Historic, archived document Do not assume content reflects current scientific knowledge, policies, or practices. se*s e*actere*s UNITED STATES DEPARTMENT OF AGRICULTURE DEPARTMENT BULLETIN No. 1149 Washington, D. C. Vv May 9, 1923 ABSORPTION AND RETENTION OF HYDROCYANIC ACID BY FUMIGATED FOOD PRODUCTS. By E. L. Grirrin, Assistant Chemist, and I. E. Nrtrert, Junior Chemist, Insecticide and Fungicide Laboratory, Miscellaneous Division, Bureau of Chemistry; N. PERRINE, Assistant in Plant Fumigation, Federal Horticultural Board, and A. B. Ducxerr,! Scientific Assistant, Stored-Product Insect Investigations, Bureau of Entomology.” CONTENTS. Page. Page. JUN SUPE ae) = Beem Ss ean ee SA ners i ee 1-| Experimental wowket3 {005 soe ee: Foes Movie, Of HLerAlING sc<. 2.2 sk cane be cece eso 27 OUI AY cee re altel elas oo 2 te wie a eee 15 Purpose of investigation......................- A Bibliography ts 2045 S53 ba Se A Be ee 16 INTRODUCTION. Hydrocyanic acid, in the gaseous form, is used extensively in the United States as a fumigant for the destruction of insects and rodents, particularly the brown rat (Mus norvegicus). Probably the earliest recorded use of this gas for killing insects* was that by J. T. Bell (4),* who in 1877 employed it to nid an insect cabinet of insect pests. Credit is given to Dr. D. W. Coquillet for beig the first to suggest the use of hydrocyanic acid gas for destroying insects on plants. In 1886, while employed asjan agent of the United States Depart- ment of Agricuiture, he began experiments with it which later showed ‘6 Pits for the destruction of scale insects infesting citrus trees 14, 24). : Since 1886 the use of hydrocyanic acid gas as a fumigant has been extended greatly, until it now includes the fumigation of dwellings, barracks, etc. (12), for the destruction of certain insects which are ordinarily classed as vermin, such as roaches, water bugs, and bed- bugs, and the fumigation of warehouses and mills (7, 8) against certain insects that destroy food products. More recently this gas 1 Deceased. 3H. L. Sanford assisted in the fumigation work and J. J. T. Graham assisted in making the analyses of the stored grains. As the plants and plant products coming in at the various ports of entry from foreign countries frequently are infested with insects new to the United States, E. R. Sasscer, entomologist in charge of the Plant Quarantine Service of the Federal Horticultural Board, outlined the fumigation procedure upon which the investigations herein reported were based, with the idea of determining whether or not various fruits, vegetables, and stored products fumigated with hydrocyanic acid gas in concentrations lethal to insects would be poisonous to consumers. ON: * Reference is made to the use of hydrocyanic acid gas generated rapidly by the action of sulphuric acid on potassium amide or sodium cyanide, and not to the use of potassium cyanide for killing insects in collectors’ bottles, which probably is much the older practice. # The numbers (italics) in parentheses throughout this bulletin refer to the bibliography on page 16. 29302—23—Bull. 1149-———1 2 BULLETIN 1149, U. S. DEPARTMENT OF AGRICULTURE. has been employed at ports of entry (9, 17) to prevent the intro- duction from foreign countries of many injurious insect pests that have not yet gained a foothold here. Among the most important of these pests are the pink boll worm and the citrus black fly... _Fumi- gation with hydrocyanic acid gas is also a means for the prevention of epidemics of yellow fever (5) and bubonic plague (6, 13, 19). Ships coming from ports where these diseases exist are fumigated on arrival in order to kill mosquitoes and rats which carry the causative organisms. Food products fumigated to destroy the imsects with which they are infested come into contact with hydrocyanic acid. This is true in the fumigation of imported fruits and vegetables at ports of entry and in the fumigation of flour and grains in mills and warehouses. In destroying insects and rats in dwellings and ships, foodstuffs may not be removed during exposure to the gas. In any case there is the possibility of exposure to the fumigant of products intended for food. Since hydrocyanic acid is extremely poisonous to man, it is impor- tant to know how much of it is absorbed and retained byfoods. Very little work on this subject seems to have been done, although appar- ently the opinion that there is no danger in the fumigation of dry foods? is fairly general. REVIEW OF LITERATURE. Guthrie (10) was unable to find a trace of residual gas in oranges that had been fumigated with hydrocyanic acid gas, in the propor- tions recommended for actual practice, for three hours and then allowed to remain in the open air for a half hour. He states that ‘‘similar experiments were made on samples of apples and lemons * * * ‘with the same result.” Townsend (22) reports that seeds, whether dry or moist, are capable of absorbing hydrocyanic acid, even when its concentration in the atmosphere is very low. He fed fumigated seeds (corn: and’ wheat) to mice and concludes from his experiments that “dry grains and other seeds treated for several days with hydrocyanic acid gas of any strength will not be imjured for food: * * * Damp grains and other seeds treated with hydrocyanic acid gas of any strength, even for short periods of time, should not be used for food until several hours after removing from the gas.” Schmidt (21) fumigated peaches, plums, pears, lemons, and apples with hydrocyanic acid gas, apparently in rather high concentration. He placed his material in a chamber of 9.4 liters capacity and, m the course of a half hour, carried over into it by means of a’stream of air the acid freed from 20 grams of potassium cyanide. “ He ‘gives no values for the rate at which the air entered. If the stream of air was just strong enough to get all the hydrocyanic acid over into the chamber, without carrying any out, the atmosphere surrounding the fruit would contain about 78 per cent of the fumigant. ‘This ‘is equivalent to treatment with the gas from 213 ounces of potassium cyanide or 160 ounces of sodium cyanide per hundred cubic feet, which would be from 50 to 150;times as concentrated as that used *H. D. Young reports that the workmen engaged in citrus fruit fumigation in California often hang their lunches in the trees which they expect to finish about lunchtime. Immediately after fumigation the lunches are removed and eaten with no ill effects. i ABSORPTION OF HYDROCYANIC ACID. ros 3 in practice. Schmidt probably did not get as high a concentration as this, but it must have been very high. ‘This idea is strengthened by the fact that he reports marked physical effects on his fruits. Some of his results are shown in Table 1. TaBLe 1.—Hydrocyanie acid on fumigated fruits (Schmidt). | Hydrocyanic acid Length | present. Fruit. ee gated. | After} | After 48 | hour. hours. NLL 8 chs 00 Sale GR es ety et M: Hours. | Percent. | Per cenf. EAC DESEE BIRNEY: GENTE Yuta AAP EES AMMAR SERIE OAS? Ah A AMEE 2 0. 33 0.05 Dens Seat be be ras see edb: Aa ee ipcte eet Sore. co aescsse es fens oEes| 4 - 06 . 02 ESTES RR er ae APOE Seg Ss SORE geek eek Saha cohen a kncee coe ie 4 | . 04 . 006 DD) Oe ce aero ee EEE, PUES EC). PEPV IR. ASE STE Vets Se ay teat 20 | . 03 1,008 Te eR Ve lee 9 Te AEE ee Oe A eee ee ie | . 02 005 BGR E PRIM PARSE RES ACA MA IEN NAD Ao) SEAMED Pe OED coh DEA By 8 20° | . 02 2 008 DFUPSA seh aate eebe eer aNeL cet stsyck o.- 2. . obec. oye8) -gee5t denice 5. - Ol 002 1D) OS rR P EE AE Ae ee ok ol CRP s AU Wane) RE woe SHE Nash's een ets 24 16 08 Bemons} 4 Fey AT BOT eT Pe ey See iret ees ae) 4 | » O03 s) EEE ree Ciera Ona Bete 5 ims so rey Sg. oa oe 20) Ve st S07 3,016 124 hours. 35 days. 314 days. Schmidt found that peaches which had been fumigated for 18 hours gave off enough hydrocyanic acid to kill mice which were put in a jar with the fruit. He concludes that all fruits take up gaseous hydrocyanic acid and that certain fruits, for example peaches, take up the gas from even a very dilute atmosphere of it, so that it is pos- sible that eating such fruit may cause some injury to health. Quaintance (18) believes that very little, if any, gas is taken up by, apples during fumigation with hydrocyanic acid.. He and his associates have eaten freely of fumigated fruit, sometimes within 30 minutes of its removal from the fumigation box. These apples, of course, were first wiped. | Roberts (19) states that hydrocyanic acid fumigation does not injure any ordinary article of cargo. | | Howard and Popenoe (/2), in describing the method of fumigation | against household insects, say ‘Liquids or moist foods, as milk, meat, or other larder supplies that are not dry and might absorb the as, should be removed from the house.” The inference is that other oods will not absorb enough of the fumigant to be dangerous. Their statement is apparently not. based upon experimental evidence... ‘Bail and Cancik (3) say that fluids and moist foods should not be left in rooms which are being fumigated. They state that Heymons (11) found that fumigated flour was unchanged and nonpoisonous and that they found the same. to be true for bran. . After fumigating a food warehouse it is recommended that the food shall be used onl after airing and that grain be shoveled over several times... | Bail (2) reports that. Herr. Hofrat v..Zeyneck found that after fumigation with,1 per cent by volume of hydrocyanic acid gas (time . not stated) raw meat.(minced), contained 186 parts of hydrocyanic . acid per million, even after airing for 10 hours, moist vegetables con- tained 90 parts per million after airing for 2 days, fine flour contained . 45 parts per pill ion after 10 hours, and bran contained /30. parts per coitiees He recommends. that .all foods, .whether ‘wet. or.:dry,.: be, rémeved before fumigation.» pif oc iat) bovscrsg saw foddner cidt 4, BULLETIN 1149, U. S. DEPARTMENT OF AGRICULTURE. Investigators in the United States Public Health Service (/) fumi- gated bread and milk with hydrocyanic acid and then fed them to white mice. They found that “when exposed to the cyanide gas in the concentration usually advised for fumigating tight compart- ments’? they “did not absorb or adsorb sufficient cyanide to cause symptoms when fed to white mice.’ With double the amount of hydrocyanic acid, ‘“prolonged”’ exposure, and no aeration after fumigation, death of the mice resulted, but ‘‘after one or two hours exposure of the food to the air no symptoms were produced.’ They summarize, ‘‘ The conclusion from these experiments is that the pos- sibility of food poisoning occurring from food materials exposed to cyanide gas is extremely remote.” Lubsen, Saltet, and Wolff (1/5) state that hydrocyanic acid can be used for the destruction of insects in flour and other foodstuffs, since - it does not affect foods, except milk and other liquids. Marchadier, Goujon, and de Laroche (16) advise against the use of hydrocyanic acid fumigation for flour. ‘They recognize its value for clothes and things of that type, but think that flour may hold enough of the gas to cause injury to health. They found a hydrocyanic acid content of 82 parts per million in one flour and say that the foods prepared from it (cakes, sauces, etc.) still had the taste of cherry laurel, even after cooking. They do not describe the treat- ment which the flour had received. PURPOSE OF PRESENT INVESTIGATION. There are no analytical data on the quantity of hydrocyanic acid absorbed under the usual conditions of fumigation, except those of Guthrie and of Bail, who give some results on five products, but none which indicate the rate of loss of hydrocyanic acid on aeration. Schmidt worked with excessive concentrations of the fumigant. Experimental work was therefore undertaken in the United States Department of Agriculture to find how much hydrocyanic acid is absorbed under ordinary conditions of fumigation on a large number of fruits, vegetables, and seeds, and at what rate it is given off when. the products are exposed to the air. EXPERIMENTAL WORK. FRUITS AND VEGETABLES. Fruits and vegetables were bought in season in the open market: and in a condition as nearly perfect as possible. They were divided. into three lots. One lot was analyzed without being fumigated, to guard against: reporting as absorbed hydrocyanic acid any which might be present in the fruit naturally. The second lot was fumigated at normal atmospheric pressure (NAP) by the “pot”? method. The fumigant in this method was: prepared by adding sodium cyanide to diluted sulphuric acid in the: proportion of 1:14:2. That is, for every avoirdupois ounce of sodium cyanide 14 fluid ounces of sulphuric acid and 2 ounces of water are used. : : The third lot was fumigated by a modification of the vacuum method described by Sasscer and Hawkins (20). The fumigant in. this method was prepared from sodium cyanide, sulphuric acid, and_- ABSORPTION OF HYDROCYANIC ACID. 5 water in the proportion of 24:1:1. That is, for every 24 fluid ounces of cyanide solution,® 1 fluid ounce of acid and 1 fluid ounce of water are used. The procedure is as follows: The material to be fumigated is placed in the fumigation chamber, in this case a horizontal iron retort with a capacity of 100 cubic feet, and the door is closed and clamped. ‘The air is exhausted until the gauge registers 26 inches. At this stage the gas is generated by introducing into the generator the chemicals in the following order: Water, acid, cyanide in solu- tion. The valve separating the generator from the fumigation cham- ber is opened, and the cyanide solution is allowed to flow slowly into the diluted acid in the generator. When all the cyanide solution has entered, the outside valve of the generator is opened, and the air is allowed to wash all of the gas over into the fumigation chamber. After washing for 5 minutes the vacuum in the Fackiontornen is completely broken. The material is exposed to the gas for a period of time equal to 1 hour from the time the cyanide solution started to flow into the generator. ‘To remove the gas-air mixture at the end of the exposure period, the fumigation chamber should be pumped to a vacuum of 25 inches. The valves of the chamber are then opened and the vacuum is broken. The chamber is opened and the material to be analyzed is removed. Commercial 96-98 per cent sodium cyanide, usually at the rate of 4 ounces per hundred cubic feet of fumigated space, was used in this work, and the gas formed from it when treated with commercial 93 per cent sulphuric acid was allowed to remain in contact with the product for the time indicated. Even this dosage is higher than that now used in practice, usually 14 to 2 ounces of sodium cyanide per hundred cubic feet. : The temperature and humidity were accurately determined and recorded in each case. Part of the material was analyzed immediately after fumigation, and part of it was stored in the refrigerator for 24 hours before being analyzed. Material which is usually pared before consumption was pared and separate analyses were made on the rind and flesh. Hydrocyanic acid was determined, after distillation with tartaric acid, by the method of Viehoever and Johns (23). The results of these experiments are shown in Table 2. TABLE 2.—Hydrocyanic acid in fruits and vegetables after fumigation.' Sodium cyanide. | | Hydrocyanic acid in— y Tick | Rela. | Period 77... Product. pera- |, tive | after i r r rang. || ERG) ADRES esi) a | NAP | Vae. ity. | gation.) pai | Rind. | Flesh. | | | Oz. per | Oz. per Parts | Parts | Paris 100 100 | DET ao Wel per Apples: CUP I Came CLE la) samme | Days. | million.) million.| million. “ile SAU So eS a aS < Sl 4| 64 43 | PGES aa 9 Re an Mie 8s 22 5's bbe lise chad Bu + 64 43 | 2 By leis ots oye fees pastes IDG se oS i eR are ais (eee 2 75 ol 0 0 EN ea oy & ERIE Imray = LOX0 ep haa Eo eee an eee Sl aa ae 2 75 51 0 | 36) [so SSSR ee DQ See We Ne A Pulao ate f 5 72 33 Ope aa 7 6 LD Oe eee eres ck eek eee ZT We 72 33 1 aN can 6 | 2 1D (0) OS 5 apg ae es ae (eS aa (4 74 23 | Quis ae 97 42 12 Tie DLA 5 Ae SR Eg) ye OF Me MO 4 74 GAR cpm cee 16 | 5 1 Allsamples were exposed to the fumes for 1 hour, with the exception of the first pineapple sample, which was exposed for 70 minutes. 2 Sample cut and allowed to stand overnight before analysis. € This is made by dissolving sodium cyanide in water at the rate of 200 pounds to 50 gallons. 6 BULLETIN 1149, U. S. DEPARTMENT OF AGRICULTURE. TaBLe 2.—Hydrocyanic acid in fruits and vegetables after fumigation—Continued. — ‘Sodium cyanide. Rela- Tem ; Product. pera- fife. gee | NAP |, Vae._| ane ity. | gation. | we Rind. | Flesh. pba 1 ese op Sadie eDps ae | Oz. per | Oz. per | Parts | Parts | Parts 100 100 — | per per | per Avocadoes: euifis | cafe) SRS 4; ' | Days. | million. million.| million. ONIGerriper: - e o¥y oot ce cS Be 4| 7 48 | Ost ee eeer 1, 090 220 Del er EL OY. ON OI 6h 23 4| 73 48 |. 1S ae 250 78 Le aoe Coen Spies Page ge: SET 4 NORE! 53) le ares Mien Ae | Que A 270! 150 Date et tee Se ae SAN { PChags Up SEN t BS 170 93 ONerripe * 2608 ~ Pe. 2? | Be | 4 75.5} 72 | O-beRS. 43 77 60 Ope Satin 5 ea en em ie aera 4| 75.5 72 | rE etee rs 95 41 Doty. £41443 s sabe bale 2 teh ER | aor. S| CE aay | 72. | Orbeees. 26 =. 73 il TG? Per tee CEES ce he ea 75.5) | 72 | ot bio A 75 41 Bananas: ae SE LEEE Set) e862 - ed. Eber ee 4, 64 43 | 2.| 20 {rid bataithpees. eas S NRE = Re teree ee ae ree ch a a 51 0 | So.varite | [Ree wnere WoO ODER 7) Gast 3 2) 75 51 | 0 O5f 102) Ait 17. 3G. Tle: es ae Na ee Pee Ly ey 4|. 73.5 40 | Td (Same hee 440 | 110 LID i ee SARS Se BE ial: Pe tae aie ~ 73:5 40 i Nerden ae 97 } 33 Dor itech. Hisgeyele. echo ep ermattct ji 73.5 |) 40 0 epee: 210 | 61 IDO Se ee eee oer 4. Wo Se aes 73.5 40, alice ss. 38 110 | es Beans, string (green): | © ReSh eee sc en abot ae a a hee 4.) 82705 43 OUR ae LOU Sea oe SET ef ONG Sk TICES: EF ORS | a) aes [ot ag 1 ogg EEE Peek is LD Yi gd a tT AS eee 8 4 | == APA |. T165 43 Oyj; A480 jt bes eerrrre 1 ee a Ae Sean Pet NE AM eet t oe | 77.5 43 1}. 440 | ee _ Paes pea ces Beets: | | OT Et SO CN er OO SN dad im Soe | 4| 64 42 9 10 eee ED) ene eee ee Ree er ee ee 4; 64 42. 0} 1602 he jrttcteee Dor pee cays: shi: : Ft tasb ck Tete 4| 67 53 | 0 4g) bereye betepay. Fp) be Bic oie y Biherge aelade oral ae Myer 4]. 67 53 | i BY nts eee Doe. LOT AT OG AVA. D9. 67 53. | 0 BAR AS Tee DIN ee eo Sere Ae a ee 67 53 1 JY ee ee Cabbage: 1 Goods seeiech Fee ELE eee - S55. SANS. 4 64 42 | 0 20 1 334.552 Bosccer ss Mga re eee ee 4} 64 42 6 DAT Stes leo Some DM ae ee se eee SEE ee Se ee 4) 67 39 | 0 190 SS. Se eee BAY ER ied (2020 TRE CE es eas 4| 67 39 | 1 oe ears, | pres! tel Aer RRSP es UPA ASL SPA EN Es 67 39 0 HOO ULE? Ts SAEED oo De ae: eee Sees ry eae 67 39 | 1 B9ihae. Fokeke | sve oeee Carrots: Sond reat ie tbe OE | 4| 65 44 | 1 100%}. 432249 | whtinrt: LE QRS WES BAe SNEED YS ee | Pen te 4 65 44 1 52 | SS ee De Ln nme Se BSE BAe Ree 4 60 20 | ee oe SoS) 170 56 DOr PERE E tees tig nts obo |beeyse 4 60 20 1 eee ee 120 | = TOIT eis os aR Sat ll leg ae ere HGS ote oe 1:7 00 20 LU i eller gs 200 70 DV GRSRR ES SHER ES JOLT EE eek 45 LAS 60 20 | ps SPs -150 | 80 Celery: | DENTE TOs se eek eed ih a ees 8 A = 65 44 0 300) He AG ABR Se IDS PRS an We ok SE ek emacs ae ae s 65 44 | 0) 310 es soett] hese Gre een ee oe oe ete oe ce 2 75 51 | 0° 190} 20 ooo eee irechy liye Wes. oP ae: 4] 67 | 39 fe 0] (0020 oe SEC noch ates Ee een Ree 4| 67 | 39 1 7s Re eS fee UG Pe ee ern yA a See Wee xe 39 0 | (ES Pee eee er Dig en A) A MISY SA ss | 67 39 1} WASLS eae Corn. green, sweet: | PLES Sec ales 8 Ue ee Se goa KEEN a 4| 82 | 5 | 0 2304. ae Guerin 2 5 | A, |i) bl 65 | 1-|~.350|- 2 Sees DOs en os ee. eke ae sees meas 65 | 0.| > ° 480: |. ee Does eee: Bae rigs] Ege f= SRD 65 | 1 | aes eee ror ak Cucumbers: aad STI tae ee ele 4| 64 42 | 9-110) Sa ee iDiwede sl ee Ee a 4\ 64 42 | 0). 150 | 2a Dy OS ee a re ae octane wensac tonics 4 TERS | 7X. il ee 250 89 BD en aia Bayt Aoi <>) | hb oe 2 4| 75.5 | 72 i ae 58 | 17 IE) ee ee ese os Se o's ye ee (StPdon0 | 72 0 Lee 110 | 98 bie ge ks ee 4 |-------- 75.5 | 72 a fe s33c52 3) Da 45 Dasheen, small corms: Coed iktee Seems. tt | tk 4| 65 44 | 13| 2: 12 | See ; OD) Ose =e et Se Se cE [nce eee 4; 6] = 1} 6.) 54. Oe Dasheen, large corms: add-6. 45h PDs PS eT eras ear | 4) nigh. (24 44 Lg 12: 3s ie eae eS SSE eee ee ee 4)..65) | 44} 1 | Bilas ote binges S Dasheen, tubers: OOO ME Se Soa ee es ts Fa oe 4 63. | 19 Ot sss2ce 15; Trace. Lb ee ees ee SS Zot s Gd J 19 CR peti 15 None. 1D Yr ee eS ee es ae 4 eee 63. | 19 Oh) Sees 13 None ead host ae! bk Be iis pa a Sh 6 | 19 iy 1a eat 13 | None wal Period | Hydrocyanic acid in— Pa a ABSORPTION. OF HYDROCYAN VIC ACID, TaBLE 2.—Hydrocyanic acid in fruits and vegetables after fumigation—Continued. | l | Sodium cyanide., _ Hydrocyanic acid in— te Cree heme pitdela- | Period | 2 Product. Fea) _ pera- ee ar ; ine ide Bees ture. : zt Whole | | | NAP}. Vac. ity. | gation. | | fruit. | Rind. | Flesh | | = | Oz. per | O2. per | | Parts | Parts Parts [> 100°" 100 | | per | (per per Eggplant: CUsfilsa aC fte in ules | Days. | million. Lradttions net illion. Ipeeeer cen te ry nia hd Sle «he, ep OM RIYA. 4.| 78 71: | Gil ees 50 | 54 ES ee St a pe Se Br ar | A 8 71 Ve leceees 44°) 61 100 ee eT a eer ae Zhe * | SS I | 78 71 0) ti ex sea 37 | 43 DOS ss eee eee Be es S| (rg Aah a 78 71 | on eee eee 42 | 42 Grapes (Worden variety): | OLD ree ys na Sy Se are es sore een 4 82 65 | 0; 430152 2k. < Sees See LD 9 VL te Se ST Oe a nel ae ee et se ae £ 82 65 1 230 ee oe 1B 0 SS ee arid See ae ts ee Riera 65 0 420) encoun soe one se De ere Me Oe ee Rem Shee |} - 82 65 1 180; ..5. ON es Grapefruit: | | 1 BW) 0: St Sea ie a Mm sa Re 4; 64 53. | 2 Poe Pete a ieee Ee 8 Te Vs eee eo), YE cei Le oe Ae oa cao 51 | 01 7 PES ey: | a Be east) en eee ee i es 51 0. i ee ih a oe BPs e ce Rees 2). Sa eee: eee 4 73.5 40 Ores ae Ae | 62 2 Pipe ee ee) Ree ae | aa | 4} 73.5 40 ER 50 12 TD Ee 2 5 ee ee eae ee HUNG aS 73.5 40 Osta a 62 2 TAR ee eee a ee ae | 73.5 40 es ee 35 7 Lemons: | ere oes Ca). Se RL ol Bh 4| 64 53 2 | PU Ee eee 9 (ULC 2 ge OS ee | Dh 775 51 0 1a een, Be se 15 SAG SS Ce ae 2)° 75 51 0 88: [head ee, RIMERTIDEG ohne onan Sanwa ees ous ake 4 73 55 | - OP se 230 21 Oe cee eed Mewes tos eRe SOM | 3 Sue ee 4 73 55 OW. cee 220 22 OMA ES ae eet cia sce cement et oe ae 4 73 55 A Se eg ame 160 14 Oia eS eRe Re ee fo oe } 4 73 55 ah SSeS 120 9 "ETL 312 i age ke a Reine | poll eS ee 74.5 58 (Ol aie | 290 11 Yea dla g ROARS RR, rel ee ee 74.5 58 rd We oteare 2 |. . 350 10 PUB OA acme ot Seah, Mok cca eet CE ea ee 74.5 58 |} 1 eee 110 17 DOM eee Cea ae ze Sees See 74.5 58 | eee 120 it Lettuce: | EAN eee te en ee es Ne te UA 4 65 44 0 | 390. fate MDlne one 1D 17 Ia Ses ea i! De 4 65 44 0 Pr (Oey eee ae AEE A TPEnT NO Tea oie Baris tenet ale Sala ean nl Popa Bd 4 67 39 0 10+ pratt ee ees NC: Sommer ME Suh as Sea set OE 4 67 | 39 1 rh eee a, (arse DO Sa hwe etek BO ed ot ge AM anses 67 | 39 0 200 = |r SR SSE Se aD) OS reebrsc lee tastier oles ees 67 39 1 AGA LE $2 SSO Soho. Mameyea (Lucuma mammosa): j C5 Tid Seal Hes a cS a Sa 4 78 7h Olean 48 | Trace. Oey eet es ame ete eins sok | 4 78 71 de dsc eszise 23 5 Green see! 1 oh pol pe Aay cess 78 71 Oots222 sees 54 | = LOA epsh og ae ee Eee APT oS wes 78 71 Ae seee 11 | None. Mammee fats (Mammea americana): Teac Le i 7 een eee 77.5 43 i Paar 150 | 20 Mango ( Mangifera indica): Green Asott) Ee CEN pet Oe en eS | Fa ie (3 7 hs ee Oe 140 | 76 _ ere: 2 ae Se Bene ee 4| 78 71 1 Eee 64 | 16 Green ‘arm = A sis eee ee 7k | eat aa ae 78 71 Oe 140 | 32 eee eee ee a Ds aE oe 78 71 rer eo a 80 | 17 Muskmelon: | iD. 6S. 19a Se ee ae ee eee | 41 79 66 Oc hi ae oe 68 | 22 ibe d tle a ee De 4/ 79 66 ee ee 54 | 28 1G sec eee ee ee AGW ees 79 66 O /Ss2 e222 63 | 5 SBS 0: SON ce aie PS ee 79 66 A. J 00 S228 70 | 21 Onions: | SET ips eee pa Ce 4 64 42 0 PAS Pa epee eck 8) [ee aera DOE ae ee ee sa Recent ec ccm + 64 42 0 774 UE RES a Ste a ATA Or ete a Pa ea so ara are cee motels ou 4 78 71 Oo iraces sae fee oe Nn oem ene te nia sche ce dl ech" A L 78 71 A} Non@uto se 2iee Rese Do eat alreln Seis es 7 NS Wiens eee 78 die Os) "Dracecaliso ns AoeeNs Se oes ‘ ER es a 4 | Rs ee 78 71.| 4-| None: ites Gey ai Oranges ( (Cuban) (Florida): 3 Sa EL oe 1], <= .2-2]-2 ee: |eaeaeee| 5 |.......-| None. | None Paie Clee aise ris oS orc crandomaee Foe EE eae oe oa Bitte 2 Bie Bes | None. | None. TR DO Yee ot es Sea eee eee cs eee | 4| 64 43 Z 39) [Sin cuss eee ON Snes ee ee a a | Dil ea5 51 0 Pts eee eee 1D Cone See Ge} see le a Cae Bat De Wks DD 51 0 D+ bose he RMI eee ay ino se eer ck ae. epi bad | Al eggs 55 Onjscssenss | 240 | 11 pee Mee ee Fe Bia ria eos 5 55 | O}ssees.ss}-> 240 fi De 2 a eee 7.) aig ae | 4|- 73 55 | i en b.. td 11 42 2 Ste ae or Gece Pipe 4} 7 55 1 eee | -- - 100} il TI a i 3k A oT a ie y 74.5 58 Nf ae rae olih 3 Dacre pisos’ $90 n34-5 ~t === ai ego Be 74.5 58 iY (ay Remy | 100 | 3 ee eel sidan 's vase tap crept eyed | 74.5 58 | UG epee | 94 4 JD 1 NEN a 6 ge a ya ees Nee |) 74.5 58 | ev ices Serie 8&7 4 * Fumigated at Key West, Fla. BULLETIN 1149, U. S. DEPARTMENT OF AGRICULTURE. TABLE 2.—Hydrocyanic acid in fruits and vegetables after fumigation—Continued. Product. Parsnips: G Peaches: Ry es AN Sa te ea TER ECS | eh a Se eae Ie ee ana Ya TD XO) S pa Sp Siereh ARR LRAT AER AN Peppers (green): VN ROGT ao. LE Ae eg Gs, Sa ee 121) 0) Dine eR Sali ae aD D Rp erG balk) see awe VA bes RCE CSL) PE ei LiL Ld a JDO) Ne LON I eat Ee OED Plantains: Good Goo 3 Fumigated at Key West, Fla. 4 Pod. °8 feet from generator. 6 6 feet from generator. 8 14 feet from Sodium cyanide. Hydrocyanic acid in— . 7 Tem- | Rela- | Period |. sa sees sana a tive after ture, | Bumid-) fumi- | wrote NAP | Vae. ‘ ity. | gation. fruit Rind. | Flesh. Oz. per | Oz. per Parts | Parts | Parts 100 100 per per per CU: fl-a) Cu ft: oR. Days. | million. | million. | million . ag 4| 60 20 | (0G mba aS 88 Dae alg 4 60 20 by ee ea 280 71 os Seana ea GOhgcee) GOD CN aac 230 85 YB lea ta ae 60 . | 20 | ALI eee Ws rare 80 50 Wey A AD iat \ndostey 51 Qe icemes sre 130 65 Pa 4| 73.5 51 rl Shape cu 52 32 fT | me a 13.5 51 (NH iB fee 92 3 ANI Iasi eae 1855) 51 1 Rages Ya 130 12 Bere aes 4 (oH 51 (1 SMa 72 22 GSE LS 4 (Babe! an ies Wegner costes af}? 18 11 Axi te Sp hws fe. 5) | 51 (gt fame Sn tle 92 14 ANN AE cA: ne 1855 51 bp ube Sar 16 3 Ue 4 71.5. | 43 Qiks eas 4 530 1,100 hee BRE 4 (be a 43 TET cape Hep 520 © 7) NE Vee aieee | 43 (Og ae ng 4420 | 1,400 7 ND RE CMS og Ml 1s a 2 4230 200 RE A 4 Sora 65 0 310) [ere eeoealoe eee PR Ne 4 S20 65 1 220) fee oce eee Aah) Si Nea tes 65 0 Ey. pam as Ageia Bw a Se 65 1 120) ie ok eee ae in| 4 “al 49 0 poh i aR: | ME poate ees 4 71 49 0 WB DM PR ia DS ree Leet dah | 4 71 40 Ooo has 180 88 OI eats Sane 71 49 0 60) 5 aes eee 7 SALES Oe i SN 71 49 0 E58 Nea FORESD IS fn ic OH gene ese ee Ae 40 (0 Nes aearara 100 14 7 (pier ake at 71 40 (Yai cematat Arte 100 6 VE ad ea Haba Oa a 70 ie tee 23 6 a LS ts arr 70 70 Puen saute si 6! None AIPAC Dosey (asec tS es PR EAU IGS MR ce Ir Hs Nay a Yoana me LAS, (pete MENS SI an ma SS 62 INONGs |. eae eee 11 ele SN p27, Mi ae (eo 4S NONE. tee on ealesee eee 11S al ean ea Pd tr ely mln avs 8 4G NONE. see chee DE AGH 2 ale SH Be SRA Ps SEN 4° |TNOn@. 2 eee Geen AG eee a A ee a Ps 4 |S None. hee eee ee LG es a Me th SO poe eeeeen 3 (E NONE. ficastee oe eee TOD bes soa BOs pe eye eae 3 |§None fw sien ee |= otines USI LEaE 4 78 71 [Gy Fee eee Pd 490. 130 sires aaa 4| 78 71 ya agains che 2a 56 7a SION cape: 783 | 71 a alee 170 160 a a Copan ic gee| 71 118 eager /@ 140 50 | | 2 Benes) Uavea”.| 4 Gonna 44 1 y, A es ialicatcoiiine PS ARE res Bese hanes | 4 65 44 1 $3.) Sr als eee 79 as aden aed al 72 33 Ojp sot ee: 39 10 faba) Aylin BR 72 33 BS HE ceca | 21 ee eee a 4 68 34 Obie seen 69 31 Ree iN, 4 68 34 1 Be irate a 82 21 Apap eat, 4 65 44 1 bs AR Bane eMail a ae or LAR SUNY 4 65 44 1 1 Oe 2 eal eee gas dae NI, ee 72 33 QP aa eee ~20 6 7a 72 33 ios Ces ae 8 2 Pastel Sith 4} 68 34 | Oy eased 30 3 mag 9 wl | 4] 68 34 | Tee 8 1 ee Zale O 12° 2000 tae eee eee ie UE 4| 64 42 | O90, Cee eee St CRSA ape 4 63 19 | 0 PTO Te Se ale ae eee spe AE yt) 4 63 19 | 1 4G he ace see ee A? Pa See beer 1g 0 NOL MEMS oe ae | a eae ee i 63 19 | 1! 54 eee Sue ae 74 feet from generator. generator. Re ot Bull. 1149, U. S. Dept. of Agriculture. PLATE lI. Before fumigation, After fumigation. EFFECT OF HYDROCYANIC ACID ON FUMIGATED PRODUCTS. ABSORPTION OF HYDROCYANIC ACID, 9 TABLE 2.— Hydrocyanic acid in fruits and vegetables after fumigation—Continued. Product. Se ee i ry were ect ee ee ee ewe ee eee ee eee Tangerines: Ripe ee ee ee ee a | Fres Sodium cyanide. NAP | Vac. Oz. per| Oz. per 100 100 cu. ft. 4 serene eee cc eee - ec eteee a a sete cece eee ne eee HUGS SII 75.5 CrOVOTOWor ono On ity. Period after fumi- gation. Hydrocyanic acid in— SSss SSSsss SSSSSSESS BSBoss ee a 2 Sample cut and allowed to stand overnight before analysis. Days. Whole| pind. | Flesh. Paris | Paris | Paris er er per million.| million.| million. Pele bo 550 120 3 he SR 110 34 ae NaS bei 450 110 pd aed 50 15 bd os BS 130 51 LG RUST 110 15 Maer 5g 94 36 a Ae 2 ees 55 29 Lost IM feed Weta be Ua A Ire i bee war et 1 ed Sb bo te Ly. ie beeen te | cco t= a 15) gly cl 9 ap Ey age 37 te (ela Bas ea bine = = Dial heya nahetty | oes Gita le fet ee IBA ES og > 20) eae ee [se oan. ae DAs | seh oe AN aa ee Fla. Gieeaae [tee pe ae oe Pa eget 400 | 59 fone Gaye. 85 23 ie ee 430 54 SEES Bes 98 16 fa Ua Ree et Be ee | 8Qsit .2eeee Sipe ess eee Seles 74 17 Jem ERE 28 23 eee as 56 12 wearaianrs 14 9 (pW eewe ngs oh Weare? S42 | Dil eeeacies. oy telnet STOP! bid. COLE OD Ae sirens Deke ere Se ge 5 Hal i ir el Sys al em Aad es Sd Abeer bid atieee ene sted | VO 4 ee ae BAe Rage ad 120 53 ay. #5NRe 45 31 E Jeni eate 340 120 Sie i Se 99 43 pe cenenel 5 | None SS ae 4 | None 9 Sample stored at 70° F. ! All the fumigated fruits and vegetables absorbed some hydrocyanic acid, but the quantities absorbed differed widely for different prod- ucts. In general, the hard-skinned products, such as apples, oranges, lemons, watermelons, and grapefruit, had comparatively little of the gas in the flesh or edible parts. On the other hand, fruits and vege- tables of a succulent nature or containing much chlorophyll absorbed larger quantities. Of course, in many cases these products are cooked before eating, so that most of the hydrocyanic acid, if not all, would have been driven off before they were eaten. The physical effects on the products treated at the rate of 4 ounces of sodium cyanide per 100 cubic feet are noted in Table 3. 10 BULLETIN 1149, U. S. DEPARTMENT OF AGRICULTURE. TABLE 3.—Physical effects of hydrocyanic acid gas on fruits and vegetables. Product. Effect of hydrocyanic acid. | Product. | Effect of hydrocyanic acid. Applesie.p 2 .>.bok None. || Muskmelon....... _ Decided softening. Avocadoes........ Deterioration very much has- || Onions...........- | None. tened. | Oranges! 2. eat Do. Banangsssss osc: Slight yellowing of the pulp; || Parsnips.......... | Do. some darkening of the epi- || Peas.............. | Do carp. Peachase esas sceee | Do. Beans (green, |} None. SORES) cee esc see | Darkening of the epicarp. string). Peppers (green)..., None. HS CCLSE ce ree ecb Do. || Pineapples........ Do. Cabbage...........| Some wilting and yellowing.! | Plantains........., Decided softening of the pulp Warrotsi. gs -.--=be's None. and browning of the epicarp. Celery). 2022. 5.6: Severe wilting.! | Potatoes (sweet)..| None. Corn(green, sweet) | None. Potatoes (white). .) Do. Cucumbers........ Do. Moalsiive erence Do. iDasheen'= 3: --...<. Do. Sapodilla.......... | Do. Heoplantoc. 25. Do. es quash ees sae | Do. Grapesaines oe ee Decided softening. '| Strawberries ....-.| Decided softening and severe Grapefruit ........ None. | _wilting.1 emonss ss es es Do. Tangerines........ | None MeELUCE Seen ee nee Se Immediate and severe wilting.! || Tomatoes......... Do. Mameyea.......... Softening. |[abrpoo Ss oo Ss SS Do Mammee apples None. Watermelons..-...) Do Manso Ns eee see bs Darkening of the epicarp. 1 Deterioration was so serious that the product was not marketable. Some of the fumigated products show a tendency to speedy decay, probably because of a reduction of their natural resistance to putre- factive organisms (Pl. I). This is particularly noticeable in the case of the avocado. Refrigeration does not seem to prevent the disin- tegration to any great extent. No very direct relation seems to exist between the quantity of hydrocyanic acid absorbed and the damage to the tissues. Green peas and string beans both absorbed large quantities and yet showed no deterioration. On the other hand, mameyea, pears, and musk- ioeon contained comparatively small quantities but deteriorated oreatly. Although Schmidt (21) reports severe deterioration of peaches due to fumigation, the lower concentration of gas in the experiments here reported gave no such effects. \ SEEDS AND FLOUR. Experiments with seeds and flour were undertaken to determine the following points: (a) The quantity of hydrocyanic acid absorbed during fumigation; (b) the rate at which it is dissipated on storage; (c) the effect of evacuating the chamber several times after fumiga- tion on the quantity of hydrocyanic acid retained by the product; (d) the relation of the concentration of the fumigant to the quantity absorb ed. Navy beans, white field corn, cowpeas, wheat, and flour were tested. Sacks containing about 15 pounds of each were fumigated with the dosage indicated, by a modification of the method of Sasscer and Hawkins (20). In the first series of experiments the products were put into the fumigation chamber, and air was pumped out until the vacuum gauge registered 26 inches. The hydrocyanic acid gas was then introduced, allowing 5 minutes for generation and 5 minutes for washing the gas from the generator to the fumigation chamber, after ABSORPTION OF HYDROCYANIC ACID. . 11 which the air was permitted to enter until normal atmospheric pressure had been attained. After the products had been exposed to the fumigant in this manner for an additional 50 minutes outside air was drawn over them for 10 minutes to remove the hydrocyanic acid. They were then taken from the chamber for analysis. The treatment of the second series was conducted in the same manner as that of the first, except that at the completion of the 50-minute exposure the chamber was again evacuated until the gauge read 25 inches, air was introduced until atmospheric pressure was reached and, after a further 2-minute aeration, the products were withdrawn for analysis. The treatment of the third and fourth series was the same as that of the second, except that the evacuation at the end was repeated once and twice, respectively, with intermediate aerations of 2 minutes in each case. Determinations of hydrocyanic acid were made, after distillation with tartaric acid, by the method of Viehoever and Johns (23), on the day of fumigation (except in the first series) and at intervals thereafter. A delay with the first series made it impossible to con- duct the analyses on the same day. ‘The products were stored in*a large, well-ventilated room during the intervals, at a temperature of about 70° F. The results of the examinations are recorded in Tables 4, 5, 6, 7, and 8. TaBLeE 4.—Hydrocyanic acid (parts per million) in fumigated navy beans. | | Number | : Hydrocyanic acid after— Sodium | of times re es a cyanide cheeet | | | | | i ciated Oday. _lday. | 4days. | 7days. | 14 days. | 30 days. | 60 days. | 90 days | | | ome) | | | | Oz. per | | | | : 100 cu. ft. | | ) Mls ees Gs esses se. 3.3 3.3 Dies. 0.8 None} lig. egies 1.2 1.2 | 18) |< Nome... fen. |borecabe. eeae: Linas 273 | SP ibe ee Geli] Mack nk oe .8 .8 None, } eee aber ana noe arrest De 0 62 5.8 1.7 15, (chon 2 1.2 0.8 0.8 TERE ee i 25 8.3 320 MS Co) ee ie }.2 4 Pree 0 2 12 5.0 2.5 HF | 1% 1.7 1.2 8 Dea se | 3 8 5.0 2.5 | Tai ey 12 EO) .4 7 eee 0 42 6.6 3.3 B28) | | 2.5 a7 V2 12, cS eae 1 25 10 3168) 3.3 2.9 | 2.9 nl: sl keiy EA ee ee 2 25 8.3 4.2 3.3 | igh fit het Fz 1.7 Bes seit. 3 17 6.6 3.3 255 2.5 2.1 2o1 ae Beet 0 33 5.0 4.2 22.4 3.3 2.1 9.1 rey 2) Seen 1 33 10 6.6 S84 5.8 5.8 5.0 4.2 Ge. ay: 2 | 33 6.6 5.0 50} || 5.0 3.3 3.3 3.3 Gace) 3 | 33° 12 6.6 6.6 | 5.8 | 4.2 3.7 3.3 if | | TaBLE 6.—Hydrocyanic acid (parts per million) in fumagated cowpeas. Number | Hydrocyanic acid after— F of times de: chamber | eee 0 day. 1 day. 4 days. | 7 days. | 14 days. | 30 days. | 60 days. | 90 days. Oz. per 100 cu. ft. i aaa OV ee 6.2 4.2 3.3 2.5 1.7 PD 1.2 ee Tee Eas 16 5.0 4.2 25 OX Teva 1.7 ee 73,4 ES aa a 4.2 4.2 4.2 2.5 17 a) ug ies eee Sms 3 AEN Aa 4.2 4.2 rae | ih} 58 1.2 Te Ast 0 56 16 3.3 2.5 ee ee 1.7 1.7 Die wins Be i 33 16 5.0 Road Ze 5a 2aU 2.1 E76 DW 2 21 17 5.0 4.2 2.5 2.1 7 1.7 BIN 3 16 11 4.2 es) 353 2.1 2.12) 4.7 Bec Sh 0 83 33 17 6.6 5.8 5.8 Bo 2.1 hiss: Va oa | 1 50 33 13 5.0 | 5.0 5.0 4.2 3.3 Ber els 2 42 33 8.3 5.0 4.2 4.2 4.2 3.3 11 Gaels: 3 42 23 6.6 5.8 5.8 5.0 ser 3.3 Bsc 0 33 17 8.3 8.3 6.6 4.2 4.2). 1c2 aig Gee 1 83 27 8.3 8.3 7.5 7.5 6.6 5.0 Gees 2 130 27 17 13 5.0 5.0 5.0 4.2 Gerri a 3 100 40 13 12 10 6.6 6.6 5.0 2 No hydrocyanic acid was found in unfumigated samples of any of the products, showing that none of it was naturally present in them. All of the seeds absorbed hydrocyanic acid on fumigation. The results obtained on the day of fumigation have little comparative significance, since much of the gas was loosely held and variations of three or four hours in the times of standing were unavoidable. They show, however, that the quantity then present is fairly large. Most of it disappears during the first few days. In fact, in most cases the hydrocyanic acid content, on the fourth day, was not more than 5 parts per million. After this time there was an extremely slow dis- ! ABSORPTION OF HYDROCYANIC ACID. TaBLE 7.—Hydrocyanic acid (parts per million) in fumigated flour. Number | TaBLe 8.—Hydrocyanic acid (parts per million) in fumigated wheat. P of times Sodium | chamber cyanide. Ae uated. Oz. per 100 cu. ft. oe yo, peta © 0 reer ere ey =o 1 We PS SAREE 2 1S ee 3 DB ae Res be 0 ON ap Sao es S 1 PILES MD Dy yee SA: gare s 3 Yael eee 0 A eee 1 Air 03 aie 2 AL ety, 20 3 (a aespiin “sere 0 Gers ays 1 Ga et 2 Gee eae hie 3 Number Sodium | chamber cyanide. was evac-| 9 ga uated. y- Oz. per 100 cu. ft. Dnvtd «<= (Nil Sean eee 1. ASS | Sale oe 1 es PAPER Se” See Ue | hy apap 7a a eg a oy 7] ates 0 17 | eee 1 21 ye oe 2 13 21 EES 3 13 Ans 0 17 = Th of Ie 1 25 Ze een SO Nag 2 17 Ais sz 3 17 Grates 0 17 Gres 1 25 Tee 2 33 Oo arose, 3 25 1 day. PHAM WAAA WAH ANXNDD WAH WOMDw Hydrocyanic acid after— 0 day. or Oo | 170 | 1 day. WOOD Dew worn Go OO GO Or Www anw? 4 days. wee eee eee ew a ed errr ee ees! sete ree see coc esecces ecceeeceere cer ecceseee 13 30 days. SINAN Hydrocyanic acid after— 4 days. | 7 days. | 14 days. 3.3 2.5 ed 3.3 2.5 Lest 3.3 2.5 Weed, 2.5 2.9 Se ord 3.3 2.5 5.0 4,2 3.3 3.3 2.9 2.5 3.3 3.3 3.3 6.6 5.0 4,2 5.8 4,2 4,2 5.0 4,2 4,2 6.6 4,2 4,2 e 3.3 3.3 3.3 5.8 5.8 5.8 6.6 5.0 5.0 6.6 5.8 5.8 TR SUN) TPR Ce NINN) WNOM NHNHwWH wOoWwH aa Sess eee PRON SOP Nip NNN y DWNOHD WNON CFP ANID PO PN NWONWS Neh Petre WwWN OWMDW Maiae sas . Sipation, a very small quantity of the fumigant being present at the end of the 3-month experimental period in all but a few cases. The flour differed from the seeds in that, while it at first took up a large quantity of hydrocyanic acid, the union seems to have been extremely weak and by the end of four days, or, at most, a week, no traces of it could be found. Evacuating the fumigation chamber once, twice, or three times to In fact, a sample from the series in which the chamber had been evacuated two or three times frequently had a higher gas content than the corresponding sample in the series in which the chamber had not been evacuated. get rid of the fumigant did not have much effect. 14 BULLETIN 1149, U. S. DEPARTMENT OF AGRICULTURE. _ The quantity of sodium cyanide used had a marked effect on the hydrocyanic acid absorbed by the product. This effect was noticeable after storage for 3 months. MISCELLANEOUS PRODUCTS. In the work of the Department of Agriculture it has at times seemed desirable to fumigate certain other material with hydrocyanic acid: These products have been analyzed, with a view of determining their safety for use after fumigation. The resuits are shown in Table 9. TaBLE 9.—Residual hydrocyanic acid in miscellaneous products after fumigation. Period | : ; Hydro- | after Sodium Ex- " : Product. | fumiga- | cyanide. posure. | Pressure.| cyanic | tion. | acid. ! | Oz. per | Parts per Days. |100cu.ft.| Hours. | million. Beans brazilian eee cies DL oe bate VB be (4) | 1 | 13 | Vac.2 | Less than 4. LEY ESTES BAS eye ead a eae. 7 ave 2 | 1| 13 | Vac. 5 Cotton seed, Columbia: Wihole seed - os cao eee ered Seweeeeeees 4 3 Z Vac. 58 TUS 3S Peto aa Le oe rae oa Sa ort 4 | 3 : Vac. | 110 WARS GS SERN ie Se SA, Se ae aie ed © a ee 4 | 3 =| Vae. | None. Whole Sede: sh. fr see er ote ou Bee eee 4 6 | Pall ie" 530) $3 15S Se go ee ee Aare ee ee eee eee 4 6 | a Vac. | 140 WICAESE ene ee a ea a Rae Nee eco tow ene eee ‘ 4 | 6 | _ Vac None. Cotton seed, Sea Island: Rin olescede reset SS ho Seo kde oeisls sks 4 | 3 2 Vac. | 75 211) Seek ee 3 erp os seen ince mene Pears perch vate re nates 4 | 3 3 | Vac. | 150 IND CAGS ere see ic oak Se oR oe coin ue cciaan 4 | 3 =) Vac None Cotton seed, Trice: | Wihhtole seeds 4 oaeee oe See eae eee 4 | 3 | 3 | Vac. | 66 QS ae De ee CREE epee ae Feces a ee ae eee 40 3. a) Vac. | 140 LUCTUS 3 SoS ee eees tiie eee eee Seale ee 4 | 3 =| Vac. | None WHOLE SCO ie See he ie ees. VR eae eae ee 4 6 < | Vac. | 83 LI CEE eee 8) ere Le MR 2 pats. er TRS 4 | 6) = | Vae 150 AGE RE SR 25 a Ses ee 8 Ae Rte ie BS ts ane ore 2) 6 | Z| Vac.! None Cottonseed cake: | | ORE ee Ee 2 Se te aE ee 1 | 2 Li) SNAP? 8 BB) Oe a ee os cb ate cite Rie. ce see oe 3 | 2 | 1. SNAP i) TD OV =o ot Smee Reps sk A ae ae fe ee 7 | 2 12, |e ANGASR: 5 Gowpeass Groits*..- oe ak. Lo SE eee. 2 a 12 | Vac. 66 Chestnuts: | RWhiole she oe Bye So Se of 0@ | & -f Se 140 Shrelisse oe i Eee eS. Po ek RE 0 (4) (4) (4) 189 WLIPD ASC nS: Soe ERNE NGS -SEMNE C'S Yehnen e L pr ne 0 (4) it oe) | (4) 130 Honey: Capped isoes.. 20 fo Sat ol ee a | 0 | 4) > DNA Trace reapped=-© c.f Rs EEL Re... 0 | 4) lf SNAP WAP PEGI hat. BO RR eee ee | ea ee A 1 + i} ENAS None WinCAPDOG. on... 25. see fge ve see mae ta @2555.8: | 1 2 1 NAP 2 | 1 Several. 2? Vacuum fumigation by the method of Sasscer and Hawkins. 3 Fumigation at normal atmospheric pressure. 4 Unknown. The hulls of the cotton seed and the shells of the chestnut absorb a large quantity of hydrocyanic acid. Unfumigated cottonseed hulls” showed the presence of no hydrocyanic acid. Checks on the chest- nuts were not available, but it does not seem possible that they would naturally contain such a large quantity. Hard rinds on fruits and’ vegetables tended to prevent absorption of the gas. No explanation is offered for this difference in behavior. SN es Oe ee The absorption of hydrocyanic acid by uncapped honey was un-. expectedly low. This was also surprising, in view of the fact that. moist foods have a tendency to absorb the acid fairly rapidly. ABSORPTION OF HYDROCYANIC ACID. 16 SUMMARY. Hydrocyanic acid gas, widely used as a fumigant against certain insects and rats, often comes in contact with materials intended for food. The quantity of hydrocyanicacid absorbed and retained by vari- ous fumigated foodstufis has been determined. All of the products examined absorbed the fumigant to some ex- tent. Hard rinds of vegetables or skins of fruits had a tendency to decrease the absorption. Chlorophyll-bearing vegetables, or those of a succulent nature, in general, took up large quantities of hydro- cyanic acid. Some of the fruits and vegetables suffered physical injury (wilting, softening, or discoloration) because of fumigation to such an extent that they were unmarketable. In the case of the seeds most of the hydrocyanic acid was rapidly dissipated, so that by the fourth day the content usually was not more than 5 parts per million. After this there was a slow dissipa- tion, a very small quantity of the fumigant beimg present at the end of three months. The flour examined absorbed a large quantity of hydrocyanic acid but gave it off so rapidly that by the end of four days, or, at the most, a week, no traces of it could be detected. Kvacuating the chamber after fumigation was not effective in removing absorbed hydrocyanie acid. The concentration of hydrocyanic acid gas used had, in general, a marked effect on the quantity absorbed by the product. This was noticeable even at the end of three months. The quantities of hydrocyanic acid absorbed by various other products were determined also. No conclusions as to the safety of fumigated foods for consumption are drawn in this bulletin. Chemical observations alone are included. Determinations of the quantities of hydrocyanic acid injurious to human health lie in the domain of the pharmacologist. BIBLIOGRAPHY. .. (1) ANONYMOUS. Adsorption of cyanide gas by foodstuffs. In U. 8S. Public Health Ser., Public Health Repts. (1920), 35:1597. _ (2) Bat, OsKar. Ungeziefervertilgung mittels Blausiuregas. Jn Gesundh. Ing. (1919), 42:33-51. and CANCIK, J. Ungezieferbekimpfung mit Blausiuredimpfen. Jn Centr. Bakt. Parasitenk. I Abt. Orig. (1918), 81:109-124. (4) Bett, J. T. . How to destroy cabinet pests. Jn Can. Entomol. (1877), 9:139-40. (5) Coruette, C. E. Insecticidal fumigation in ships; with special reference to the use of hydro- cyanic acid and to the prevention of ship-borne yellow fever. Jn Med. J. Australia (1916), 2:384-7; 405-9. (6) Cree, R. H., Facet, F. M.,.and Wricutson,.W.D... . Hydrocyanic acid gas. Its practical use as a routine fumigant. In U.S. Public Health Ser., Public Health Repts. (1915), 30:3537-50. (7) Dean, G. A. Insect control in flour mills. Jn Am. Miller (1922), 50:752-3. (8) and Swanson, C. O Effect of common mill fumigants on the baking qualities of wheat flour. In Kans. Agr. Expt. Sta. Bull. 178 (1911), 155-207. (3) 16 BULLETIN 1149, U. S. DEPARTMENT OF AGRICULTURE. (9) Froripa Srate PLant Boarp. Third Biennial Report. Jn Fla. State Plant Board, Quart. Bull. (1921), 5:47-8; 99-101. (10) Guruertin, F. B. Fumigation of fruit with hydrocyanicacid. Jn Agri. Gaz. N. S. Wales (1898), vs 1191- a (11) HEeymons. : > bas Der Miiller (1917), vol. 39, no. 21 (quoted by Bail and Cancik, oc. cit (12) Howarp, L. O., and Porrenog, C. H. Hydrocyanic- -acid gas against household insects. U.S. Dept. Agr., Farmers’ Bull. 699 (1916), 8 pp. (13) Liston, W. G. The use of hydrocyanic acid gas for fumigation. Jn Indian J. Med. Research (1920), 7:778-802. (14) Lopreman, E. G. The spraying of plants,-p. 148. The MacMillan Co. (1916). (15) Lussen, C., Satter, R. H., and Wotrr, L. K. Over het gebruik van blauwzuur als insectendooden middel. In Nederl. Tijdsch. Geneeskunde (1920), 1:881-7, through J. Am. Med. Assoc. (1920), 74:1614. (16) MarcHAvDIER, GoUJON, and DE LAROCHE. L’acide cyanhydrique agent désinfectant des farines. In J. pharm. chim. (1921), ser. 7, 23:417-20. (17) Montcom_ErY, J. 1? Fumigation at Florida ports. In Fla. State Plant Board Quart. Bull. (1920), 4:117. (18) QuartntTanceE, A. L. Fumigation of apples for the San Jose scale. U. 8. Dept. Agr., Bur. Ent. Bull. 84 (1909), 39 pp. | (19) Roperts, NoRMAN. C yanide fumigation of ships. Jn U. 8. Public Health Ser., Public Health ipa: ( 1914), 29:3321-5. (20) Sasscrr, E. R., and Hawkins, L. A. A method of fumigating seeds. U.S. Dept. Agr. Bull. 186 (1915), 6 pp. (21) Scumint, H. Ueber die Einwirkung gasférmiger Blausiure auf frische Friichte. Jn Arb. Kais. Gesundh. (1901-2), 18:490-517. (22) TowNSEND, C..O. The effect of hydrocyanic-acid gas upon grains and other seeds. Jn Md. Agr- Expt. Sta. Bull. 75 (1901), 183-198. (23) VIEHOEVER, A., and JoHNS, C. O. ‘On the determination of small quantities of hydrocyanic acid. Jn J. Am. Chem. Soc. (1915), 37:601-7. (24) Woauium, R. 8. Hydrocyanic-acid gas fumigation in California. U.S. Dept. Agr., Bur. Ent. Bull. 90 (1911), p. 1. ADDITIONAL COPIES OF THIS PUBLICATION MAY BE PROCURED FROM THE SUPERINTENDENT OF DOCUMENTS GOVERNMENT PRINTING OFFICE WASHINGTON, D. C. AT 5 CENTS PER COPY PURCHASER AGREES NOT TO RESELL OR DISTRIBUTE THIS COPY FOR PROFIT.—PUB. RES. 57, APPROVED MAY 11, 1922 Vv