Document dnaxeNGdOzE2vB4qDxjgM8wJB

UNITED STATES DEPARTMENT OF AGRICULTURE AGRICULTURAL RESEARCH ADMINISTRATION BUREAU OF ANIMAL INDUSTRY WASHINGTON 25, D. C. ADDRESS REPLY TO "CHIEF OF BUREAU OF ANIMAL. INDUSTRY'* AND REFER TO YLY'4.136.2 /n August 3, 1949 Dr. William E. McCormick Department of Industrial Hygiene and Toxicology The B. F. Goodrich Company Akron, Ohio In V V_/ Dear Dr. McCormick: This is in reply to your letter of June 23rd requesting approval of your plastic wrapping films 012212 and 012220G for contact with meat and meat food products. No objection will be made by this office to the use of .your films as wrappers for federally inspected meat and meat food products, provided the extractables are composed, as you state, of. monoglycerol oleate and acrawax. We would appreciate receiving a copy of the method used by your laboratory in determining that chlorine and nitrogen were absent in the material extracted by petroleum ether. Very truly yours R. M. Mehurin, Chief Laboratory Section Meat Inspection Division X V 20466001 BFG03566 August 23, 1910 Mr* R* II, Hshurln, Chief Laboratory Section Meat Inspection Division TTS* Depart--nt of Agriculture Washington, DC* Dear Ur, Hehuriat In reply to your request of August 3, 19b9 the following is a rest-- of the --thod which we used for determining the absence of both chloride and nitrogen In our plastlo wrapping fline 012212 and 01222001 the Petrols-- ether need far extracting the film should bee* a 30 60 Q boiling ranges Usee enall piece of sodium la gee test tube, being careful not te handle the toot tube with the fcanda* Malt and drop in wall pisee of the caaple, heat te rednesO, drop ia snothcr piece of the sample, heat te redness, eto* until no longer able to get "flash" of staple* Drop hot teat tube late large toot tube containing distilled water* (lhle should shatter*) Dissolve sample and filter* Acidify 2 oo of the filtrate with dilute 6 normal nitrio sold. Add a few drops of 5jC silver nitrate* A mite preoipitats of silver ohloride indicates shierids* To 5oe of the saaple add 3 drops sash of 10^ soditsa hydroxide solution, ferrous swoniun sulfate solution and 2Q?t potassins fluoride solution. Boil gently 30 seconds* Cool under tap. Add one drop ferric chloride (5% solution)* Acidify with dilute sulfurio aoid (6 normal - 50% distilled water end 50jC sulfuric sold) until ferrio hydroxide Just dissolves* Prussian blue Indicates nitrogen* Very truly yours. Um* B* McCormick Depart--nt of Industrial Hygiene and Toxicology mi vs BFG03567 20466002 Jfflao 2J, 1^1)9 Ur, E, U* Uehnrla, Chief laboratory Sootion Meat Inapoetion Division U*8. Eepartaant of Agriculture Washington, D*C* Dear Mr* Mebnrlnt It ooa agreed la oar loot oonferenoe on Itoreh 23, 19t|9 -with you ud Br* Lehman a group that we would attest to further characterise the nature of tho cactoaetablea of filae 012212 aad 0122200, aa presented la or report of February 2), 2Sti9 (tost with ay lottor of Marsh 1), 19li9K Baaploo of oath of thoM filaa have boon aztraetod with patrblaua/ otter at outlined la tte origin*! report, Those extracts wort then ahjotted to bote a ttaadard aodlaa ftulumUitr nitrate teit far ohlorido aad a ttaadard aodlaa faslsosFrnteliia Bln* teat for fclteogta. Tte teata waro nsgatise la bote oaaot. We believe tela deaonstrates quit* wall that tte extractable art oampoced Of aenoglyeerol olaato aad aerawax aa o^roaaod to yea In ear eonfOren**. Wo boliero wo hava demonstrated tte nontaxloity of sash of tteao filaa for food paolcaglng purposes. Wo, therefore, req^eet that they bo approved by your dopartaeat as wrappers for neat or neat product*. Tory truly yours. Wb. l. lieCormiok Departeoat of Iadaatrlal Qygieae ead Toxicology wgu s BFG03568 20466003 A STUDY OF THE SOLUBILITY PROPERTIES OF TWO CAST FILMS FOR FOOD PACKAGING PURPOSES Problem: BY THE B.F.GOODRICH COMPANY To study the solubility of two food wrapping films in both lard oil and dilute lactic acid (ph lj.,0) and to appraise them with respect to the potential extraction of harmful ingredients in food for which they may serve as a wrapper. Conclusions: The data obtained showed that - (1) The maximum solubility of the polymer in the films when immersed in lard oil or dilute lactic acid was of the order of 38 milligrams per pound of extractant, or about 82 parts per million. (2) The maximum hydrogen cyanide concentration resulting from immersion in either lard oil or dilute, lactic acid was no more then 0.25 p.p.m. This is equivalent to no more then about 0.1 milligrams per pound of food. (3) The maximum acrylonitrile content found with either lard oil or dilute lactic aoid extraction was 2*5 p.p.m., equivalent to about 1.3 milligrams per pound of food* The above figures represent ma-rimnm values which would obtain in practice only under the most adverse conditions* Introduction; The food wrappers in question are two semi transparent films manufactured by The B.F. Goodrich Company. They are designated as 012212 film and 012220G film. The extraction studies were designed in accordance with suggestions made by the Meat Inspection Division of The U.S. Department of Agriculture and ware intended to provide information relative to the solubility of each of the films in both lard oil and dilute lactic acid solution and to determine the presence of any free hydrogen cyanide and monomeric acrylonitrile in these media. A representative sample of each of the films is attached with this report. The extraction studies were performed by placing the film samples in intimate contact with the two media for thirty days at a temperature of 100 F. The determination of small amounts of soluble polymer in lard oil is a difficult 360099K)Z BFG03569 2- procedure. A turbidimetric method has been used by workers at Battalia Memorial Institute and while the technique has its merits, it determines the solubility only under a given set of conditions which may not apply in the present case. Qualitative usb of this technique has been applied in this problem, but a different approach has been used for quantitative determination of polymer solubility. It has been demonstrated that using chlorine or nitrogen atoms in the polymer as tracers is entirely impractical if not impossible unless the solubility is high. Since the solubility is definitely low, another technique was devised. Petroleum, ether is essentially a non-solvent for the polymer films and an excellent solvent for lard oil. It is postulated that if there is no solubility of the polymer itself in lard oil, there will be no difference between the percent loss in weight of a film sample immersed in lard oil and subsequently extracted with petroleum ether and that of another film sample extracted only with petroleum ether. The only case which would lead to erroneous results is the case where a portion of the polymer itself is at least as soluble in lard oil as in petroleum ether. To guard against a false conclusion under such conditions, some knowledge of the non-polymer ingredients and their solubilities must exist. The difference between the percentage of film ingredients known to be soluble in lard oil or petroleum ether and the total percentage extracted by lard oil and petroleum ether is a measure of the maximum possible polymer solubilityin the lard oil. A more probable value is the difference between the lard oil-petroleum ether extract and the petroleum ether extract alone. Even this value may give a value for polymer solubility which is too high because of solubility of a film ingredient in lard oil but not in petroleum ether. The procedure described below is based on the above postulates. The method of determination of free monomeric acrylonitrile used in this study again gives the maximum possible value since it is based on determination of total nitrogen compounds volatile from lard oil or water and soluble in sulfuric acid to form an amide or ammonium salts. Thus it could include volatile amines, etc. The method described for determination of free hydrogen cyanide has been reported BFG03570 20466005 3- - in the literature and "was modified to suit the needs of this study and tested with known mixtures. It has been found by experiment that approximately 3 grams of film will be used to wrap a pound package of oleomargarine or animal fat. In the conclusions as well as in the experimental data a value of 3 grams has been used as the weight of film needed per pound of fat. Procedures Preliminary experimentation revealed no heat loss when drying these films at 105 C. Consequently the films were tested without first drying them to constant weight. From a practical standpoint it was necessary to limit both the size of the film and the volume of immersion liquid while still maintaining essentially complete contact of the film with the liquid. Sinoe about 3 grams of the film are used per pound of oleomargarine or animal fat, this ratio was first considered. However, it was later decided, after a discussion with the Heat Inspection Division, to use about 1 gram of film in 50 to 100 ml. of solvent. This ratio worked satisfactorily when a glass stoppered 250 ml. flask was used as the container, although the unsupported film was rather difficult to manipulate. The following procedure was adopted for the immersion test: Weigh a film, about 3" x 8", dried to constant weight. Place this in a 250-300 ml. glass stoppered flask containing 75 ml. of lard oil or of lactic acid water solution of pH 1*. Work the sample around in the flask with a stirring rod until air bubbles are removed and maximum contact with the solvent is obtained, being especially sure that the sanple is completely immersed. Place flask in an oven set for 100 F and allow it to reach oven temperature. Stopper and seal well with Pyseal. There should also be a liquid seal between stopper and flask, but do not use grease. Feplace flask in oven for 30 days. Remove from oven and leave unopened until the analyses can be started. BFG03571 20466006 The lard oil used was Eimer and Amend, Lard Oil, White, but it was definitely yellow brown in color and contained some suspended matter which dissolved or melted at 100 F or at higher temperatures leaving a clear deep straw colored liquid. Six samples of the film were immersed in each solvent. At the completion of the immersion period the following analyses were made on the films and solutions: A. Method of Analysis for Monomeric Acrylonitrile Immediately upon opening the flask, pour 30 ml* of the solvent into the pear shaped flask which is connected to the condenser as shown in Figure I. This apparatus should be ready to operate before sampling. The two absorption tubes each contain 1 ml. of cone. B,S(^and the ground glass joints are wet with the acid. Other joints may be sealed with stopcock grease. Bubble a stream of tank nitrogen or hydrogen through the system at a rate of 75"100 ml. per minute for 1 hour while keeping the sample flask near 100 C by means of a water bath* At the end of this period, carefully wash the connecting tubes and the absorp tion tubes into a well steamed semi-mioro Kjeldahl flask (60 ml.) using not more than 30 ml. total washings. Attach this flask to the distillation apparatus shown at the left of the figure, add 7 ml. of bSf TfrOH through the stopcock and steam distill, slow ly at first, into the receiver containing 10 ml. of l$> boric acid and indicator, until 25 ml. have distilled. Lower the receiver and distill about 5 ml. more. Cool flask, if necessary, and titrate with 0.010 to 0.015 N HCl. The end point is determined by the most distinct color change observable, usually from neutral gray to pink. Run all blanks to the same end point color. The use of a micro buret has little advantage be cause it requires about 0.02 to 0.03 ml. to cause an observable change in color at the end point. For lard oil runs, run a blank lard oil sample through the entire procedure. For lactic acid water solutions, run a blank distillation only, containing 2 ml. of the same HgSOj^ as used for the run. The indicator is a mixture of 25 ml. of Q.1% Brom Creso Green in 907= alcohol with 5 ml. of 0,1% Methyl Red in 90?. alcohol. Use p-ij. drops. Dilution will change indicator color so a standard procedure must be adopted. BFG03572 20466007 5- - Calculations: Volatile N compound as acrylonitrile, parts per million (micrograms per ml.) -- (A-B) X N X 53,000 30 A = ml. HCl used for run B * ml. HCl used for blank N - normality of HCl Report only to nearest whole number for low values. B. Analysis for Hydrogen Cyanide Bie method used is essentially that described by Settler and Goldbaum, Anal, Chem., 19, 270 (*24-7) In this case the aeration tube is a 30 ml. test tube connected with an absorbing tube and finally to the flanged orifice for holding the test paper described in the above paper. The 10 mm. orifioe was used for this work Set up the apparatus as shown at the right in Figure I, putting about 0.5 ml* of 6n HgSpk in the absorption tube. Grease should be used on all glass joints. Place 10 ml. of solvent from a freshly opened flask in the test tube. If it is a water solution, add about 1 ml. of 6 N Hr>S0^ and rapidly attach the test tube to the system. It is lard oil, simply attach to the system. A very small amount of trichloracetio acid may be added to the lard oil but it does not appear to be necessary and appreciable quantities cause darkening of the test paper. Turn on suction very gently, place a water bath under the test tube and heat to near boiling. At this point with a water solution in the tube, turn on full water aspirator suction for 5 minutes. With lard 011 in the tube, continue a moderate flow of air for 5 minutes, then increase suction to full flow and allow it to run for 10 minutes. The pores of the test paper will clog and slow down the flow after 2-5 minutes in both cases. Toward the end of the time period heat the absorption tube and connecting tubes with a flame. Remove the test paper from the flanged holder and immerse it in l:j. HCl until it is completely wetted and for an additional minute. Wetting time is often 5~U minute Yfash for about 1 minute in distilled water and dry the paper by heating in air. Compar the intensity of color with standards made by the same process and kapt between glass BFG03573 80(fe9%0Z 6- - microscope slides. Estimate the hydrogen cyanide only to the nearest microgram. The concentration in the solution is then, micrograms found divided by 10, expressed in parts per million volumes of solvent. C. Analysis of Film for Extraction Loss. 1. Lard Oil Immersions. Remove film from flask, wash with petroleum ether, place it between filter papers, roll into shape to fit a Soxhlet extractor and extract with petroleum ether for ij.8 to 72 hours. A satisfactory extractor to use is one with a capacity of about 200 ml. of liquid, emptying every 12 minutes. A smaller extractor might cut the time required to reach constant weight. 2. Lactic Acid Solution Immersions: Remove the film, wash with distilled water and dry in 105 C oven for about 1 hour, or to constant weight. Calculate loss of weight based on original film weight. Cheeking of Analytical Procedures Prior to the establishment of the present method, analysis for acrylonitrile was attempted by polarographio examination of -sapors swept from the solution into methanol. The method was not sufficiently sensitive and vapors from the lard oil caused interference. It was then established that if acrylonitrile is dissolved in concentrated B^>S0^ or is caught in it by means of absorption tubes that the nitrogen can be quantitatively determined by distillation as ammonia from an alkaline solution. No catalyst or heating is necessary, but the acid must be concentrated and there is some indication that the time in contact with acid may be a factor. One hour is sufficient. Nesslerization of the distilled ammonia would appear to be a more sensitive test. However, vapors carried over from the lard oil are also carried over in the distillation and result in heavy turbidity in the Nessler's reagent. It was necessary then, to adopt the volumetric method as described. This method proved to be accurate within 10$ of the amount of acrylonitrile present with water solutions. With lard oil solutions, made by adding small quantities of a BFG03574 20466009 -7- standard lard oil solution of acrylonitrile to samples of lard oil, the recovery by the method described is within 10/a for over 100 micrograms of acrylonitrile and within 20fo for smaller quantities. The limit of estimation, however, is about 30 micrograms of acrylonitrile, which gives a titration of only about O.Ol* ml. greater than the blank. The reproducibility of. the blank is about 0.01 ml. It must be kept in mind that the method will also determine amines or other volatile nitrogen compounds which will yield ammonia during the distillation process. The hydrogen cyanide (HCN) method was calibrated with water solutions using the method as described in the literature. The ferrous-ferric caustic test papers were used as described and standard colors which were reproducible to about 0.5 micro grams were obtained for comparison. For HCN in lard oil, standard oil solutions were prepared by successive dilutions of a sodium cyanide solution with alcohol containing trichloraoetio acid and finally with lard oil. Only about 0.1 ml. of alcohol was present in the final test solution. It was found that from 2 to 5 micro grams of HCN gave test papers essentially as intense as the corresponding water solution- runs. However, because of a slight brown coloration always obtained from the lard oil, 1 microgram could not be detedted. 1 microgram is only just visible from a water solution. Therefore, a negative test has been considered to be less than 2 micrograms of ECN (0.2 p.p.m.) in lard oil. It is probable that the use of the smaller orifice described by Gettler and Goldbaun would increase the sensitivity of this test if the need arises. Composition of-Films: Each of the films contains as its base a mixture of a vinyl resin (either Geon 202 or vinylite VYDR) and Perbunan 35NS90 rubber. In addition to these two basic ingredients they contain minor quantities of, (a total of about 5%) mono glyceryl oleate edible A, acrowax, and santocell C. The difference in the two films, aside from minor variations in relative amounts of the basic ingredients, is that 012212 contains Geon 202 resin while 012220G contains vinylite VYDR resin, fie suits: The resrlts of the investigation are summarized in Table I* BFG03575 20466010 8- - TABLE I 012220G Film Immersion 30 days at 100 F., plus about 15 days at room temperature. Sample No. Pet. ether extract Pet. ether alone, % HCN p.p.m. Acrylonitrile pp.m 1 2 3 4 5 6 Avg. 2.94 3.10 2.98 Lost 2.90 3.08 3.00 2.97 3.03 3.06 3.02 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2 ^-0.2 <1 <1 <1 <1 <-1 <1 <1 012212 Film Immersion 30 days ^-t 100 F., plus about 30 days at room temperature. 1 4.25 4.18 <0.2 <1 2 4.20 4.26 20.2 <1 3 4.30 <0.2 1 4 4.30 <0.2 1 5 4.20 <0.2 <1 6 4.20 <0.2 <1 Avg. 4.25 4.22 2-0.2 <1.0 OJ2PPOG Film Immersion in dilute laotio aoid solution (ph 4*0) 30 days at 100 f., plug 20 days at room temperature* Sample No. Lactio aoid soluble % of film HCN, p.p.m. in solution Aorylonitrile, p.p.m. in solution 1 2 3 4 5 6 Avg. 0.54 0.56 0.54 0.70 0.64 0.64 0.60 0.1 0.1 ! 0.2 0.1 0.1 0.1 0.1 1 1 1 1 1 1 1 012212 Film 30 days immersion in dilute lactio acid (pH 40), plus about 30 days at room temperature 1 0.55 2 Lost 3 0.60 4 0.50 5 0.85 0.2 3 0.3 3 0.2 2 0.3 3 0.2 2 6 Avg. 0.65 O.63 0.3 0.25 2 2.5 BFG03576 8 9- - Immersions were for J>0 days at 100 F., plus varying periods at room temperature as indicated in the above table. Approximately one gram of the film was used in each of the tests. From an intimate knowledge of the film, composition the theoretical solubility of various ingredients of the film in lard oil, petroleum ether, and water can be determined. These values are given in the first 2 columns of tables 2 and 3* By comparing these values with the results found in Table 1 the conclusion expressed in the last 2 columns of tables 2 and 3 can he drawn. Table II Non-polymer portion sol. in lard oil plus pet, ether, % of film Minimum probable 2.1*5 2.75-3.0 3.0 3.5 -4.0 Lard Oil Solubility of Polymer Film Actual Sol., % of film Pet. Ether Sol., alone % of film 0122200 012212 3.0 4.25 3.0 4.20 Possible polymer, dissolved, % of film Maximum Probable 0.55 0 1.25 0.0-0.5 Table IU Lactic Acid Solution Solubility of Polymer Non-polymer water soluble, % of film ________ ______________ Film i mnVmum 0"** 0-1.3 Probable 0.3-0.6 0122206 0.5'1' 012212 Actual loss of Weight < of film 0.60 O.63 Possible polymer dissolved,# of film. Maximum Probable 0.60 0.63 0-0.3 0.1 The qualitative test for appreciable quantities of polymer soluble in lard oil used by Battelle Memorial Institute in a quantitative manner was tried on these samples of lard oil after the immersion period. Comparison of the blank lard oil with the lard oil from runs in 5 inch columns of liquid gave no indication of turbidity. Dilution 1:1 and 1:3 with petroleum ether followed by thorough mixing caused a slight turbidity but it was fully as great, to the eye, in the blank solution as in the ones in which film had been immersed. These tests indicate only, that there was no appreciable quantity of polymer suspended in the lard oil. The actual solubility under such conditions would be a function of the particular polymer. However, rather small quantities of polymer will normally precipitate or cause turbidity when the oil is silutad with hydrocarbons. 20466012 BFG03577 - 10 Summary; These data can be put in another form to demonstrate the effect of this solubility on any food product of a nature such as lard oil or aqueous lactic acid solution. If it is assumed that the % of soluble film polymer can be projected on the basis of the wrapping for a pound of oleomargarine or meat, then the films which weigh about 3 grams per oound of food would have a maximum polymer solubility of 17 parts per million (01220G Film) and 38 parts per million (012212 Film). They would probably have a maximum solubility of about 18 parts per million each, if the package is in contact with only lean meat, the liquid content of which would approximate dilute lactic acid solution. The figures on hydrogen cyanide and acrylonitrile indicate that under the worst possible conditions there could be no more than 0.25 parts per million of hydrogen cyanide or 1 part per million of acrylonitrile present per pound of food. February 2I4., 19U9* BFG03578 20466013 20466014 BFG03579  ,AV. ^ m m\****Cit&*r^ dPt.v&'qte&'K'Z&&*>**-i&tW v^ jfeWjSft^wnw^iji** v*.>*r . s' V- * Ft \-rti oiaiaoe ,..V'i 20466015 t BFG03580 BFG03581 20466016 <