S.I. No. 147/1973:

HEALTH (PRESERVATIVES IN FOOD) REGULATIONS, 1973.

HEALTH (PRESERVATIVES IN FOOD) REGULATIONS, 1973.

The Minister for Health in exercise of the powers conferred on him by sections 5 , 54 , 58 and 59 of the Health Act, 1947 (No. 28 of 1947), subsection (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 Commerce and the Minister for Agriculture and Fisheries hereby makes the following Regulations:--

PART I. Preliminary and General

1. These Regulations may be cited as the Health (Preservatives in Food) Regulations, 1973.

2. These Regulations shall come into operation on the first day of July, 1974.

3. (1) The Health (Preservatives in Food) Regulations, 1972 ( S.I. No. 43 of 1972 ) and the Health (Preservatives in Food) (Amendment) Regulations, 1972 ( S.I. No. 302 of 1972 ) 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--

"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 Health Act, 1947 ;

"authorised officer" means an authorised officer for the purpose of Part IX of the Health Act, 1947 ;

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

"food" does not include preservatives;

"permitted preservative" means any preservative described in the Second Schedule to these Regulations which complies with any specific purity criteria in relation to that preservative specified in Part II of the Third Schedule to these Regulations and (so far as is not otherwise provided by any such specific purity criteria) with the general purity criteria contained in Part I of that Schedule;

"pre-packed" means made up in a container for the purpose of retail sale prior to exposure or offer for sale;

"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 Health Act, 1947 ;

(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 substances added to food by smoking;

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

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

"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 impregnated, coloured, gummed, painted or otherwise treated in a similar manner:

"specified food" means any food of a description specified in the first column of the First Schedule to these Regulations;

(2) Reference in these Regulations to percentages and parts per million shall be construed as reference to percentages and parts per million calculated by weight.

(3) 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. Any reference in these Regulations to an owner or to a person in apparent charge or control of 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.

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

7. There Regulations shall be enforced and executed by health boards in their functional areas.

8. (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 in apparent charge or control of 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 in apparent charge or control of 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.

(6) In this article "food" includes preservatives.

PART II. Sale, etc. of Preservatives and of Food Containing Preservatives

9. Subject to the provisions of these Regulations a person shall not import, distribute, sell or expose for sale--

(a) any preservative, other than a permitted preservative, for use in the manufacture or preparation of food;

(b) any permitted preservative in such a manner as to be likely to lead to its use contrary to these Regulations.

10. Subject to the provisions of these Regulations a person shall not import, distribute, sell or expose for sale any food which contains any preservative not naturally present in the food other than a permitted preservative described in Part II of the Second Schedule to these Regulations.

11. (1) Any specified food may contain an amount not exceeding that specified in the third column of the First Schedule to these Regulations of a preservative described in the second column of the said Schedule in relation to such food.

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

(3) (a) Any food which contains any specified food (other than fruit and fruit pulp intended for manufacturing purposes and any unfermented grape juice product intended for sacramental use) may, subject to paragraph (b) of this sub-article, contain an amount of the preservatives not exceeding that permitted by these Regulations for such specified food.

(b) If a specified food may under these Regulations contain sulphur dioxide, any food containing two or more ingredients, any of which is such specified food, may contain an amount of sulphur dioxide not exceeding the amount permitted under paragraph (a) of this sub-article, or fifty parts per million, whichever is the greater.

(4) A preservative described in the second column of the Second Schedule to these Regulations may be used instead of the preservative described in relation thereto in the first column of that Schedule and where any such preservative is so used the amount used shall not exceed that specified for the preservative for which it is substituted in the third column of the First Schedule and any reference in these Regulations to any preservative described in the first column of the Second Schedule shall be construed accordingly.

(5) Any specified food and any food (other than fruit and fruit pulp intended for manufacturing purposes containing sulphur dioxide and any pre-packed food) which is intended for use in the preparation of a specified food and which is imported or sold otherwise than by retail for that purpose may contain an amount exceeding that specified in the third column of the First Schedule to these Regulations of a preservative described in the second column of the said Schedule in relation to such specified food if it is packed in a container bearing a label which complies with the requirements for such a label specified in the Fifth Schedule to the Regulations.

12. (1) Notwithstanding sub-article (1) of Article 11 of these Regulations the permitted preservatives described in the Second Schedule 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 the first column of the First Schedule to these Regulations in relation to such preservatives.

(2) A person shall not import, distribute, sell or expose for sale 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 a sale by retail, pre-packed, there appears on a label attached to or borne on the container of the food or, in the case of a sale, other than pre-packed, by retail there appears on a ticket displayed on or in immediate proximity to the food, the words "Treated with preservative", provided that the common or usual name or description of the permitted preservative may be substituted for the word "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 diphenyl", "Treated with ortho-phenylphenol", "Treated with ortho-phenylphenate" or "Treated with thiabendazole", as appropriate.

13. (1) An authorised officer shall comply with the requirements specified in Part I of the Fourth Schedule 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 diphenyl, orthophenylphenol and sodium orthophenylphenate on citrus fruit in accordance with the methods of analysis specified in Part II of the Fourth Schedule to these Regulations.

PART III. Labelling and Advertising

14. (1) Subject to the provisions of these Regulations a person shall not import, distribute, sell or expose for sale 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 12) which contains any permitted preservative described in Part I of the Second Schedule 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 the Fifth Schedule to these Regulations or in the case of a retail sale of food which is not pre-packed 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 the First Schedule 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 sale in the course of a catering business of any specified food for immediate consumption, or

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

15. A person shall not import, distribute, sell or expose for sale 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 the Fifth Schedule to these Regulations.

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

(a) any preservative for use in food other than a preservative which is a permitted preservative in respect of such food,

(b) any permitted preservative 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.

FIRST SCHEDULE.

In this Schedule--

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

"flavouring emulsion" means an emulsion of a flavouring in a suitable liquid;

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

"flour confectionery" includes brack, cake, pastry whether cooked or uncooked, and ready-made puddings other than canned puddings and Christmas puddings but does not include biscuits or any product containing a filling that has as an ingredient any meat or fish;

"raw peeled potatoes" includes chips, sliced potatoes, diced potatoes and potatoes which have been blanched;

"sausage" and "sausage meat" mean a mixture of any raw meat, cereals and condiments and include hamburgers, lamburgers, beefburgers and similar products;

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

SECOND SCHEDULE.

PERMITTED PRESERVATIVES.

PART I.

PART II.

THIRD SCHEDULE.

PART I.

GENERAL PURITY CRITERIA.

Unless otherwise provided in the specific criteria in Part II of this Schedule the preservatives referred to in the Second Schedule 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.

3. They must not contain any measurable trace of other toxic elements, in particular other heavy metals.

PART II.

SPECIFIC PURITY CRITERIA.

General observations:

(a) Save as otherwise stated, quantities and percentages are calculated by weight on the anhydrous product.

(b) Where the relevant product is not anhydrous at the outset and the question of "volatile substances" arises, water is included among these substances.

(c) Where the drying period is not specified, this is to be taken as meaning "dried till constant weight".

Footnotes:

(¹) Cobalt chloride TSC Dissolve approximately 65 g of cobalt chloride CoC1 PT:7>₂ 6H ₂O in a sufficient quantity of a mixture of 25 ml hydrochloric acid and 975 ml water to give a total volume of 1 litre. Place exactly 5 ml of this solution in a round-bottomed flask containing 250 ml of iodine solution, add 5 ml of 3% hydrogen peroxide, then 15 ml of a 20% solution of sodium hydroxide. Boil for 10 minutes, allow to cool, add 2 g of potassium iodide and 20 ml of 25% sulphuric acid. After the precipitate is completely dissolved, titrate the liberated iodine with sodium thiosulphate (0·1 N) in the presence of starch TS(*). 1 ml sodium thiosulphate (0·1 N) corresponds to 23·80 mg of CoCl₂·6H₂O. Adjust final volume of solution by the addition of a sufficient quantity of the hydrochloric acid/water mixture to give a solution containing 59·5 mg of CoCL₂·6H₂O per ml.

(²) Ferric chloride TSC Dissolve approximately 55 g of ferric chloride in a sufficient quantity of a mixture of 25 ml hydrochloric acid and 975 ml water to give a total volume of 1 litre. Place 10 ml of this solution in a round-bottomed flask containing 250 ml of iodine solution, add 15 ml of water and 3 g of potassium iodide; leave the mixture to stand for 15 minutes. Dilute with 100 ml water then titrate the liberated iodine with sodium thiosulphate (0·1 N) in the presence of starch TS*. 1 ml of sodium thiosulphate (0·1 N) corresponds to 27·03 mg of FeC1₃·6H₂O. Adjust final volume of solution by the addition of a sufficient quantity of the hydrochloric acid/water mixture to give a solution containing 56·0 mg of FeCl ₃ 6H₂O per ml.

(³) Copper sulphate TSC. Dissolve approximately 65 g of copper sulphate CuS04·5H₂O in a sufficient quantity of a mixture of 25 ml hydrochloric acid and 975 ml water to give a total volume of 1 litre. Place 10 ml of this solution in a round-bottomed flask containing 250 ml of iodine solution, add 40 ml of water, 4 ml of acetic acid and 3 g of potassium iodide. Titrate the liberated iodine with sodium thiosulphate (0·1 N) in the presence of starch TS*. 1 ml of sodium thiosulphate (0·1 N) corresponds to 24·97 mg of CuS0·5H₂O. Adjust final volume of solution by the addition of a sufficient quantity of the hydrocloric acid/water mixture to give a solution containing 62·4 mg of CuSO₄·5H₂O per ml.

* Starch TS. Titrate 0·5 g starch (Potato starch, maize starch or soluble starch) with 5 ml of water; to the resulting paste add a sufficient quantity of water to give a total volume of 100 ml, stirring all the time. Boil for a few minutes, allow to cool, filter. The starch TS must be freshly prepared.

(⁴) The specification refers to glacial acetic acid (crystallisable); for aqueous solutions, calculate values corresponding to their glacial acetic acid content.

(⁵) May contain a slight excess of acetic acid or sodium acetate.

(⁶) The specification refers to an 80-85% aqueous solution; for weaker aqueous solutions, calculate values corresponding to their lactic acid content.

(⁷) The specification refers to anhydrous propionic acid; for aqueous solutions, calculate values corresponding to their propionic acid content.

FOURTH SCHEDULE.

PART I.

SAMPLING OF CITRUS FRUIT TREATED WITH DIPHENYL, ORTHOPHENYLPHENOL 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.

METHOD OF QUALITATIVE ANALYSIS FOR BIPHENYL, ORTHOPHENYLPHENOL AND SODIUM ORTHOPHENYLPHENATE IN CITRUS FRUIT PEEL

1. Object and field of application.

From the method described below conclusions as to the presence of biphenyl, orthophenylphenol (OPP) or sodium orthophenylphenate in the peel of citrus fruit can be reached. The sensitivity limit of this method, in absolute value, is approximately 5 micro grammes for biphenyl and 1 micro gramme for OPP or sodium orthophenylphenate, which equals 5 mg of biphenyl (5 ppm) and 1 mg of OPP (1 ppm) respectively in the peel of 1 kg of citrus fruit.

Treatment of citrus fruit with the above-mentioned products generally leads to the presence of residues in the peel of the fruit. Determination of these residues in the whole fruit therefore would seem to be necessary only in cases where they are found to be present in the peel.

2. Principle.

An extract is prepared from the peel using dichloromethane in an acid medium. The extract is concentrated and chromatographed in a thin layer on a column of silica gel. The presence of biphenyl, orthophenylphenol or sodium orthophenylphenate is shown by fluorescence and changes in colour.

3. Reagents.

cyclohexane (Analak)

dichloromethane (Analak)

hydrochloric acid 25% w/v

silica gel GF 254 Merck or equivalent

acetone solution of 2, 4, 7 trinitrofluorenone (Fluka, B.D.H. or equivalent) at 0·5% (TNF)

ethanol solution of 2, 6-dibromo-benzoquinone-4-chloroimide at 0·1% (stable for one week if kept in the refrigerator)

concentrated solution of ammonia, d: 0·9

standard 1% solution of pure biphenyl in cyclohexane

standard 1% solution of pure orthophenylphenol in cyclohexane.

4. Equipment.

Mixer

250 ml flask with ground glass joint and refrigerated reflux condenser

Evaporator for evaporation at reduced pressure

Micropipettes

Chromatographic apparatus for thin layer plate chromatography 20 X 20 cm U.V. lamp (254 nm): the intensity should be such that a stain of 5 micro grammes of biphenyl is perceptible

Equipment for pulverising reagents

5. Method.

(a) Preparation of the sample and extraction.

All the fruit in the sample for checking is cut in half and half of each piece of fruit kept for quantitative determination of residues of biphenyl and/or orthophenylphenol. Pieces of peel are taken from the other halves to make a sample of about 80 g. These pieces are cut small, crushed in the mixer and placed in the 250 ml flask; to this is added 1 ml of 25% hydrochloric acid and 100 ml of dichloromethane. The mixture is heated under reflux for 10 minutes. After cooling and rinsing of the refrigerated reflux condenser with about 5 ml of dichloromethane, the mixture is filtered through a fluted filter. The solution is transferred to the evaporator and some porous stones are added. The solution is concentrated at reduced pressure at a temperature of 60°C to a final volume of about 10 ml. If a rotating 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) 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 poured on to 5 chromatographic plates and spread to form a layer approximately 0·250 mm in thickness. The plates covered with this layer are subjected for 15 minutes to a stream of hot air and then placed in an oven where they are kept for 30 minutes at a temperature of 110°C.

After cooling each plate is divided into strips 2 cm wide, by parallel lines penetrating the covering layer down to the surface of the plate. A few drops (50 micro litres) of the extract to be analysed are put close together on to each strip, approximately 1·5 cm from the edge. At least one strip is kept for the control solutions, consisting of a deposit of 1 micro litre (that is, 10 micro grammes) of standard solutions of biphenyl and orthophenylphenol.

The chromatographic plates are developed in a mixture of cyclohexane and dichloromethane (25:95) in dishes which have been previously lined with filter paper.

(c) Detection and Identification.

The presence of biphenyl and orthophenylphenol is demonstrated by the appearance of stains in U.V. light (254 nm). The sodium orthophenylphenate has changed into orthophenylphenol during the extraction in an acid medium, and its presence cannot therefore be differentiated from that of orthophenylpheno, The products are identified in the following manner:

(i) biphenyl has a yellow colouring in daylight when atomized with the TNF solution;

(ii) orthophenylphenol has a blue colouring when atomized with the solution of 2·6-dibromo-benzoquinone-4-chlorimide, passed rapidly through a stream of hot air and exposed to an ammonia-saturated atmosphere.

METHOD OF QUANTITATIVE ANALYSIS OF THE RESIDUES OF BIPHENYL IN CITRUS FRUIT.

1. Object and field of application.

The method described below gives a quantitative analysis of the residues of biphenyl in citrus fruit (whole fruit). The accuracy of the method is+10% for a biphenyl content greater than 10 mg per kg of fruit (10 ppm).

2. Principle.

After distillation in an acid medium and extraction by cyclohexane, the extract is chromatographed in a thin layer on silica gel. The chromatogram is developed and the biphenyl is eluted and determined spectrophotometrically at 248 mm.

3. Reagents.

Concentrated sulphuric acid solution

Silicone-based anti-frothing solution

cyclohexane p.a.

hexane p.a.

ethanol p.a.

anhydrous sodium sulphate

silica gel GF 254 Merck or equivalent

standard 1% solution of pure biphenyl in cyclohexane: dilute with cyclohexane to obtain the following three solutions:

(a) 0·6 micro grammes/micro litres; (b) 1 micro gramme/micro litre; (c) 1·4 micro grammes/micro litres.

4. Equipment.

1 1 mixer

2 1 distillation flask with modified Clevenger-type separator* and refrigerated reflux condenser

10 ml graduated flask

50 micro litres micropipettes

thin layer chromatographic equipment with 20 X 20 cm plates oven

centrifuge with 15 ml conical tubes

U.V. spectrophotometer

5. Method.

(a) Preparation of the sample and extraction.

All the fruit in the sample for checking is cut in half and half of each piece of fruit kept for qualitative analysis for residues of biphenyl, OPP or sodium orthophenylphenate. The other halves are put all together in a mill and shredded 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 ¾ of the contents of the mixer, and the mixture is then mixed for 5 minutes at full speed. The resulting purée is transferred to the 2 L distilling 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 the mixing and rinsing is 1 L). To the mixture are added 2 ml sulphuric acid, 1 ml antifrothing emulsion and several porous stones. The separator and reflux condenser

CLEVENGER

are fitted on to the flask. Into the separator is poured distilled water, until the water level is well past the lower arm of the lateral return tube, followed by 7 ml of cyclohexane. This is distilled for about 2 hours. The contents of the separator are then 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 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 poured on to 5 chromatographic plates and spread to form a layer approximately 0·250 mm in thickness. The plates covered with this layer are subjected for 15 minutes to a stream of hot air and then placed in an oven where they are kept for 30 minutes at a temperature of 110°C. After cooling each plate is divided into 4 strips 4·5 cm wide, by parallel lines penetrating the covering layer down to the surface of the plate. A few drops (50 micro litres) of the extract to be analysed are put close together on to one of the strips approximately 1·5 cm from the edge of the plate. On to each of the three other strips are put in the same way 50 micro litres of the standard solutions (a), (b) and (c), corresponding respectively to a biphenyl residue of 30, 50 and 70 micro grammes.

If the analyses are proceeded with in series, the putting of standard solutions on to each plate may be omitted and the standard curve may be deduced from the average of the values obtained from at least five plates, with the same standard amounts.

(c) Development of chromatograms and elution.

The chromatograms are developed with hexane to a height of 17 cm in dishes previously lined with filter paper. The plates are dried in the open air. The zones in which the biphenyl is localised are picked out in U.V. light (254 nm), and marked off in rectangles of equal area.

These marked-off areas are immediately scraped clean with a spatula, right through the thickness of the supporting layer. The biphenyl is extracted by means of 10 ml of ethanol, for 10 minutes, shaking several times. The mixture is transferred to the centrifuge tubes and centrifuged for 5 minutes at 2,500 r.p.m.

A sample control area of the same size is taken by the same method. If the analyses are in series, this control area is taken from an unused strip of the plate; if the analyses are done individually, it is taken from one of the strips containing a standard located below the zone containing the biphenyl.

(d) Spectrophotometric determination.

The free liquid is decanted into the spectrophotometer cells and the extinction determined at 248 nm and compared with a control extract from a chromatographic zone free from biphenyl.

6. Results.

A standard curve is drawn, plotting the biphenyl values of the 30, 50 and 70 micro grammes against the corresponding extinctions, 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 ppm from the extinction value of their extracts.

METHOD OF QUANTITATIVE ANALYSIS OF THE RESIDUES OF ORTHOPHENYLPHENOL AND SODIUM ORTHOPHENYLPHENATE IN CITRUS FRUIT PEEL.

1. Object and field of application.

The method described below gives a quantitative analysis of the residues of orthophenylphenol (OPP) and sodium orthophenylphenate in citrus fruit (whole fruit). The method gives results which for an OPP or sodium orthophenylphenate content of the order of 12 ppm are low by an average value of between 10 and 20%.

2. Principle.

After distillation in an acid medium and extraction by di-isopentyl ether, the extract is purified and treated with a solution of l-phenyl-2·3-dimethyl-4-aminopyrazolone (5) (=4-aminoantipyrine). A red colouring develops the intensity of which is measured by spectrophotometry at 510 nm.

3. Reagents.

70% phosphoric acid

silicone-based anti-frothing emulsion

di-isopentyl ether (Analak)

purified cyclohexane; shake 3 times with a 4% solution of sodium hydroxide, wash 3 times with distilled water

4% sodium hydroxide solution

buffer solution at pH 10·4: into a 2 1 graduated flask put 6·64 g of boric acid, 8·00 g of potassium chloride and 93·1 ml of 1 N sodium hydroxide solution; mix and bring up to calibration mark with distilled water

reagent I: dissolve 1.0 g of l-phenyl-2·3-dimethyl-4 ammopyrazolone (5) (=4-amino-antipyrin) in 100 ml of distilled water

reagent II: dissolve 2·0 g of potassium ferrocyanide in 100 ml of distilled water. Reagents I and II must be kept in brown glass flasks and are no longer stable after approximately 14 days

silica gel

standard solution: dissolve 10 mg of pure OPP in 1 ml of NaOH 0·1 N; dilute to 100 ml with a 0·2 sodium borate solution (1 ml = 100 micro-grammes). For the standard solution, dilute at 1:10 with the buffer solution.

4. Equipment.

shredding or crushing mill mixer

1 1 distilling flask with modified Clevenger-type separator† and reflux condenser

infra-red bath

200 ml separatory funnel

graduated cylinders of 25 and 100 ml

graduated flasks of 25 and 100 ml

1 to 10 ml pipettes

0·5 ml graduated pipettes

spectrophotometer with 5 cm cells

5. Method.

All the fruit in the sample for checking is cut in half and half of each piece of fruit kept for qualitative analysis for residues of biphenyl, OPP or sodium orthophenylphenate. The other halves are put altogether in a mill and shredded 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, according to the presumed OPP content, and placed in the 1 1 distilling 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% phosphoric acid, several porous stones and 0·5 ml of anti-frothing emulsion, the separator and the reflux condenser are fitted on to the flask. 10 ml of di-isopentyl ether is put into the separator and the flask is heated gently in the infra-red bath, without allowing the puree to cook or froth to form. After distilling for 6 hours, the contents of the separator are poured into the 200 ml separating flask, 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 eliminated.

To extract the OPP, the organic phase is shaken vigorously five times, each time for three minutes, with 10 ml of 4% sodium hydroxide. The alkaline solutions are collected, neutralized to pH 9-10 with phosphoric acid in 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 the colouring is developed with the maximum of accuracy and precision, using quantities of OPP of between 10 and 70 micro grammes, an aliquot sample of between 0·5 and 10 ml of solution is taken with a pipette, taking into account the quantities of OPP 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 brought up to the calibration mark with the buffer solution and shaken hard.

After 5 minutes the extinction of the red colouring at 510 nm is measured with the spectrophotometer, in comparison with a control containing no extract. The colour does not lose intensity within 30 minutes. The evaluation is made using the standard curve drawn in the same conditions with the standard OPP solution.

6. Observations.

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

Non-treated citrus fruit give by this method a reading of up to 0·5 ppm for oranges and 0·8 ppm for lemons.

†See figure on Page 30.

FIFTH SCHEDULE.

1. The label to which sub-article (1) of article 14 relates shall have printed on it a statement in one of the following forms or in a form substantially to the like effect:--

CONTAINS PRESERVATIVE.

or

CONTAINS PERMITTED PRESERVATIVE.

In the case of any unfermented grape juice product intended for sacramental use to which these Regulations apply, the words "and is not intended for use as a beverage" shall be added.

2. The label to which article 15 relates shall have printed on it a true statement of:

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

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

(c) the percentage of each permitted preservative present.

3. Each such statement shall be headed or preceded by the words "for foodstuffs (limited use)".

4. The label to which sub-article (6) of article 11 relates shall have printed on it the statement specified in paragraphs 2 and 3 of this Schedule and, in addition, the words "not for retail sale".

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

(a) shall be clear and legible;

(b) 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;

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

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

(a) 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;

(b) 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.

7. A container referred to in Article 15 shall have on it the name and address of the person importing or the person selling or exposing for sale the preservative packed in the container or, if the preservative is manufactured within the State, the name of the manufacturer of the preservative.

8. For the purposes of this Schedule:

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

(b) 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.

GIVEN under the Official Seal of the Minister for Health this 11th day of June, 1973.

BRENDAN CORISH,

Minister for Health.

EXPLANATORY NOTE

These Regulations which come into operation on 1st July, 1974 prohibit the importation, distribution, sale or exposure for sale for use in food of any preservative other than a permitted preservative or any permitted preservative in such a manner as to be likely to lead to its use contrary to the Regulations.

The Regulations also provide that food being imported, distributed, sold or exposed for sale 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, 1972 ( S.I. No. 43 of 1972 ) and the Health (Preservatives in Food) (Amendment) Regulations, 1972 ( S.I. No. 302 of 1972 ) are being revoked on 1st July, 1974.