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/. ;n .W. Mel.. 195.'. 10. 255. by copyr,thh1t ^ItfA *.1 :Tifc 1 7 U S CvJ HEALTH PROBLEMS IN THE MANUFACTURE AND USE OF PLASTICS BY D. KENW1N HARRIS From Imperial Chemical Imhi.vries Ltd.. flaxtits Dhisk"(RECEIVED FOR PUBLICATION JUNE 8, 1953) v increasing variety of plastic materials .. ced during the last few years is due mainly .ne ability of the modern chemist to synthesize the vc.il compounds from which plastics are made. h.iiis of most plastics today is the synthetic and its introduction has made available substances hitherto unknown in industry. .- I plastics are manufactured to serve specific roses so that the synthetic polymers can no :c be regarded as substitutes for those found .illy as cellulose, rubber, and proteins. A wide -v of materials can be made from them and so c-ted as to meet the actual properties required . iy particular application. ' addition to the polymer, synthetic plastic . uls contain varying amounts of other chemicals ..oulysts, accelerators, stabilizers, hardeners, is. and so on, which are added to assist icul.ue polymerization or to influence the . lies of the final material, such as colour and ' iity. Most polymers are chemically inert and ordinary circumstances the final plastic should be comparatively harmless. It is .dly difficult, however, in practice to effect ' -te polymerization and traces of free monomer - chemicals may be present which can produce pathological conditions such as ` '!>. . ''sliced chemicals may be broadly divided group', condensation and addition polvf hey may also be divided into thermoplastic 'insetting types depending upon whether the - is softened or hardened by heating. The ... that takes place on heating the thermosetting ' is irreversible. f OMinssVTION POl.VMFH PLASTICS ...nsation polymers arc usually formed by the . ! molecules with the elimination of water 01 vr compounds. Formaldehyde Products The thermosetting types in this group are those formed by the condensation of phenol, cresol, urea, or melamine with formaldehyde. In the manufacture and use of resins, glues, and moulding powders of this type free formaldehyde may be liberated under certain circumstances, tne amount depending on such factors as the ratio of the ingredients, the degree of condensation, and the addition of other chemicals such as hexamethylenetetramine. For the sake of simplicity these products are discussed below in two separate sections depending upon whether they mainly affect the human body externally or internally. Effects on the Skin.--Formaldehyde and hexantine are well known as primary irritants of the skin and mucous membranes and many factories handling resin glues have had cases of dermatitis at some time or another (Factory Department, 1943/ Schwartz. Peck, and Dunn (19431 mention a factory of 800 employees where 600 cases of glue dermatitis occurred during the first months of operation. In a small leather-factory the incidence of dermatitis was highest (28%) in the section where " notorious sensitisers such as formaldehyde, lacquer and Bismarck Brown were used" (Squire, Cruickshank, and Topley. 1950). It has been stated that the actual substance responsible for he.xaminc and formaldehyde dermatitis :s formic acid (Schwartz, Tulipan, and Peck, 194" There is another factor that should be considered in assessing the predominant cause of dermatitis as the result of handling some of these products. In their usual commercia' form, for example, these formaldehyde gluts and resins will adhere to the skin and rapidly harden on contact with it. and Little (I950> considers this to he the primary cause of the more serious outbreak* of dermatitis from them. Mayers and Siherbu-e '1936) stress the great variation in the length, of time ranging from a few  L\t '4 tilt' ' in IMI, ra i ,n .nJ . he .iHcr w.ll .ind v4ied the .tlms `nen This ''uin TUll- the O" - iw. o: thj to HEALTH PROBLEMS IN PLASTICS INDLSTR > -u'-' ?r.l dor>a which reacted very slowly hi although the oedema ol' the face subsided .. Jay or two. Shortly afterwards he took a :a!r'' holiday when the condition cleared entirely. ire third type of lesion is one in which the ;ipLion may combine the clinical features of the ^ e.tr 194? 1946 1947 lv4h |94V I9J0 P` UtlCliun <l**% hhu 100 1*0 194 260 570 447 DdmiiUiu-. C a-c% 9 10 11 s 16 15 LxM 1.23* i,:m 80 20a 46 39 . 1 6 I s % types described abo\e. (,,, a,--a maintenance fitter. aged fiJ, developed ,-e: raatitis aftet working on machines contaminated by formaldehyde dust. This affected only the hands ,.nd arms in the first place and he was removed from the oh and given work as a storekeeper following which the large percentage of time lost by a small number of men. Eighty per cent, of the total time lest was caused by five men (more than half of this was due to one man). Seventy-seven per cent, of the total number of cases of dermatitis lost no time and .oi.duion healed. While in the stores he was one day were successfully treated while continuing to work-- .l.-d-encndv handed a number of valves contaminated occasionally at the same job. During the last two i-|. urca formaldehyde powder and within a few hours years (1949-1950) only four men lost time and i .lud dcseloped a sensitization eczema affecting the ,,o. hands, forearms, axillae, scrotum, and groins. He ,,.i, taker off work altogether and only slowly responded between them accounted for less than 5% of the total time lost through dermatitis. i t e./mem extending over a period of weeks. On his ...urn :o work he complained that he felt an immediate igkng of his eyes and face even when he entered the ..v;ory tor a few moments as he did contrary to instruc - on one or two occasions. He was finally given Effects on Absorption.--The acute effects of formaldehyde vapour on the eyes and respiratory passages are w'ell known; they are frequently produced by vapour concentrations as low as 20 .i' a commissionaire in a laboratory building far to 30 p.p.m. Lower concentrations may result in i o ca from the factory itself and he has had no further watering of the eyes, irrjtation of the throat and :\e during the last few years. upper respiratory tract (Barnes and Speicher. 1942), The problem of permanent alternative work for but these symptoms often disappear after a short dcimr.titis cases presents difficulties, and Squire interval (10-30 minutes) as the worker gradually others (1950) have rightly stressed that each becomes accustomed to the vapour. The inhalation i. dnidtial case must be given serious consideration of high concentrations has been shown to produce iv'oh a decision is made one way or the other. It pulmonary oedema and haemorrhage but the h i' been found that most cases of dermatitis pungency of the vapour usually makes it impossible ;v . formaldehyde occurring in this group of to remain in atmospheres contaminated to such an Ties become sensitized to it so that they seem extent. The extensive literature on its toxicity is well nv liable to a skin eruption subsequently but a few summarized by theU.S. Public Health Service (1945), .'cn'. p an immunity or possibly take greater care but in spite of the vast number of investigations . cun ning to their work. This is in agreement with which have been undertaken there is a notable lack vhwartz (1945) but contrary to his opinion urea of information and Conformity of opinion on the >'.'i".nldehyde resins seem to be as potent a cause of possible chronic effects in man produced by the m.s as phenol formaldehyde preparations, repeated absorption of small quantities over a long i -. -y be due to the fact that in the cases described period of time. !'i\ the glues and resins were of that com- Fischer (1905) asserts that the inhalation of the >n which rapidly hardened on contact with gas even in small quantities is followed by bronchitis V n in and pneumonia but few other investigators agree I : e small factory, manufacturing urca and with this statement. A case is quoted by Lile '1910) "n ' 1 '.'rmaldehyds resins, glues, and moulding of a tuberculous patient who was kept in a room ' - the number of cases of dermatitis were saturated with formaldehyde gas for several weeks, .i-.wcly tew as can be seen in the accompany- during which time the patient actually gained H - ,, This factory employed an average of weight and his physical condition apparently s:-v. 150 and 250 men at any one time over a improved. These effects arc surprising even though \ of year-, but since the labour turnover was the actual atmospheric concentration of formal " i-di more individuals than the average number dehyde in the room is not known. The term v .'P-'wd to risk during each year. 'saturated" conveys very little except that the I table shows that the amount of time lost concentration was presumably high. It is possible . : tends ;<' diminish in spite of the niaikcd for men to work without cmbatrassn'civ. in i -. ' i production. An interesting feature is the atmosplieies contaminated with formaldehyde to an | 4* i * a ST i i j I i ! HEALTH PROBLEMS /V PLASTICS INDUSTRY 259 . reJ | 1 ori'. wiiy . ;.U10. Liter on ' with No. 5 other \tble. mhetic plastic ie with .nt salt -,es and . amides articles .sample. electrical _ variety Limine Burcical Pj with :tes that S its use pciority he form -eriments of the nanisms 'u rinvs educed ing skin Toplcy. as have odman. ds in a contain liters so .parately s ii.'> h:i\e Ji is by Table ! clinical Hat a OF 2J Mt.N EXPOSLH TO FORMALOEinoE AaI'OLR s No, of Weight w- Year* F mploved. si. lb- BloOd Suninurt of iRi' Rer^'t Pressure * of Chest Complete Blood Count Other Find.-*' 4* P .10 5 140 80 Normal 10 83 110 65 Normal Normal White cells 10.500 Dermatitis (lasted - % dj**--[-<* time Jos!) H 10 2 CO 65 Old healed focui right upper zone White cells 11.400 ~" 6`. ` 11 s no 70 Normal 71 10 2 120 70 Suggestion of basal bronchi* White cells I3,90u Clinical chronic emph^se^'i. ectasis. Old healed focus Changed his job, le" the factorv right upper zone. No shortly after evar'-rutiisn evidence of actum -M 6* 9 10 126 SO Normal 7) 9 11 no 70 White cells 4,100 Normal 1 __ M 11 10 <01 120 80 Normal Normal 1 *. 4J 18 7n 145 90 Normal Hb- 92% - 4' 'i :: 4<j iot 11 31 130 80 Normal 3 11 31 140 70 8 10 5 143 90 Normal White cells 13,250 ` White cells 12.600 Normal / __ *- :4 !-l 4' 91 12 51 120,70 Normal Normal - 6 7 <21 120,65 I Old healed focus left upper White cells 11,700 Dermatitis--no time lost. Chest zone. No evidence of radiograph two sears later j activitj showed no charge from his previous report 9 7 11 120 70 Calcified hilar glands Normal -- * 1 * i-J ;v 7 10 K 160 115 Cardiac enlargement--\en- Normal tricular hvpertrnphv. No pulmonarv disease Cardiac enlargemer..--confirmed Clinically. (Triple rhvthmi aortic 2nd-4 . Pulnonarv baits clear. Some eviderce of hvper* tensive retinitis. Lrine. albu* min+ -F 6 88 PO so Increased vascular shadows White cells 14,900 "Arthritis", left dr.. * and rntht ,. knee 51 10 2l 130 SO Normal Normal __ l` 'v 11 8 01 120 70 White cells 4,500 6 10 IP I5n S3 Cardiac enlargement e-'m* White cells 11.SO*.' sistent with h'rertenjiv<n. Increased vascular sha- down No pulmonar) disease Si 13 101 170,100 Cardiac e-il^gement \as* White cells I4.U>' cular shtdows ir.crca>ed, No pulmonarv diseave -- - . Tt 13 9 6 I 5 98 i 180,75 OM focus right *pc\. Shadow left are' No evidence of activn> i:o so Emph'*er*.a Fibrosis both 1 apices and upper zones. probabl' old infiltration. No evidence of actons R B-C. 4.860,000 Hb 88-... White cells 10.000 Normal Dermatitis mildlv . - two oc.i* stons. No time i.-M Chest radiograph one >,*: later--no change from pres, u> report Mild dermatitis time !ooi, Keratosis p.ilnu*. 44 6 10 120,80 ! Normal Normal 8 9 101 120 65 Slight increased t)jdowa. Normal lower rones -- _ [ t 'i 1 |l J I : I , 1 i jh VT .,il* .lie. CiC. CJ1 a. ,n a . in\] .1 he low * :Mic and i'i k'.e .inccs >!astic w hich Jjies rc ally v.ho \ion. vs:S :i l i be thi< ;>! j. ^,| >n* l\v \v iih :hi' bat ce a ..it I'V* i,i\e HEALTH PROBLEMS IN PLASTICS INDUSTRY 261 l?l. Mailette and von Hearn (1952) . [hat dioctyl phthalate administered intra- re.ilK in comparatively large doses proved . : animals, but no delayed effect or permanent . _. a .is noted in surviving animals. Tetrafluorcthylene (CF:=CF.,) s.ibstitution of four fluorine for the hydrogen ns of ethylene produces an unstable reactive gas . - n as tctrafluorethylene. This and its polyi'!/ed form have been discussed in a previous which describes the toxic effects of the . nur under certain exceptional conditions : ' :'i<. 1951). \h [ti\ I Methacrylate (CH: C [CH3] COOCH3) \lethy] methacrylate, B.P. 100C, is a colourless .. d with a sweetish, characteristic odour, n j< a mild irritant of the mucous membranes and - .. :V.v instances has been known to produce .. mantis. Spealman, Main, Haag, and Larson us- state that the instillation of three drops of - monomer into the eye of a rabbit produced - mediate irritation with inflammation and .derna within a few hours. Complete recovery .anred after three days. On the skin it produced ,, -.cry mild irritation which was fleeting in its .''.'Cis. The writers also describe the toxicity tre monomer when administered to various - - .:ic subcutaneously, intraperitoneally, orally . .: by inhalation, and pathological changes . c found in the livers and kidneys resembling o iesions produced by carbon tetrachloride. !.> interesting to note that changes were ..rJ in the lungs due to its irritant action - ,r> in some instances were apparently reversible - a- healing subsequently occurred, r.-; same investigators submitted 50 volunteers .tch tests with the result that about one-third nt total developed a mild erythema in 48 hours. t.t :0"o showed evidence of having developed .-'tivity to the monomer when tested ten days Pol>merited methyl methacrylate similarly produced no effects. I he toxicity of the monomer when absorbed by . p.'.r-.-.ntal animals has been described by win (1941) who also mentioned its irritant the mucous membranes when inhaled. His ^..merits show that when absorbed in toxic mimes methyl methacrylate causes an increasing 'weakness, decreased respiration, dyspnoea, - i.s of reflex activity ; the animals finally died * i.i as the result of respiratory failure. ' . ,t;v.opheric concentration of methyl metha- \ 'hould be maintained below 1,000 parts pci million if working conditions are to be regarded as satisfactory. Its odour can be detected at far lower concentrations. Cases of dermatitis due to handling this monomer are not common and the few that have occurred in the present group of factories have been of a mild nature, quickly responding to alternative work.. Case 6.--This man, aged 43, was engaged in making decorative plastic models. A great deal of the work was done with bare hands which involved fairly gross con tamination with the liquid monomer and compositions containing it. He developed interdigital eczema of both hands but failed to report the condition to the ambulance room for a matter of four or five weeks. When first seen he had a dry, scaling eczema between the fingers of both hands and a papular erythema of the right forearm. This gradually cleared with local treatment and alterna tive work. A few cases of dermatitis have been reported in dental mechanics using polymethacrylate and its monomer in the manufacture of dental prostheses. In such instances working conditions are often unsatisfactory so that it is very important to establish the real cause of the skirt eruption and patch tests may be of value in these cases. Dental mechanics may be exposed to other irritants than methyl methacrylate and in some instances the use of abrasives (e.g. pumice powder) may have been the cause of the skin eruption. Polymethyl Methacrylate Under certain circumstances methyl methacrylate can be converted into a solid polymer that constitutes the basis of many commercial preparations known under the trade names " perspex ", " lucite", plexiglas ", " diakon ", " kallodent ", etc. These commercial preparations vary in composition and may contain other chemicals besides the polymer. A brief history of the monomer together with a detailed description of the chemistry, the properties and some of the applications of the polymer have been given by Caress (1944). The final polymer is like many others compar atively inert, e.g. it is used in the manufacture of contact lenses, artificial teeth, splints, and surgical instruments. Wilson (1946) has quoted 25 patients who had extrapleural pneumolyses by means of methyl methacrylate plombage. According to him the material fulfills all the essential criteria of an ideal for plonibagc, and 1 it is non-irritating to the human body". For this operation the "methyl methacrylate was moulded into solid and hollow balls" so that it is obvious the writer means the polymerized form although he uses the term methyl methacrylate (the monomer) throughout his paper. i I -i i t ** it UCC 083982 ... . `t-~~ ' % i/s i->;: -t'-'-c ,.CC.- '.'O on n a day '.'roughly apphcaconform : Stands vmism of :lic same into its of these . designed stringent accidents ith this .'ns develiate peneng of this cie burned which they protective 1 smarting or blisters c for skin potassium ;eJ in polya laborand stated e material the job he "Him perhe felt his pin point S day the uigers felt nance room a hands as i 'vse were d.ic course making onicr in a ,:nng bat at work when he : ,cht foot, "ce toont a of the 1 tie blister . remained inch time .'.ttures is SvJally arded as HEALTH PROBLEMS IS PLASTICS INDUSTRY become dangerous under compara- a: circumstances It also stresses the no tan. c of taking a full history and paying , . , . I . - .mention in this mstar.ee to the chemistry rials involved. Ci/.!' If1.--This laboratory worker, aged 24, was ,i;,!:ng methyl a dichlorpropionate and spilled some the liq.id on to his left hard. He washed it ofTin the o.iul wa;. and thought no more of it since previous cvpcricnce had shown the chemical to be quite hatmless. \hout three to four hours later he felt some irritation `vnc.tih the watch strap on his left wrist and thinking it w.o chaf.rg his skin he transferred the watch to the other wri't. Two hours later he noticed irritation of the right The following morning when he reported to the .ci'l'iiUnce room there were erythematous areas on both ,0'i'. Tne>t were covered with tulle gras dressings. rite following day he was away from the district in .-f\,c ,if the fact that the areas had now blistered and he J.a rot report to the ambulance room again until the nevt day. By this time he had large blisters on the jiiicrioi surfaces of both wrists (Fig. 2). The one on the wrist measured 3 in. 2 in. } in. They were the fluid gently evacuated and the blistered skin ...i.i.'.cd to collapse. Subsequent dressings with tulle gras p-oduccd rapid healing. U if Fig. 2.--L*rj* bliitert on both wrist* following exposure to mcth>t at % dichlorpropionate. Methyl |J dichlorpropionate readily loses a molecule of HC1 to become the powerful vesicant methyl a chloracrylate. Cl Cl ' h--<!:--<!:--cooch, - ft rt H Cl A. c/ -f HCl iri cooch, This must have occurred on the skin beneath the wrist-watch strap through which the original substance had penetrated. . '--V,- V jt eruption from exposure to mcthvl % ehtorior>Ute. Effect of the Vapour on the Eyes.--The vapour of methyl chloracrylate is markedly irritant even in low concentrations (5 to 10 p.p.m.) so that symptoms of eye irritation with photophobia and Jachrymation occur at an early stage. These symptoms may disappear without treatment and if the worker remains in contaminated atmospheres he is very likely to develop a severe conjunctivitis often after a latent interval of a few hours. Case 11.--This man, aged 25, was employed in a laboratory where a bottle containing methyl a chlora crylate was accidentally broken on the floor. The laboratory was cleared but the patient proceeded to mop up the liquid with the assistance of one other colleague. He stated that afterwards he washed his hands thoroughly and had his eyes irrigated before continuing to work in the vicinity of the accident. Later that evening he developed the typical eye symptoms described above and the following morning he telephoned the medical depart ment to state that he could not open his eyelids. He was brought to the ambulance room anJ on examination was found to have a severe bilateral conjunctivitis with oedema of the eyelids and intense blepharospasm. Following prolonged irrigation which was continued in the ambulance he was transferred to hospital where he .11 .. t l ii : l UCC 083983 . HEALTH PROBLEMS IS PLASTICS IS VESTRY :65 the ''".V l4wC With I'lim wh'ch h nation he ` c.- c being c ngated for Mi-bveuentiy 'inch longer .ivJ 10 have .i# allowed cr, the eyes .-pual in the day he had .edema and - rapidly to . k. tncidenburn of the mil he was mptoms and he had been r ,! # f k $ a <iir.--There repeated Tooted the decided to had been Thirty-four ion by an ^ed below. H technical .monomer. up-. : I 11 cases d' 15 cases 5 cases no patient c examinaabnomul \esicam. it a plant .'ion scale t the only -uperficial -c was this nniendcd. ;ny of the tests that or that res and f ? --Fieial oedema after the patient *ai splashed with chloracrylie acid. His normal features arc shown for comparison. Polymethyl Chloracrylate N-, h..s been stated above methyl chloracrylate . s:: iv polymerized under certain circumstances to r 'd;.:. a material resembling "perspex'-. The prc'cncc of free monomer or decomposition ? under particular conditions is suggested by L. i,:wthat machining the polymer on a lathe has 4i-.cn o:V the typical odour of the monomer and in ... o cases has produced eye symptoms. Local ventilation is sufficient to remove this Chloracry lie Acid t '';ance resembling methyl chloracrylate in --. -ties is % chloracrylie acid, and experimental . I. of its effects is given in Appendix c. < :c.- This man, aged 22, was employed in the " . .. csterifying ethylene glycol with chloracrylie the contents of the flask suddenly splashed .we. He immediately irrigated himself with .: :c jubseqently with a dilute solution of potassium -"'v.! ..-mate before reporting to the ambulance room. 11" c'. - ration he was found to have first degree burns ...e and neck with a mild conjunctivitis of the ' r- Prolonged irrigation of the eye and the nf a bland cream to the face seemed to t considerable improvement but by the next day the patient's face had become oedematous (Fig. 3). He also had second degree burns of the interdigital areas of the left hand and on both forearms. The right eye was not inflamed but the cornea showed a central pin head opacity and he was admitted to hospital for further treatment. His condition improved sufficiently rapidly for him to be discharged within a few days. A fortnight after the accident he was seen by an ophthalmologist who reported as follows: " The cornea shows a near central pin head leucoma which has scarred the anterior epithelium and Bowmans membrane only. It has healed. Near it there are seven or eight minute staining specks on the surface of the anterior epithelium. This will heal without scarring." On his recommendation the patient continued to have treatment in the form of sulphacetamide drops three times daily for a furthei brief period. The burns on the hand and forearms were dressed daily until they had healed. The illustration of this patient's faee might well represent the acute effects of formaldehyde vapour with the possible exception that in the latter condition the blisters tend to be smaller and. more like ec/ematous vesicles. Laminated Plastics These are plastic materials made by impregnating layers of fabric or paper with resins which arc subsequently polymerized by heat and pressure. r^^'rV'iniiOTi -* iMttcr of i he emedics vommun 1 provide 'i disenses :se ; and of some pharmaven given os for the epeatedly >de were I haemaihere was could be the final ovate that w hich can o formal ist weight ieviously ipparently :s but one :n respon- I normally .however Jiften a ft being such as of methyl ated from example, .ihacryiate ve irritant ain other siic soda cry, lead ".npounds "doom or ' can also ubjecting an alkali, onditions nay have nroduced ethylene d!y high a use of 'ItrposCS essential HEALTH PROBLEMS IS PLASTICS INDUSTRY 267 toxicity to be given careful consideration. , , ;hvi uses in surgery have already been ... \ ` hir a few examples are given below of the which they may come into contact with food drink. Plastics for this purpose may be used in -ei. n: of to) cups, beakers, plates, trays, bowls and , the; utensils ; () tubes for conveying consumable ue.ds. e g. water, beer, etc.: (e) films for wrapping ; * i linings for food containers, refrigerators.conveyor viK and machines used in the manufacture of food. Ph-ties used for the above purposes therefore .nun Id ideally contain no toxic substance of any ;,nd although this may sometimes be difficult to , in practice. In all cases of doubt it is essential :n.<r the plastic and its ingredients should be -abiccted to most rigid physical, chemical, and -V. vological tests to ensure the absence of toxicity r. applications of this kind. SUMMARY Synthetic plastic materials are made from polyprized chemicals with the addition of various ,'ihe: compounds. !VI> mers can be divided into condensation and j.vuion. or thermoplastic and thermosetting types. The condensation polymers are typically reprewnted by a group of formaldehyde products. The effects of formaldehyde on the skin and after absorption are discussed. Clinical examples and .he incidence of dermatitis in one small factory are , i.oted The result of an investigation on workers nuking formaldehyde products is described to '.ipport the contention that formaldehyde has little r no chronic effects when repeatedly absorbed in 'null quantities. The nylon polymers are briefly mentioned, The pathological effects of some addition poly mers, their monomers and substances associated with their manufacture are discussed, including vl.ithene. polyvinyl chloride, polymethacrylate, ink polymethyl chloracrylate. x brief reference is made to laminated plastics. The importance of a full investigation of plastic m.iieruls likely to be used for certain purposes is ! .or. grateful to Dr. R. G. Heyes for his assistance . p . ally on the chemistry of the polymers : to Dr. M. \V, Goldblaii for toxicological reports : to Dr. J. W, Rammell and Dr. J. S. Gourlay for their ophthalmic report* : to Dr. C. H. Hilliard and Dr. V. Magee for their respective opinions on the results of the chest radiographs and blood examinations in the investigation on formaldehy de workers. References Anon (1946). 4*To\iCit> of Plexiglas." J. Amar. med. Alt., 131, 1103, Queries and Minor Notes - ^(1947). * Any Questions?". But. ted. J-. 1* 551. Bamber, O (1950) Practitioner, 164. 385 Birnti, E. C.. and Speieher. H, W. (1942). J. industr. Hyg,, 24, 10, Bull. J. P., Squire, J. R., and Topley, E. (194$). Lattet, 2, 213. Burness, A.* Hammond. A* and William*, E. G. (1946). Brit. Blast., IS, 2?4A. Caress, A. (1944). Endeavour, 3, 156. Crubkshank. C. N. D. (1948). British. Journal ofIndustrial Medicine. 5, 204. Deichmann, W. (194J). J. industr. H. ?-. 23. 343. Factory Department. Ministry of Labour and National Service (1943). Memorandum on the Prevention of Industrial Dermatitis. Form 331, H.M S O. Fairhall, L. T. (1949). Industrial Toxicology. Williams and Wilkins, Baltimore. Farquhar, J. W., and Lewis, I. C. (l94$>. Lancet, 2, 244. Fischer, M. H. (1905). J. exp. Med.. 6, 487. GoldbbU, M. W. (1943). British Journal of Industrial Medicine, 2, 183. Harris, D. K. (1951). Uncet, 2, 1005. Haxton. H. (1945). Brit, med. J., 1. 12. Homer, 5- (1950). Practitioner, 164. 234, Hunter, D-, Perry, K. M. A., and Evans, R. B. (1944). British Journal of Industrial Medicine. J, 227. Hutchison. R., and Hunter, D. (1949). Clinical Methods, 12Ui d. Cassell. London, Ingram. J. T. (1948). Brit. med. J.. 2. 18?. Jeremiah, B. S. (1950). PlaSt, reconstr. Sure., $, 252. Jones, A. ThclwaU (1946). "British Journal of Industrial Medicine, 3, 83. Judet. J., and Judet, R. (1950). J. Bone Jt Surg., 32B, 166. Lile, 5. (1910). J Amer. med. ASS.. 54, 554. Little, G. E. (1950). Selected Gowrnmenr Res. Reps., 7, 75. Mellette, F. S., and Haam, E. von 0952). Arch, industr. /Of., 6, 231. Mayers, M. R., and Silverburg, M. (19J6). Industr. BuH., S. 15, 324. McGuigan. H. (1914). J. Amer. med. .4<r. 62. 984. Newman. P. H,, and Scales, J, T. (1951). J. Bone Jt Surg33B, 392. Payne, M. H., (1950). In Modern practice in Dermatology, edited G. B. Miichelf-Heggt, p. 777. Boitcrworth. London, Ridley, F. (1948). Trans, ophthal. $oc.. U.K., 6S, 301. Ridley, H. (1952a). lancet. I. 118. ------ (1952b). Practitioner, 169. 362. Schilling, R. S, F., Roberts, M., and Goodman, N. (1950), Lancet, 1,293. Schwartz, L. (1945). J. invest. Derm., 6, 239. ,------ , Peck. S. M., and Dunn. J. . (1943). U, Publ. filth Rep., 58 899. ----, TuUpan, L . and Peck, S. M. (1947). Occupational Diseases of the Skin, 2nd cd. ximpton, London. Sfddon. H. J.. and Scales, J. T. (1949k Lancet. 1, 795. Sitcock. F. A. E. (2944). Brit, med. J . 2. 830. Spealman. C. R., Mam. R. J., Haag. H B., and Larson P, S. <1945i- lndustrf Med.. 14, 292. Squire, J. R., Cruickshank, C. N, D.. and Topley. E. (1950). Brit. med. Bull., 7. 28. Swallow, J. C. (1944). Endeavour. J, 26. U.S. Publ. With Service (1945). " Formaldehyde--Its Toxicity and Potential Dangers." P.H. Rep. Supplement No. 181, Wiglev. J. E. M.. and Fox. p. B. (1950). Practitioner, 165, 33. Wilson. D. A. (I46) Surg. Clin. ,V. Amer., 26. 1060. Yonkman. F. F.. Lehman, A- J,. Pfeiffer, C. C-. and Chase, H. F. (1941). J. Pharmacol72. 46. Zeislcr, E. P. (1940). J. Amer. med .4 r,. 114. 2540. appendix r.'i? following toxicological data were obtained from -Mrtimen'.* earned out at the Industrial Hygiene H.vejrch Laboratories of Imperial Chemical Industries (a) Dlnonyl Dioctyl Phthalates.--Each compound used separately ga\e the following results :-- Oral Administration.--No ill effects observed I ua 'L. t ,-ii" UCC 083985 ML.,