTIVE


This study aims to assess the safety and suitability of instant cup
noodles (ICN) containers commonly available in Hong Kong for holding
food.

BACKGROUND
2.
In recent years, there have been media reports saying that some
disposable plastic containers were found to contain toxic substances
which might leach out from the containers and be released into the food.
These reports aroused public concern in Hong Kong about food safety of
the disposable containers. In response, the Centre for food safety (CFS)
and the Consumer Council jointly conducted a study on disposable plastic
containers for take-away meals to assess the local situation in 2005. The
results showed that there was no safety concern on all the containers
tested.1

3.
Besides take-away meals, ICN are also packaged with disposable
containers. ICN are commonly consumed in Hong Kong and the safety
of their containers has also received attention. There have been
enquiries from the public to the CFS about the safety of ICN containers
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and requesting laboratory tests to be conducted on these products. In
view of this, the CFS has conducted a study to examine for the safety and
suitability of the ICN containers.

4.
The common brands of ICN sold in major supermarkets and
chain stores are mainly produced in the Mainland, Taiwan, Thailand or
locally. There are also a variety of less common products that are
mainly produced in Japan, Korea, and other Asian countries. They are
available in certain Japanese-style department stores, Southeast Asia-style
grocery stores, or high-end supermarkets.

5.
According to the labels, the cups of ICN are mainly made of
polyethylene (PE) coated paper, expanded polystyrene (EPS)/foamed PS,
and polypropylene (PP) plastic. As for the lids, the majority of them are
heat-sealable liddings made of laminated films composed of paper,
aluminum foil, and plastics. The rest of the lids are made of PP, PS
plastics.

Safety of ICN containers
6.
The degree of migration depends on various factors including
chemical nature of substances in materials, concentrations of substances,
volume of food per unit area of material, the type of food and beverage,
the temperature during contact, and the contact time.2 Migration into
liquid foods will be higher than that into more solid foods, particularly
dry food. Studies have shown that migration of styrene monomer was
higher with fatty foods than with aqueous foods.3 With all plastic types,
migration increases with temperature and time of contact.
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