Food-Contact Materials and Articles - ACS Symposium Series (ACS

Chapter 9

Food-Contact Materials and Articles Standards for Europe

Downloaded by UNIV OF CALIFORNIA SAN DIEGO on January 19, 2017 | http://pubs.acs.org Publication Date: September 13, 1991 | doi: 10.1021/bk-1991-0473.ch009

J. F. Kay Food Science Division I, Ministry of Agriculture, Fisheries, and Food, Ergon House, Nobel House, 17 Smith Square, London SW1P 3JR, United Kingdom

As part of its programme to create a Single European Market, the European Commission is harmonising rules governing materials and articles intended to come into contact with foodstuffs in order to remove technical barriers to trade and to protect the consumer. A framework Directive was adopted under which specific directives relating to particular food contact materials could be adopted. The key provisions of this Directive are that materials should be manufactured in accordance with good manufacturing practice and not endanger human health in use. Specific Directives already exist, e.g. on vinyl chloride monomer and regenerated cellulose film (cellophane). The recently adopted Plastics Directive lays down a positive list of monomers which can be used to manufacture food contact plastics. Future directives will include paper and board, already at an advanced stage of consideration by the Council of Europe (a non EC body), plus further plastics work. There is an active co-ordinated surveillance programme of work in the U.K. providing scientific data to assist the above bodies in proposals for future legislation. It i s important to remember when considering l e g i s l a t i o n i n the food and food packaging sectors what i t s primary aims are. In the food packaging industry i t can generally be said that i t i s Intended to ensure that the packaging results i n food being safe, wholesome and of the nature, substance and quality demanded by the purchaser. The maintenance of a safe and nutritious food supply has long been regarded as a matter of the utmost importance i n the United Kingdom, as i n many other countries. Indeed, the f i r s t Sale of Food and Drugs Act was enacted well over 100 years ago. Since that time l e g i s l a t i o n on food has continually been updated to take account of new developments. 0097-6156/91/0473-0104506.00/0 © 1991 American Chemical Society

Risch and Hotchkiss; Food and Packaging Interactions II ACS Symposium Series; American Chemical Society: Washington, DC, 1991.

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To ensure t h a t food s a f e t y l e g i s l a t i o n affords adequate and e f f e c t i v e consumer p r o t e c t i o n , l e g i s l a t i o n must be based on sound, scientific principles. T h i s i s the UK Government p h i l o s o p h y and i n consequence an e x t e n s i v e a d v i s o r y system has been established u t i l i s i n g e x t e n s i v e i m p a r t i a l , independent, s c i e n t i f i c and m e d i c a l o p i n i o n on a l l s a f e t y - r e l a t e d a s p e c t s o f f o o d , i n c l u d i n g food p a c k a g i n g . T h i s system i s i n c r e a s i n g l y p r o v i d i n g d a t a f o r use i n n e g o t i a t i o n s i n the European Community.


Controls on Pood Packaging The p r i n c i p l e reasons f o r the use o f food p a c k a g i n g a r e t o a l l o w f o r the h y g i e n i c h a n d l i n g o f f o o d , p r e v e n t m i c r o b i a l c o n t a m i n a t i o n and more r e c e n t l y through m o d i f i c a t i o n o f the atmosphere around the c o n t a i n e d f o o d , t o extend the s h e l f - l i f e . However, the package i t s e l f can r e p r e s e n t a source o f c h e m i c a l c o n t a m i n a t i o n t h r o u g h the transfer, o r more a c c u r a t e l y m i g r a t i o n , o f s u b s t a n c e s from the p a c k a g i n g m a t e r i a l i n t o the f o o d . Many r e g u l a t o r y a u t h o r i t i e s around the w o r l d have r e c o g n i s e d t h a t i t i s n e c e s s a r y t o c o n t r o l t h i s m i g r a t i o n and have enacted e x t e n s i v e l e g i s l a t i o n . Much o f t h i s l e g i s l a t i o n i n c l u d e s p o s i t i v e l i s t s o f p e r m i t t e d substances t o g e t h e r with appropriate r e s t r i c t i o n s . A l i m i t on the t o t a l m i g r a t i o n o f t h e c o n s t i t u e n t s o f the m a t e r i a l , known as the g l o b a l o r o v e r a l l m i g r a t i o n , may a l s o be i n c l u d e d . EC L e g i s l a t i o n on Pood Contact Materials As p a r t o f i t s programme t o c r e a t e a S i n g l e European M a r k e t , t h e EC i s d r a w i n g up r u l e s g o v e r n i n g m a t e r i a l s and a r t i c l e s i n t e n d e d t o come i n t o contact with foodstuffs i n o r d e r both t o remove t e c h n i c a l b a r r i e r s t o t r a d e and t o p r o t e c t the consumer. The s t a r t i n g p o i n t was t o e s t a b l i s h a framework d i r e c t i v e under which s p e c i f i c d i r e c t i v e s r e l a t i n g t o p a r t i c u l a r food c o n t a c t m a t e r i a l s c o u l d be a d o p t e d . The key p r o v i s i o n o f the m a t e r i a l s and a r t i c l e s framework D i r e c t i v e 89/109/EEC and o f UK R e g u l a t i o n s implementing i t (The M a t e r i a l s and A r t i c l e s i n Contact w i t h Food R e g u l a t i o n s 1987 [ S . I . 1987 No. 1523]) i s t h a t m a t e r i a l s and a r t i c l e s s h a l l be manufactured i n accordance w i t h good m a n u f a c t u r i n g p r a c t i c e , i . e . i n such a way t h a t under normal o r f o r e s e e a b l e c o n d i t i o n s o f use they do not t r a n s f e r t h e i r c o n s t i t u e n t s t o foods w i t h which t h e y a r e , o r a r e l i k e l y t o be, i n c o n t a c t , i n q u a n t i t i e s which c o u l d : (i) (ii)

endanger human h e a l t h , o r bring about a deterioration in the organoleptic c h a r a c t e r i s t i c s o f such food o r an u n a c c e p t a b l e change i n i t s n a t u r e , s u b s t a n c e or q u a l i t y .

In o r d e r t o r e i n f o r c e i t s g e n e r a l p r o v i s i o n s , the framework D i r e c t i v e p r o v i d e s f o r s p e c i f i c d i r e c t i v e s t o be developed for i n d i v i d u a l food c o n t a c t m a t e r i a l s , i n c l u d i n g paper and b o a r d , and lists the v a r i o u s measures t h a t t h e s e d i r e c t i v e s may i n c l u d e . D i r e c t i v e s have a l r e a d y been agreed w h i c h l a y down l i m i t s on the r e l e a s e o f l e a d and cadmium from c e r a m i c ware ( 8 ^ / 5 0 0 / E E C ) , e s t a b l i s h a p o s i t i v e l i s t o f s u b s t a n c e s t h a t may be used i n the p r o d u c t i o n o f


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r e g e n e r a t e d c e l l u l o s e f i l m ( 8 3 / 2 2 9 / E E C ) ; c o n t r o l the m i g r a t i o n o f g l y c o l s from such f i l m ( 8 6 / 3 3 8 / E E C ) , and s p e c i f y the symbols w h i c h may be used t o accompany food c o n t a c t m a t e r i a l s and a r t i c l e s (80/590/EEC). A series of D i r e c t i v e s c o n t r o l l i n g residues o f v i n y l c h l o r i d e monomer have a l s o been adopted ( 7 8 / 1 ^ 2 / E E C ; 80/766/EEC; 8 1 / 4 3 2 / E E C ) . These D i r e c t i v e s have e i t h e r been implemented i n UK law or are b e i n g so implemented. Two D i r e c t i v e s l a y down the b a s i c r u l e s f o r t e s t i n g m i g r a t i o n from p l a s t i c s (82/711/EEC) and, f o r p l a s t i c s intended for contact with specific foodstuffs or groups of f o o d s t u f f s , s p e c i f y which s i m u l a n t s (food s i m u l a t i n g l i q u i d s ) are t o be used i n each case ( 8 5 / 5 7 2 / E E C ) . They a r e r e q u i r e d t o be enacted i n UK law a t the same time as the f i r s t Community p o s i t i v e l i s t . EC Commission D i r e c t i v e 90/128/EEC on food c o n t a c t plastics c o m p r i s e s a l i m i t on o v e r a l l m i g r a t i o n and a p o s i t i v e l i s t o f monomers and o t h e r s t a r t i n g s u b s t a n c e s . T h i s was adopted e a r l i e r t h i s y e a r . Under t h i s D i r e c t i v e p l a s t i c s m a t e r i a l s and a r t i c l e s s h a l l n o t t r a n s f e r t h e i r c o n s t i t u e n t s t o f o o d s t u f f s i n q u a n t i t i e s e x c e e d i n g 10 mg/dm o f s u r f a c e a r e a o f the m a t e r i a l o r a r t i c l e ( o v e r a l l m i g r a t i o n l i m i t ) . However t h i s l i m i t w i l l be 60 mg/kg o f f o o d s t u f f i n c e r t a i n cases. The second a s p e c t o f t h e D i r e c t i v e comprises a p o s i t i v e l i s t o f monomers and o t h e r s t a r t i n g s u b s t a n c e s . A l l o f the monomers and o t h e r starting substances have been evaluated by t h e Commission*s t o x i c o l o g i c a l a d v i s o r y committee, the S c i e n t i f i c Committee f o r Food ( S C F ) . Substances which e x h i b i t some t o x i c i t y but which a r e e s s e n t i a l f o r polymer manufacture, a r e s u b j e c t t o s t r i n g e n t l i m i t s , e i t h e r i n the p l a s t i c o r i n the food and such l i m i t s i n c o r p o r a t e a l a r g e s a f e t y f a c t o r r e d u c i n g f u r t h e r the l e v e l w h i c h would be a c c e p t a b l e on t o x i c o l o g i c a l grounds i n the w o r s t m i g r a t i o n s i t u a t i o n . Substances f o r w h i c h t h e r e were i n s u f f i c i e n t t o x i c o l o g i c a l o r t e c h n o l o g i c a l d a t a t o enable a judgement t o be expressed w i l l be re-examined by the SCF i n a r o l l i n g programme up t o 1992. Any substance t h a t cannot be e v a l u a t e d f a v o u r a b l y w i l l be d e l e t e d from the D i r e c t i v e , a p a r t from t h o s e substances s u b j e c t t o l o n g term t e s t i n g , f o r which a d e a d l i n e o f 1996 has been s e t . 2

The UK approach I t has l o n g been r e c o g n i s e d i n the UK t h a t one o f the p r i n c i p l e p r o t e c t i o n s f o r the consumer from any h a z a r d a r i s i n g from the presence o f contaminants i n food i s the e x i s t e n c e o f a v i g i l a n t and responsible industry, and its w i l l i n g n e s s to co-operate with Government i n t h i s a r e a . As p a r t o f t h i s p r o c e s s o f c o - o p e r a t i o n , i t has been u s u a l t o i n v o l v e the food and food p a c k a g i n g i n d u s t r i e s i n any o f f i c i a l i n f o r m a t i o n - g a t h e r i n g e x e r c i s e s , d e s i g n e d t o a s s e s s the l e v e l s o f c o n t a m i n a t i o n o f food which might a r i s e from the use o f food c o n t a c t m a t e r i a l s . Such e x e r c i s e s have n o r m a l l y been u n d e r t a k e n as p a r t o f MAFF s food s u r v e i l l a n c e programme and overseen by a s e n i o r UK Government i n t e r d e p a r t m e n t a l a d v i s o r y body, the S t e e r i n g Group on Food S u r v e i l l a n c e (SGFS). T h i s body has a r e m i t t o keep under r e v i e w the p o s s i b i l i t i e s o f c o n t a m i n a t i o n o f any p a r t o f t h e UK food s u p p l y and t o r e v i e w where n e c e s s a r y the i n t a k e o f i n d i v i d u a l a d d i t i v e s and n u t r i e n t s . Recommendations are made to Ministers r e s p o n s i b l e f o r food q u a l i t y and s a f e t y on the programme o f work 1



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n e c e s s a r y t o ensure t h a t the food i n t a k e o f the p o p u l a t i o n i s b o t h s a f e and n u t r i t i o u s . The work o f t h i s S t e e r i n g Group w i l l c o n t i n u e p r i m a r i l y t o p r o v i d e new i n f o r m a t i o n w h i c h can be fed back i n t o the s t a t u t o r y c o n t r o l system t o produce m o d i f i e d o r new l e g i s l a t i o n as necessary. F o l l o w i n g the c a r r y i n g out o f a number o f s u c c e s s f u l ad-hoc e x e r c i s e s i n the 1970s on monomers o f t o x i c o l o g i c a l c o n c e r n , the SGFS d e c i d e d t h a t i t would be a p p r o p r i a t e t o e s t a b l i s h a w o r k i n g p a r t y t o keep under r e v i e w the p o s s i b i l i t y o f c o n t a m i n a t i o n o f any p a r t o f the UK food s u p p l y by c h e m i c a l s a r i s i n g from food c o n t a c t m a t e r i a l s . Thus the Working P a r t y on Chemical Contaminants from Food Contact M a t e r i a l s was e s t a b l i s h e d d u r i n g 1984, w i t h a membership drawn l a r g e l y from manufacturers and u s e r s o f such m a t e r i a l s . In i t s f i r s t y e a r the Working P a r t y t a c k l e d a number o f m a t t e r s o f immediate i m p o r t a n c e , n o t a b l y p l a s t i c i s e r s . A Sub-group was s e t up t o undertake an i n - d e p t h e x a m i n a t i o n o f t h e s e m a t e r i a l s and i t s f i n d i n g s have been p u b l i s h e d as Food S u r v e i l l a n c e Paper No. 21 ( 1 ) . One p a r t i c u l a r a s p e c t o f t h i s Report d e a l t w i t h cling film and the m i g r a t i o n o f i t s p l a s t i c i s e r s , e s p e c i a l l y d u r i n g microwave c o o k i n g . The work o f t h i s Sub-group, t o g e t h e r w i t h t o x i c o l o g i c a l e v a l u a t i o n , e n a b l e d guidance t o be g i v e n t o the p u b l i c on the use o f such c l i n g - w r a p m a t e r i a l s p a r t i c u l a r l y i n microwave c o o k i n g and f o r the i n d u s t r y t o use t h i s as a p l a t f o r m t o develop new m a t e r i a l s w i t h a l o w e r m i g r a t i o n p o t e n t i a l . A second r e p o r t on t h i s t o p i c w i l l be p u b l i s h e d l a t e r t h i s y e a r . Other Sub-groups have been e s t a b l i s h e d by t h e Working P a r t y t o undertake i n - d e p t h r e v i e w s o f c o l o u r a n t s and aids to polymerisation with the objective of drawing up recommendations on the usage o f such substances. Having now s u c c e s s f u l l y completed t h e i r programmes o f work, the Sub-groups on P l a s t i c i s e r s and a l s o A i d s t o P o l y m e r i s a t i o n have been d i s b a n d e d . Another Sub-group i s c a r r y i n g out a s u r v e y on the uses o f food c o n t a c t paper and board w i t h the i n t e n t i o n o f c a l c u l a t i n g d i e t a r y i n t a k e s o f any components o f paper and board t h a t m i g r a t e i n t o foodstuffs. The presence o f d i o x i n s i n paper and board and i n food i n c o n t a c t w i t h t h e s e m a t e r i a l s has been i n v e s t i g a t e d by t h i s group and does not appear to pose a problem as l e v e l s are v e r y l o w . A Food S u r v e i l l a n c e Paper s i m i l a r t o t h a t produced on p l a s t i c i s e r s i s i n preparation on t h i s topic. P r e l i m i n a r y data on d i o x i n levels m i g r a t i n g from food c o n t a c t paper and board have been p u b l i s h e d i n Department o f the Environment P o l l u t i o n Paper No. 27 ( 2 ) . A f i f t h Sub-group was e s t a b l i s h e d w i t h a r e m i t t o c o n s i d e r food c o n t a c t m a t e r i a l s i n t o t o and e l a b o r a t e a coherent s t r a t e g y f o r t h e i r systematic examination. T h i s Sub-group has completed i t s s t u d y and i t s r e p o r t has been i n c l u d e d i n Food S u r v e i l l a n c e Paper No. 26 ( 3 ) . An i m p o r t a n t a s p e c t o f a l l o f the Working P a r t y ' s work i s the c o m m i s s i o n i n g o f an a p p r o p r i a t e r e s e a r c h programme b o t h w i t h i n and o u t s i d e the M i n i s t r y s own Food S c i e n c e L a b o r a t o r y . In order to produce a r e s e a r c h programme w i t h commonly agreed p r i o r i t i e s , a Sub-group on Research P r i o r i t i e s was e s t a b l i s h e d t o o v e r s e e MAFF's r e s e a r c h programme on food c o n t a c t m a t e r i a l s . The r e s e a r c h u n d e r t a k e n by t h e Working P a r t y between 1984 and 1988 i s a l s o d e t a i l e d i n Food S u r v e i l l a n c e Paper 26 ( 3 ) . 1

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The M i n i s t r y s own Food S c i e n c e L a b o r a t o r y has c a r r i e d out r e s e a r c h on food c o n t a c t m a t e r i a l s s i n c e the m i d - 1 9 7 0 s . T h i s has i n v o l v e d b o t h the p r o v i s i o n o f s u r v e i l l a n c e d a t a on monomer l e v e l s and a l s o i n v e s t i g a t i n g more fundamental potential problem a r e a s . These s t u d i e s have been conducted i n c l o s e c o l l a b o r a t i o n w i t h the p l a s t i c s i n d u s t r y and i n i t i a l l y e s t a b l i s h e d the c h e m i c a l i d e n t i t i e s o f the f u l l range o f i n g r e d i e n t s o f commercial PVC f o r m u l a t i o n s . In r e c e n t y e a r s work has been c a r r i e d out i n support o f v a r i o u s Sub-groups or i n c o l l a b o r a t i o n w i t h o u t s i d e c o n t r a c t o r s . Many d a t a have r e c e n t l y been generated f o r the f o r t h c o m i n g Second Report o f the Sub-group on P l a s t i c i s e r s . Methods have been developed t o measure e p o x i d i s e d soya bean o i l (ESBO) and p o l y m e r i c p l a s t i c i s e r s i n b o t h p l a s t i c s and f o o d s . P h t h a l a t e s are used i n p r i n t i n g i n k s and t h e i r m i g r a t i o n i n t o foods have been d e t e r m i n e d . The e f f e c t o f a s e p t i c p r o c e s s i n g on m i g r a t i o n has been s t u d i e d . Both o v e r a l l m i g r a t i o n and the m i g r a t i o n o f a s p e c i f i c a n t i o x i d a n t from p o l y p r o p y l e n e p o t s t r e a t e d w i t h a commercial s t r e n g t h hydrogen p e r o x i d e s o l u t i o n have been measured. A n t i o x i d a n t m i g r a t i o n from the p o t s does not appear t o depend on t r e a t m e n t . Microwave oven usage has become i n c r e a s i n g l y p o p u l a r i n the UK o v e r the p a s t few y e a r s and t h i s has r e s u l t e d i n a wide range o f p l a s t i c s cookware b e i n g s p e c i f i c a l l y produced f o r use i n t h e s e o v e n s . The Food S c i e n c e L a b o r a t o r y has s e t up a programme t o examine the m a t e r i a l s used t o f a b r i c a t e t h e s e cookware items and i n i t i a l l y has c o n c e n t r a t e d upon p o l y ( v i n y l i d e n e c h l o r i d e ) f i l m and p o l y e t h y l e n e terephthalate trays. S i n c e e x i s t i n g E C - l a i d down t e s t i n g c o n d i t i o n s do not r e f e r t o microwave usage, a p r o t o c o l f o r t e s t i n g m a t e r i a l s i n t e n d e d f o r use i n microwave ovens i s a l s o b e i n g e s t a b l i s h e d . S u s c e p t o r m a t e r i a l s i n t e r a c t w i t h microwave energy t o a c h i e v e h i g h t e m p e r a t u r e s v e r y r a p i d l y and a r e i n t e n d e d f o r browning and c r i s p i n g a p p l i c a t i o n s such as c o o k i n g p o t a t o c h i p s and p a s t r i e s . S t u d i e s have shown t h a t the m i g r a t i o n o f PET o l i g o m e r s from s u s c e p t o r pads i s low ( 4 ) . T o t a l l e v e l s o f m i g r a t i o n o f PET o l i g o m e r s were found t o range from 0.02 t o 2.73 mg/kg, depending on the f o o d s t u f f and the temperature a t t a i n e d during cooking. Further studies are being conducted i n t o the p o t e n t i a l m i g r a n t s from the a d h e s i v e and p u l p b o a r d l a y e r s o f these m a t e r i a l s . S t u d i e s on r e p e a t - u s e a r t i c l e s have r e s u l t e d i n a change o f EC proposals for migration t e s t i n g o f these a r t i c l e s . The t h i r d t e s t i s now a p p l i c a b l e f o r a l l m a t e r i a l s i n t e n d e d f o r r e p e a t - u s e u n l e s s t h e r e is evidence t h a t m i g r a t i o n does not increase with successive exposures. A n a l y s t s w i l l r e q u i r e s t a n d a r d samples o f p l a s t i c s and p l a s t i c s a d d i t i v e s t o enable the proposed EC l e g i s l a t i o n on food c o n t a c t p l a s t i c s t o be e n f o r c e d . The f e a s i b i l i t y o f e s t a b l i s h i n g a r e f e r e n c e c o l l e c t i o n o f s t a n d a r d samples i s b e i n g e x p l o r e d . The UK government i s c u r r e n t l y u n d e r t a k i n g a r e v i e w on the uses o f m i n e r a l hydrocarbons i n cheese waxes and food c o n t a c t materials. M i g r a t i o n o f t h e s e s u b s t a n c e s i n t o cheeses and i n t o s k i n l e s s sausages (as a r e s u l t o f t h e i r use on sausage c a s i n g s ) has been s t u d i e d . The f e a s i b i l i t y o f p r o d u c i n g p l a s t i c s e x t r a c t s under c o n d i t i o n s r e p r e s e n t a t i v e o f normal usage i s under c o n s i d e r a t i o n . T h i s would


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enable t o x i c o l o g i c a l t e s t i n g t o be c a r r i e d out not j u s t on i n d i v i d u a l components, but on the t o t a l e x t r a c t o f t h e p l a s t i c , i n c l u d i n g transformation products. S i n c e the e a r l y 1980s, p r o j e c t s have* been p l a c e d w i t h o u t s i d e c o n t r a c t o r s t o supplement t h o s e b e i n g c a r r i e d out i n the Food S c i e n c e Laboratory. A l t h o u g h a c o n s o l i d a t e d r e s e a r c h programme c o u l d not be e s t a b l i s h e d i m m e d i a t e l y , t h i s was seen as the u l t i m a t e o b j e c t i v e and the l a s t few y e a r s have seen c o n s i d e r a b l e p r o g r e s s towards t h i s g o a l . Some o f t h e s e s t u d i e s are d e s c r i b e d below. Assessment o f consumer exposure t o the d i f f e r i n g types o f primary ( r e t a i l ) packaging. The o b j e c t i v e o f t h i s study was to determine the s u r f a c e a r e a o f each type o f p a c k a g i n g m a t e r i a l coming i n t o c o n t a c t w i t h the ' a v e r a g e diet. T h i s i n f o r m a t i o n w i l l prove i n v a l u a b l e i n the e s t i m a t i o n o f intakes o f migrants. I n the f u t u r e t h i s p r o j e c t w i l l be extended t o cover caps and c l o s u r e s and beverages. 1

Mathematical and physical models o f migration. The various m a t h e m a t i c a l and p h y s i c a l models t h a t have been developed around the w o r l d t o p r e d i c t m i g r a t i o n have been c r i t i c a l l y r e v i e w e d . I n the second phase o f t h i s work, the l o n g - t e r m o b j e c t i v e i s t o d e v e l o p a l i m i t e d number o f models which w i l l c o v e r the b e h a v i o u r o f the m a j o r i t y o f cases o f p r a c t i c a l i n t e r e s t , leading to a basis for l e g i s l a t i o n regarding migration l i m i t s . 1

The release o f contaminants by leaching from ' b o i l - i n bags. F o l l o w i n g i n i t i a l s t u d i e s on the e f f e c t o f polymer morphology on d i f f u s i o n , s o l u b i l i t y and p e r m e a b i l i t y c o - e f f i c i e n t s , t h i s p r o j e c t c o n c e n t r a t e d upon q u a n t i f y i n g s u b s t a n c e s m i g r a t i n g from boil-in bags under n a t u r a l usage c o n d i t i o n s . The v a r i o u s l a y e r s o f commercial bags were examined i n d i v i d u a l l y s t a r t i n g w i t h the p o l y o l e f i n food contact l a y e r . 1

f

The effect o f gumma- and electron-beam I r r a d i a t i o n on food contact plastics. The e f f e c t o f g a m m a - i r r a d i a t i o n on a d d i t i v e s p r e s e n t i n food c o n t a c t plastics has been examined. Initially organotin stabilisers were studied followed by phenolic and phosphite a n t i o x i d a n t s . A study i s now b e i n g undertaken t o determine the e f f e c t s o f e l e c t r o n - b e a m i r r a d i a t i o n on such a d d i t i v e s . Thermal s t a b i l i t i e s o f polymers used i n food contact plastics. Substances m i g r a t i n g from o v e n a b l e p l a s t i c s under a c t u a l usage c o n d i t i o n s were q u a n t i f i e d w i t h the emphasis being placed on polyethylene terephthalate t r a y s . f

f

Examination o f the p o s s i b i l i t y o f s e t t i n g t e s t i n g p r i o r i t i e s f o r substances used i n food contact materials. The c o r r e l a t i o n between c h e m i c a l s t r u c t u r e and t o x i c i t y i s b e i n g i n v e s t i g a t e d f o r s u b s t a n c e s on the d r a f t EC p o s i t i v e l i s t s o f monomers and p l a s t i c s a d d i t i v e s . Quantitative Structure A c t i v i t y R e l a t i o n s h i p s (QSARs) a r e being developed f o r such s u b s t a n c e s , w i t h the aim o f p r i o r i t i s i n g t h e s e substances for f u r t h e r study. The r e s e a r c h

programme

is

b e i n g widened t o

i n c l u d e the

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m i g r a t i o n from food c o n t a c t m a t e r i a l s a t e l e v a t e d t e m p e r a t u r e s and m i g r a t i o n from m e t a l c o n t a i n e r s . L i a i s o n between c o n t r a c t o r s i s s t r o n g l y encouraged i n o r d e r t o s h a r e e x p e r t i s e and a v o i d d u p l i c a t i o n o f e f f o r t . An a n n u a l meeting i s h e l d a t w h i c h c o n t r a c t o r s summarise p r o g r e s s d u r i n g t h e p r e c e d i n g y e a r . I n o r d e r t o ensure t h a t t h e work i s c o m m e r c i a l l y r e l e v a n t , a n i n d u s t r i a l r a p p o r t e u r i s a p p o i n t e d t o each p r o j e c t t o a s s i s t t h e Ministry's project officer. These rapporteurs have appropriate s p e c i a l i s t or i n d u s t r i a l knowledge and a r e i n v o l v e d w i t h a p r o j e c t a t a l l s t a g e s from finalising t h e o b j e c t i v e s and i d e n t i f y i n g potential contractors t h r o u g h t o recommending f u r t h e r work. To date t h i s system has proved highly successful with contractors generally reacting very favourably towards i t . Conclusions Up u n t i l now, t h e UK has opted f o r a b a s i c s t a t u t o r y framework combined w i t h a m o n i t o r i n g programme c a r r i e d o u t w i t h t h e s u p p o r t o f i n d u s t r y . I n t h e next few y e a r s , more e x t e n s i v e l e g i s l a t i o n w i l l be adopted as p a r t o f t h e E C ' s h a r m o n i s a t i o n programme. I t i s e s s e n t i a l t h a t such l e g i s l a t i o n i s based on good s c i e n c e and t h e UK w i l l c o n t i n u e i t s e x t e n s i v e s u r v e i l l a n c e and r e s e a r c h programme t o a c h i e v e t h i s . The i m p l i c a t i o n s o f f o r t h c o m i n g EC l e g i s l a t i o n a r e b e i n g discussed with Industry.

Literature Cited 1 Ministry of Agriculture, Fisheries and Food; Survey of plasticiser levels in food contact materials and in foods; Food Surveillance Paper No. 21; HMSO: London, UK, 1987. 2 Department of the Environment; Dioxins in the Environment; Pollution Paper No. 27; HMSO: London, UK, 1989. 3 Ministry of Agriculture, Fisheries and Food; Migration of substances from food contact materials into food; Food Surveillance Paper No. 26; HMSO: London, UK, 1989. 4 Castle, L., Mayo, A.K., Crews, C. and Gilbert, J. J. Food Protect. 1989, 52, 337-342. R E C E I V E D April25,1991


Food-Contact Materials and Articles - ACS Symposium Series (ACS

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