STATUTORY INSTRUMENTS.

S.I. No. 337 of 1981.

HEALTH (PRESERVATIVES IN FOOD) REGULATIONS 1981.

S.I. No. 337 of 1981.

HEALTH (PRESERVATIVES IN FOOD) REGULATIONS 1981.

The Minister for Health, in exercise of the powers conferred on her by sections 5, 54, 56 and 59 of the Health Act, 1947 (No. 28 of 1947) , sub-section (3) of section 38 of the Health Act, 1953 ( No. 26 of 1953 ) and section 6 of the Health Act, 1970 ( No. 1 of 1970 ), after consultation with the Minister for Industry and Energy, the Minister for Trade, Commerce and Tourism and the Minister for Agriculture hereby makes the following Regulations:-

1. These Regulations may be cited as the Health (Preservatives in Food) Regulations, 1981.

2. These Regulations shall come into operation on the 1st day of October, 1981.

3. (1) The Health (Preservatives in Food) Regulations, 1973 ( S.I. No. 147 of 1973 ) are hereby revoked.

(2) The provisions of Articles 9 to 12 of the Health (Arsenic and Lead in Food) Regulations, 1972 ( S.I. No. 44 of 1972 ) shall not apply to any permitted preservative.

4. (1) In these Regulations--

“the Act” means the Health Act, 1947 ;

“approved examiner” means a public analyst or any person approved, or person of a class approved, by the Minister for Health to analyse food for the purpose of regulations made under Part V of the Act;

“authorised officer” means an authorised officer for the purpose of Part IX of the Act;

“container” includes any form of packaging of food and any wrapper or band;

“food” has the meaning assigned to it in Part V of the Act;

“permitted preservative” means any preservative described in Part I and Part II of Schedule 2 to these Regulations which complies with the specific purity criteria in relation to that preservative specified in the European Communities (Preservatives in Food) (Purity Criteria) Regulations, 1981 ( S.I. No. 184 of 1981 ) and with the general purity criteria contained in Schedule 3 to these Regulations;

“pre-packed” means made up in a container for the purpose of retail sale prior to sale;

“preparation”, in relation to food, includes manufacture and any form of treatment;

“preservative” means any substance which is capable of inhibiting, retarding or arresting deterioration of food caused by micro-organisms and of concealing the evidence of any such deterioration but does not include--

(a) any substance (other than, where used on raw meat, L-ascorbic acid and any salt or other derivative of the said acid) the use of which is permitted under Regulations other than these Regulations, for the time being in force under Part V of the Act;

(b) common salt;

(c) sugars;

(d) nicotinic acid and its amide where used otherwise than on raw meat;

(e) vinegar, malic acid, polyphosphoric acid, erythorbic acid and the calcium, sodium and potassium salts of any of the said acids (but excluding, where used on raw meat, erythorbic acid and any salt or other derivative of that acid);

(f) potable spirits;

(g) herbs and hop extract;

(h) spices and essential oils used for flavouring purposes;

(i) any substance added to food by smoking;

(j) nitrogen or hydrogen used in the packaging of food in hermetically sealed containers;

(k) nitrous oxide used in the making of whipped cream;

“sell” includes supply, offer or expose for sale or have in possession for sale and cognate words shall be construed accordingly;

“smoking” means treating food with smoke or smoke solutions derived from wood or ligneous vegetable matter, in the natural state, other than wood or ligneous vegetable matter which has been impregnated, coloured, gummed, painted or otherwise treated in a similar manner;

“specified food” means any food of a description specified in column 1 of Schedule 1 to these Regulations;

(2) Unless a contrary intention is expressed, all proportions mentioned in these Regulations are calculated by the weight of the product as manufactured, prepared, imported, distributed or sold.

(3) Any reference in these Regulations to any other Regulations shall be construed as a reference to such Regulations as amended by subsequent Regulations.

(4) Any reference in these Regulations to a label borne on a container shall be construed as including a reference to any legible marking on the container however effected.

5. For the purposes of these Regulations, the supply of food, otherwise than by sale, at, in or from any place where food is supplied in the course of a business shall be deemed to be a sale of that food.

6. Any reference in these Regulations to an owner or to a person responsible for food shall, in the case of food purchased from an automatic machine, be construed as a reference--

(a) where the name and address of the proprietor is stated on the machine and such address is in the State, to the proprietor of the machine;

(b) in other cases, to the occupier of the premises at or on which the machine stands or to which it is affixed.

7. These Regulations shall not apply to any food or preservative which is intended to be exported or re-exported.

8. These Regulations shall be enforced in the functional area of a health board by the health board.

9. (1) Where a sample of any food has been certified under the Health (Sampling of Food) Regulations, 1970 ( S.I. No. 50 of 1970 ) not to comply with these Regulations, an authorised officer may seize, remove and detain such food as being food which is unfit for human consumption.

(2) With the consent in writing of the owner or person responsible for such food an authorised officer may destroy or otherwise dispose of it so as to prevent its use for human consumption.

(3) An authorised officer who has seized any food in pursuance of the provisions of this article may, on giving notice in writing to the owner or person responsible for such food of his intention to do so, apply to a Justice of the District Court for an order directing that such food be destroyed or otherwise disposed of as being food which is unfit for human consumption.

(4) A Justice of the District Court to whom the application is made for an order under sub-article (3) of this article shall, if satisfied that such food does not comply with these Regulations, order that it be destroyed or otherwise disposed of after such period, not exceeding fourteen days, as may be specified in such order, as being food which is unfit for human consumption and an authorised officer shall destroy or dispose of it accordingly.

(5) A person shall give to any authorised officer all reasonable assistance that the officer may require in the performance of his duties under these Regulations and such assistance shall include the giving of information relating to the composition and use of any food and the identity of the person from whom or the place from which any such food has been obtained and the person to whom and the place to which it has been consigned or the manner in which it has otherwise been disposed of.

10. A person shall not manufacture, prepare, import, distribute or sell any preservative, other than a permitted preservative.

11. (1) Subject to the provisions of these Regulations, a person shall not manufacture, prepare, import, distribute or sell any food which contains any preservative other than a permitted preservative described in Part II of Schedule 2 to these Regulations.

(2) These Regulations shall not apply to the products defined by Regulation 3 of the Food Standards (Fruit Juices and Fruit Nectars) (European Communities) Regulations 1978 ( S.I. No. 173 of 1978 ) or to the sugars defined by the Food Standards (Certain Sugars) (European Communities) Regulations, 1975 ( S.I. No. 118 of 1975 ).

12. (1) Any specified food may contain a permitted preservative described in relation to such food in column 2 of Schedule 1 to these Regulations provided the amount of the preservative does not exceed that specified in column 3 of the said Schedule in relation to such food and no other permitted preservative.

(2) Any specified food in relation to which two or more permitted preservatives are described in column 2 of Schedule 1 to these Regulations may contain a mixture of those permitted preservatives if the sum of the amounts, or in the case of meat, cured, (including bacon or ham) the amount, of each such permitted preservative in the food expressed as a percentage of the maximum amount permitted by these Regulations of such permitted preservative is not greater than one hundred.

(3) Any food which contains any specified food (other than unfermented grape juice products intended for sacramental use) shall not contain an amount of the permitted preservative exceeding that permitted by these Regulations for such specified food provided that where the specified food contains sulphur dioxide the food containing such specified food may contain either the amount of sulphur dioxide permitted by these Regulations for the specified food or fifty parts per million, whichever is the greater.

(4) A permitted preservative described in column 4 of Schedule 2 to these Regulations, may be used, subject to any conditions of use specified in respect of that preservative contained in column 5 of the said Schedule, instead of the preservative described in relation thereto in column 2 of that Schedule and any reference in these Regulations to any preservative described in column 2 of Schedule 2 shall be construed accordingly.

(5) Any food (other than pre-packed food) which is manufactured, prepared, imported, distributed or sold otherwise than by retail for use in the preparation of food may contain a permitted preservative, or permitted preservatives, exceeding the amount specified in these Regulations if it is packed in a container bearing a label which complies with the requirements for such a label specified in Schedule 5 to these Regulations.

13. (1) Notwithstanding sub-article (1) of Article 12 of these Regulations, the permitted preservatives described in Schedule 2 to these Regulations under Serial Numbers E 230, E 231, E 232 and E 233 may be contained only on the surface of the specified foods described in column 1 of Schedule 1 to these Regulations in relation to such preservatives.

(2) A person shall not manufacture, prepare, import, distribute or sell a specified food which has on it a permitted preservative referred to in sub-article (1) of this article unless--

(a) in the case of sale by retail, prepacked, there appears on a label attached to or borne on the container of the food or, in the case of a sale, other than prepacked, by retail, there appears on a ticket displayed on or in immediate proximity to the food, the words “Treated with preservative”;

(b) in the case of a sale otherwise than by retail there appears on one exterior surface of the container and on the invoice or other document delivered to the purchaser, the words “Treated with biphenyl (E 230)”, “Treated with 2-hydroxybiphenyl (E 231)”, “Treated with sodium biphenyl-2-yl oxide (E 232)” or “Treated with 2-(Thiazol-4-yl) benzimidazole (E 233)”, as appropriate.

14. (1) An authorised officer shall comply with the requirements specified in Part I of Schedule 4 to these Regulations when taking a sample of citrus fruit for the purposes of these Regulations.

(2) The approved examiner or a person under his direction shall assay and determine the content of biphenyl, 2-hydroxybiphenyl and sodium biphenyl 2-yl oxide on citrus fruit in accordance with the methods of analysis specified in Part II of Schedule 4 to these Regulations.

(3) The modified Clevenger-type separator to be used in analysing citrus fruit in accordance with sub-paragraph (2) of this article and Part II of Schedule 4 to these Regulations shall conform with the diagram in Part III of the said Schedule.

15. (1) Subject to the provisions of these Regulations, a person shall not manufacture, prepare, import, distribute, or sell any food [other than beer (including stout and porter) cider and wine (including alcoholic cordials) or food referred to in sub-article (1) of article 13] which contains any permitted preservative described in column 2 of Schedule 1 to these Regulations in respect of such food, unless it is packed in a container bearing a label which complies with the requirements for such a label specified in Schedule 5 to these Regulations or, in the case of a retail sale of food which is not prepacked, a notice to the effect that the food contains preservative is exhibited in a conspicuous place so as to be easily readable by a purchaser of such food.

(2) (a)  In the case of a soft drink as defined in Schedule 1 to these Regulations a label referred to in sub-article (1) of this article may appear on the exposed top surface of the cork, stopper or cap closing the container of such drink.

(b) The provisions of paragraph (a) of sub-article (2) of this article shall cease to have effect on the 31st day of December, 1981.

(3) The provisions of this article shall not apply to--

(a) a specified food which contains sulphur dioxide in a proportion not exceeding fifty parts per million and no other preservative, or

(b) a sale in the course of a catering business of any specified food for immediate consumption.

16. A person shall not import, distribute, or sell any substance for use as a preservative in food unless such substance is packed in a container bearing a label which complies with the requirements for such a label specified in Schedule 5 to these Regulations.

17. (1) A person shall not advertise for sale--

(a) any preservative for use in food which is not a permitted preservative.

(b) any permitted preservatives for use in food or any food containing a permitted preservative in such a manner as to be likely to lead to its use or sale contrary to these Regulations.

(2) Where a person is charged with a contravention of this article, it shall be a good defence to show that the advertisement was published in such circumstances that he did not know and could not, by the exercise of reasonable care, have known that he was taking part in the publication of such advertisement.

SCHEDULE 1

“bread” includes the following and any part of any of the following--baps, bread rolls, fancy bread, milk bread, malt bread and fruit bread;

“carbohydrate” means any substance containing carbon, hydrogen and oxygen only in which the hydrogen and oxygen occur in the same proportion as water;

“cheese spread” means cheese which has been melted and mixed with milk products other than cheese, with or without the addition of emulsifying salts;

“flavouring” includes flavouring essence and flavouring extract and means any product consisting of a flavouring agent and such other substances, if any, the use of which in food is not forbidden and which are reasonably necessary to produce a solid, a solution or an emulsion, but no other ingredient or ingredients;

“flavouring agent” means any sapid or odorous substance capable of imparting and primarily intended to impart a specific and distinctive taste or odour to food, but does not include herbs, spices, onions, garlic, salt, fruit juices, soft drinks, fruit acids, acetic acid, any carbohydrate material, any purine derivative, any preparation of yeast, coffee or chicory or any substances prepared by the hydrolysis of protein-containing materials;

“flavouring syrup” means a solution of carbohydrate sweetening matter containing sufficient flavouring to provide, after dilution with milk or water, a drink with that flavour;

“flour confectionery” means any solid or semi-solid product complete in itself and suitable for consumption without further preparation or processing other than heating, of which the characteristic ingredient, apart from any filling, is ground cereal, whether or not flavoured, coated with or containing any carbohydrate sweetening matter, chocolate or cocoa; and includes shortbread, sponges, pastry, pastry cases, crumpets, muffins, macaroons, ratafias, meringues and petits fours, but does not include pharmaceutical products, bread, biscuits, canned puddings, Christmas puddings or any product containing a filling which has as an ingredient any meat or fish or any animal, vegetable or microbial material processed before or during the preparation of the product to resemble the texture of meat or fish;

“fruit spread” means the product obtained by processing fruit, fruit pulp or purée and carbohydrate sweetening matter, with or without the addition of other substances, to a suitable consistency by the application of heat and of which the total soluble solids content is less than 65 per cent;

“jam” includes fruit jelly prepared in the way in which jam is prepared, marmalade and jelly marmalade;

“processed cheese” means cheese which has been subjected to a process of melting or mixing with or without the addition of emulsifying salts.

“raw peeled potatoes” includes chips, sliced potatoes, diced potatoes and potatoes which have undergone the culinary process known as “blanching”;

“sauce” means a liquid, thickened or unthickened, frozen or otherwise, used as a garnish with food and having a colour and flavour derived essentially from ingredients other than meat, but does not include mustard, gravy sauce or any product having characteristics similar to gravy;

“sausage” and “sausage meat” means a mixture of any raw meat, cereals and condiments and includes hamburgers, lamburgers, beefburgers and similar products;

“soft cheese” means cheese which is readily deformed by moderate pressure but does not include whey cheese, processed cheese or cheese spread and any reference to soft cheese includes a reference to cream cheese or curd cheese;

“soft drink” means any non-alcoholic drink commonly known as a soft drink, whether capable or not of being used as a medicine;

“whey cheese” means the product obtained by (i) concentrating whey with or without the addition of milk and milk fat and moulding such concentrated whey, or (ii) coagulating whey with or without the addition of milk and milk fat.

SCHEDULE 2

PERMITTED PRESERVATIVE

PART I

PART II

SCHEDULE 3.

GENERAL PURITY CRITERIA

Unless otherwise provided in the specific criteria in Part II of this Schedule the preservatives referred to in Schedule 2 to these Regulations shall comply with the following criteria of purity:--

1. They must not contain more than 3 mg per kg of arsenic or more than 10 mg per kg of lead.

2. They must not contain more than 50 mg per kg of copper and zinc taken together, the zinc content however not to be higher than 25 mg per kg, subject to any exception deriving from the specific purity criteria in the European Communities (Preservatives in Food) (Purity Criteria) Regulations, 1981.

SCHEDULE 4

PART I

SAMPLING OF CITRUS FRUIT TREATED WITH DIPHENYL, ORTHO-PHENYLPHENOL AND SODIUM ORTHO-PHENYLPHENATE

I. Samples shall be taken using scientific methods which ensure that the samples are representative of the lot to be analysed.

II. The samples must satisfy at least the following requirements:

1. Packaged goods (crates, paperboard boxes, and similar containers).

2. Goods in bulk.

III. The lot shall be a part of a consignment which is characteristic of the consignment as to variety, degree of ripeness and type of packaging.

IV. The samples shall be placed in air-tight containers.

V. The containers shall be sealed.

VI. The samples thus packaged shall be delivered or consigned as quickly as possible to the approved examiner.

PART II

ANALYSIS OF CITRUS FRUIT TREATED WITH BIPHENYL, 2-HYDROXYBIPHENYL OR SODIUM BIPHENYL-2YL OXIDE

Qualitative analysis for residues of biphenyl, 2-hydroxybiphenyl and sodium biphenyl 2-yl oxide in citrus fruit

Purpose and scope

1. The method described below enables the presence of residues of biphenyl, 2-hydroxybiphenyl (orthophenyl-phenol) or sodium biphenyl-yl oxide (sodium orthophenyl-phenate) in the peel of citrus fruit to be detected. The sensitivity limit of this method, in absolute terms, is approximately 5 μg. for biphenyl and 1 μg. for 2-hydroxybiphenyl or sodium biphenyl 2-yl oxide, which is the equivalent of 5 mg. of biphenyl and 1 mg. of 2-hydroxybiphenyl respectively in the peel of 1 kg. of citrus fruit.

Principle

2. An extract is prepared from the peel using dichloromethane in an acid medium. The extract is concentrated and separated by thin layer chromatography using silica gel. The presence of biphenyl, 2-hydroxybiphenyl or sodium biphenyl-2yl oxide is shown by fluorescence and colour tests.

Reagents

3. The following reagents shall be used--

(a) cyclohexane (analytical reagent grade);

(b) dichloromethane (analytical reagent grade);

(c) hydrochloric acid 25 per centum (weight/volume);

(d) silica gel GF 254 (Merck or equivalent);

(e) 0.5 per centum (weight/volume) solution of 2,4,7-trinitrofluorenone (TNF) (Fluka, BDH or equivalent) in acetone;

(f) 0.1 per centum (weight/volume) solution of 2,6-dibromo-p-benzoquinonechlorimine in ethanol (stable for up to one week if kept in the refrigerator);

(g) concentrated solution of ammonia, specific gravity: 0.9;

(h) standard 1 per centum (weight/volume) solution of pure biphenyl in cyclohexane.

(i) standard 1 per centum (weight/volume) solution of pure 2-hydroxybiphenyl in cyclohexane.

Apparatus

4. The following apparatus shall be used--

(a) a mixer;

(b) a 250 ml. flask with ground glass joint and with a reflux condenser;

(c) a reduced pressure evaporator;

(d) micropipettes;

(e) a thin layer chromatographic apparatus with plates measuring 20 x 20 cm;

(f) an ultra-violet lamp (254 nm.), the intensity of which should be such that a spot of 5 ug. of biphenyl is visible;

(g) equipment for pulverising reagents;

(h) an oven.

Method of Analysis

5. The analysis shall be carried out as follows--

(a) Preparation and extraction: All the fruit in the sample for analysis is cut in half. Half of each piece of fruit is kept for quantitative determination of the residue of any biphenyl or 2-hydroxybiphenyl present. Pieces of peel are taken from the other halves to give a sample of about 80 g. These pieces are chopped, crushed in the mixer and placed in the 250 ml. flask; to this is added 1 ml. of 25 per centum hydrochloric acid and 100 ml. dichloromethane. The mixture is heated under reflux for 10 minutes. After cooling and rinsing of the condenser with about 5 ml. of dichloromethane, the mixture is filtered through a fluted filter. The solution is transferred to the evaporator and some anti-bumping granules are added. The solution is concentrated at reduced pressure at a temperature of 60°C. to a final volume of about 10ml. If a rotary evaporator is used, the flask should be kept in a fixed position to avoid loss of biphenyl through the formation of a film of the product on the upper wall of the flask.

(b) Chromatograpy: 30 g. of silica gel and 60 ml. of water are placed in a mixer and mixed for one minute. The mixture is then spread on to 5 chromatographic plates to form a layer approximately 0.25 mm. thick. The plates covered with this layer are subjected to a stream of hot air for 15 minutes and then placed in an oven where they are kept for 30 finutes at a temperature of 110°C.

After cooling, the surface layer of each plate is divided into lanes, 2 cm. wide, by parallel lines penetrating the silica gel down to the surface of the glass plate. 50 μl. of the extract to be analysed are applied to each lane as a narrow band of contiguous spots approximately 1.5 cm. from the lower edge of the plate. At least one lane is kept for the controls consisting of a spot of 1 μl. (that is, 10 μg.) of the standard solutions of biphenyl and 2-hydroxybiphenyl, one standard per lane. The chromatographic plates are developed in a mixture of cyclohexane and dichloromethane (25:95) in tanks previously lined with filter paper.

(c) Detection and identification: The presence of biphenyl and 2-hydroxybiphenyl is shown by the appearance of spots in ultra-violet light (254 nm). The sodium biphenyl-2yl oxide will have been converted to 2-hydroxybiphenyl during the extraction in an acid medium, and its presence cannot therefore be distinguished from that of 2-hydroxybiphenyl. The products are identified in the following manner--

(i) biphenyl gives a yellow spot in daylight when sprayed with the TNF solution;

(ii) 2-hydroxybiphenyl gives a blue spot when sprayed with the solution of 2, 6-dibromo-p-benzoquinechlorimine, followed by rapid passage through a stream of hot air and exposure to an ammonia-saturated atmosphere.

Quantitative analysis of the residues of biphenyl in citrus fruit

Purpose and scope

1. The method described below gives a quantitative analysis of the residues of biphenyl in whole citrus fruit. The accuracy of the method is ±10 per centum for a biphenyl content greater than 10 mg. per kg. of fruit.

Principle

2. After distillation in an acid medium and extraction by cyclohexane, the extract is subjected to thin layer chromatography on silica gel. The chromatogram is developed and the biphenyl is eluted and determined spectrophotometrically at 248 nm.

Reagents

3. The following reagents shall be used--

(a) concentrated sulphuric acid solution;

(b) silicone-based anti-foaming emulsion;

(c) cyclohexane (analytical reagent grade);

(d) rhexane (analytical reagent grade);

(e) ethanol (analytical reagent grade);

(f) anhydrous sodium sulphate;

(g) silica gel GF 254 (Merck or equivalent);

(h) standard 1 per centum (weight/volume) solution of pure biphenyl in cyclohexane: dilute with cyclohexane to obtain the following three solutions--

(i) 0.6 μg/μl;

(ii) 1 μg/μl;

(iii) 1.4 μg/μl.

Apparatus

4. The following apparatus shall be used--

(a) a 1 litre mixer;

(b) a 2 litre distillation flask with a modified Clevenger-type separator as shown in the diagram in Part III and a cooled reflux condenser;

(c) a 10 ml. graduated flask;

(d) 50 μl. micropipettes;

(e) a thin layer chromatographic apparatus with 20 x 20 cm. plates;

(f) an oven;

(g) a centrifuge with 15 ml. conical tubes;

(h) an ultra-violet spectrophotometer.

Method of Analysis

5. The analysis shall be carried out as follows--

(a) Preparation and extraction: All the fruit in the sample for analysis is cut in half. Half of each piece of fruit is kept for qualitative analysis for residues of biphenyl, 2-hydroxybiphenyl or sodium biphenyl-2yl oxide. The other halves are put all together and shredded in a mill or crushed until a homogeneous mixture is obtained. From this at least two sub-samples of 200 g. are taken for analysis in the following manner. Each sub-sample is placed in a mixer with 100 ml. of water and mixed at slow speed for several seconds. Water is added until the volume of the mixture reaches 3/4 of the capacity of the mixer, and the mixture is then mixed for 5 miutes at full speed. The resulting purée is transferred to the 2 litre distillation flask. The mixer is rinsed with water and the rinsings added to the contents of the flask. (The total quantity of water to be used in mixing and rinsing is 1 litre). To the mixture are added 2 ml. sulphuric acid. 1 ml. anti-foaming emulsion and several anti-bumping granules. The separator and reflux condenser are fitted on to the flask. Distilled water is poured into the separator until the water level is well past the lower arm of the lateral return tube, followed by 7 ml. cyclohexane. Distillation is carried out for about 2 hours. The lower aqueous layer in the separator is discarded and the upper layer is collected in the 10 ml. graduated flask. The separator is rinsed with about 1.5 ml. of cyclohexane and the rinsings, added to the contents of the flask, which are then brought up to up to volume with cyclohexane. Finally a little anhydrous sodium sulphate is added and the mixture is shaken.

(b) Chromatography: 30 g. of silica gel and 60 ml. of water are placed in a mixer and mixed for one minute. The mixture is then spread on to 5 chromatographic plates to form a layer approximately 0.25 mm. thick. The plates covered with this layer are subjected to a stream of hot air for 15 minutes and then placed in an oven where they are kept for 30 minutes at a temperature of 110°C. After cooling, the surface layer of each plate is divided into 4 lanes, 4.5 cm. wide, by parallel lines penetrating the silica gel down to the surface of the glass plate. 50 μl. of the extract to be analysed are applied to one lane of each plate as a narrow band of contiguous spots approximately 1.5 cm. from the lower edge of the plate. 50 μl. of the standard solutions (i) (ii) (iii), corresponding respectively to 30, 50, and 70 μg. levels of biphenyl are applied in the same way to the three remaining lanes, one solution to each lane.

If a large number of samples are being analysed at one time, standard solutions need not be applied to every plate. Reference may be made to a standard curve provided that this curve has been prepared from the average values obtained from 5 different plates to which the same standard solutions have been applied.

(c) Development of chromatograms and elution: The chromatograms are developed with hexane to a height of 17 cm. in tanks previously lined with filter paper. The plates are air dried. By illuminating the plates with ultra-violet light (254 nm.), the areas of silica gel containing biphenyl are located and marked off in rectangles of equal area.

The entire layer of silica gel within the areas thus marked off is immediately scraped from the plate with a spatula. The biphenyl is extracted by mixing the silica gel with 10 ml. of ethanol and shaking several times over a period of 10 minutes. The mixture is transferred to the centrifuge tubes and centrifuged for 5 minutes at 2,500 revolutions per minute.

A control sample of silica gel is taken by the same method using an area of the same size. If a series of analyses are made, this control area is taken from an unused lane of a plate and below the solvent front; if a single analysis is made the control sample is taken from an area below one of the positions at which the standard biphenyl is located.

(d) Spectrophotometric determination: The supernatant liquid is decanted into the spectrophotometer cells and the absorption determined at 248 nm. against a control extract from a chromatographic area free from biphenyl.

Calculation of results

6. A standard curve is drawn, plotting the biphenyl values of 30, 50 and 70 μg. against the corresponding absorptions, as determined on the spectrophotometer. This gives a straight line which passes through the origin. This graph allows the biphenyl content of the samples to be read directly in mg. per kg. from the absorption value of their extracts.

Quantitative analysis of the residues of 2-hydroxybiphenyl and sodium biphenyl-2-yl oxide in citrus fruit

Purpose and scope

1. The method described below enables a quantitative analysis of the residues of 2-hydroxybiphenyl and sodium biphenyl-2yl oxide in whole citrus fruit to be made. The method gives results which for a 2-hydroxybiphenyl or sodium biphenyl-yl oxide content of the order of 12 mg. per kg. are low by an average value of between 10 per centum and 20 per centum.

Principle

2. After distillation in an acid medium and extraction by di-isopentyl eteher, the extract is purified and treated with a solution of 4-aminophenazone. A red colour develops, the intensity of which is measured spectrophotometrically at 510 nm.

Reagents

3. The following reagents shall be used--

(a) 70 per centum (weight/weight) orthophosphoric acid;

(b) silicone-based anti-foaming emulsion;

(c) di-isopentyl ether (analytical reagent grade);

(d) purified cyclohexane: shake 3 times with a 4 per centum (weight/volume) solution of sodium hydroxide, wash 3 times with distilled water;

(e) 4 per centum (weight/volume) sodium hydroxide solution;

(f) buffer solution at pH 10.4: into a 2 litre graduated flask put 6.64 g. of boric acid, 8.00 g. of potassium chloride and 93.1 ml. of N sodium hydroxide solution; mix and bring up to calibration mark with distilled water;

(g) reagent I: dissolve 1.0 g. of 4-aminophenazone (4-amino-2, 3-dimethyl-1-phenyl-5-pyrazolone; 4-aminoantipyrin) in 100 ml. of distilled water;

(h) reagent II: dissolve 2.0 g. of potassium ferricyanide in 100 ml. of distilled water. Reagents I and II must be kept in brown glass flasks and are only stable for approximately 14 days;

(j) silica gel;

(k) standard solution: dissolve 10 mg. of pure 2-hydroxybiphenyl in 1 ml. of 0.1 N NaOH; dilute to 100 ml. with a 0.2 M sodium borate solution (1 ml. = 100 μg. 2-hydroxybiphenyl). For the standard curve, dilute 1 ml. to 10 ml. with the buffer solution.

Apparatus

4. The following apparatus shall be used--

(a) a shredding or crushing mill;

(b) a mixer;

(c) a 1 litre distillation flask with a modified Clevenger-type separator as shown in the diagram in Part III and a reflux condenser;

(d) an electricity controlled heating mantle;

(e) a 200 ml. separating funnel;

(f) graduated cylinders of 25 and 100 ml;

(g) graduated flasks of 25 and 100 ml;

(h) 1 to 10 ml. pipettes;

(j) 0.5 ml. graduated pipettes;

(k) a spectrophotometer with 4 or 5 cm. cells.

Method of Analysis

5. All the fruit in the sample for analysis is cut in half. Half of each piece of fruit is kept for qualitative analysis for residues of biphenyl, 2-hydroxybiphenyl or sodium biphenyl-2yl oxide. The other halves are put all together and shredded in a mill or crushed until a homogeneous mixture is obtained. From this at least two sub-samples of 250 g. are taken for analysis in the following manner--

Each sub-sample is placed in a mixer with 500 ml. of water and mixed until a very fine homogeneous mixture is obtained in which the oily cells are no longer perceptible. A sample of 150 to 300 g. of the purée is taken, depending on the presumed 2-hydroxybiphenyl content and placed in the 1 litre distillation flask with a quantity of water sufficient to dilute the mixture to 500 g. in the flask. After the addition of 10 ml. of 70 per centum orthophosphoric acid, several anti-bumping granules and 0.5 ml. of anti-foaming emulsion, the separator and the reflux condenser are fitted on to the flask. 10 ml. of di-isopentyl ether are placed in the separator and the flask is heated gently in the electrically controlled heating mantle until the mixture boils. Emulsion formation is minimised if the mixture is boiled gently for the first 10 to 20 minutes. The rate of heating is then gradually increased until the mixture boils steadily and one drop of water reaches the trapping solvent every 3 to 5 seconds. After distilling for 6 hours, the contents of the separator are poured into the 200 ml. separating funnel, and the separator and the condenser are rinsed with 60 ml. of cyclohexane and then with 60 ml. of water. The rinsings are added to the contents of the separating funnel. The mixture is shaken vigorously and when the phases have separated the aqueous phase is discarded.

To extract the 2-hydroxybiphenyl, the organic phase is shaken vigorously 5 times, each time for 3 minutes, with 10 ml. of 4 per centum sodium hydroxide. The alkaline solutions are combined, adjusted to pH 9-10 with orthophosphoric acid in the presence of phenolphthalein paper, and diluted to 100 ml. with distilled water. A pinch of silica gel is added in order to clarify the solution which will have a slightly cloudy appearance. The solution is then shaken and filtered through a dry, fine-grain filter. Since colouring is developed with the maximum of accuracy and precision using quantities of 2-hydroxybiphenyl of between 10 and 70 μg. an aliquot sample of between 0.5 and 10 ml. of solution is taken with a pipette, taking into account the quantities of 2-hydroxybiphenyl which might be expected to be found. The sample is placed in a 25 ml. graduated flask; to this are added 0.5 ml. of reagent I, 10 ml. of the buffer solution and then 0.5 ml. of reagent II. The mixture is made up to the calibration mark with the buffer solution and shaken vigorously.

After 5 minutes the absorption of the red colouring at 510 nm. is measured spectrophotometrically against a control containing no extract. The colour does not lose intensity within 30 minutes. Evaluation is made by reference to a standard curve drawn from determinations using the standard 2-hydroxybiphenyl solution under the same conditions.

Observations

2. For each analysis it is recommended that the spectrophotometric determination be made with two different volumes of the neutralised alkaline extract.

Untreated citrus fruit give by this method a “blank” reading of up to 0.5 mg. per kg. for oranges and 0.8 mg. per kg. for lemons.

PART III

Diagram of a Modified Clevenger-type Separator

Note: The dimensions in this diagram are given in millimetres.

SCHEDULE 5

1. The label to which sub-article (1) of article 15 relates shall have on it a statement that the food contains permitted preservative, followed by the specific or common name of the preservative or, if any, the serial number for each preservative present in the food, specified in column 1 or column 3 of Schedule 2 to these Regulations.

2. (a) The label to which article 16 relates shall have printed on it a statement of:

(i) the serial number, if any, and the name as described in Schedule 2 to these Regulations of each permitted preservative present;

(ii) the name, in the case of a mixture of substances, of the mixed product, and

(iii) the percentage of each permitted preservative present.

(b) Each such statement shall be headed or preceded by the words “for foodstuffs (limited use)”.

3. The label to which sub-article (5) of article 12 relates shall have printed on it the statement specified in paragraph 2 of this Schedule and, in addition, the words “not for retail sale”.

4. Any statement required by paragraphs 1 to 4 of this Schedule:

(i) shall be clear and legible;

(ii) shall be in a conspicuous position on the label which shall be marked on, or securely attached to, the container in such a manner that it will be readily discernible and easily read by an intending purchaser or consumer under normal conditions of purchase or use;

(iii) shall not be in any way hidden or obscured or reduced in conspicuousness by any other matter, whether picorial or not, appearing on the label.

5. The letters and figures in every word in any statement to which paragraph 5 above applies:

(i) shall be in characters of uniform colour and size (being in the case of a label to which article 15 relates not less than 1.5 millimetres in height for containers of which the greatest dimension does not exceed 12 centimetres, and not less than 3 millimetres in height for containers of which the greatest dimension exceeds 12 centimetres and being in all other cases not less than 1.5 millimetres in height) provided that the initial letter of any word may be taller than any other letter in the word;

(ii) shall appear on a contrasting ground, so however that where there is no ground other than such as is provided by a transparent container and the contents of that container are visible behind the letters, those contents shall be taken to be the ground for the purposes of this paragraph.

6. A container referred to in article 16 shall have on it the name and address of the person importing or the person selling the preservative packed in the container or, if the preservative is manufactured within the State, the name of the manufacturer of the preservative.

7. For the purposes of this Schedule:

(i) the height of any lower case letter shall be taken to be the height thereof, disregarding any ascender or descender thereof;

(ii) any requirement that letters or figures shall be of uniform height, colour or size shall be construed as being subject to the saver that any inconsiderable variation in height, colour or size, as the case may be, may be disregarded.

EXPLANATORY NOTE.

(This note is not part of the Regulations and does not purport to be a legal interpretation.)

These Regulations which come into operation on 1 October, 1981 control the use of preservatives in food by prohibiting the manufacture, preparation, importation, distribution or sale for use in food of any preservative other than a permitted preservative and any food which contains preservatives other than preservatives permitted by the Regulations.

The Regulations provide that food being manufactured, prepared, imported, distributed, or sold shall not contain preservatives, as defined, except as provided for in the Regulations, and prescribe the foods that may contain certain preservatives and the limit, if any, of such preservatives that may be contained in them. They provide that certain foods may contain a mixture of preservatives within certain limits. They prescribe labelling requirements for foods containing preservatives and for preservatives.

The Regulations provide that where a sample of food has been certified not to comply with the Regulations, an authorised officer may seize, remove and detain such food as being food which is unfit for human consumption and, in certain circumstances, destroy it.

The Health (Preservatives in Food) Regulations, 1973 ( S.I. No. 147 of 1973 ) are being revoked on 1 October, 1981.