Document yXa1B0Lo3rB5xDR7QQ9wm4kn

A r f' c ( ctV c.c. G.E. Moore DVNU/US 16th Juno, 1967 Moenrs. Titanine Ltd., Titonine Works, Sheaveshill Avenue, London N.W. 9 For the Attention of Mr. OilHeon Dear Sirs, . With reference to our recent disousslon over the telephone concerning the possible hazard in spraying airoraft with your uorylio luoquer, whioli oontaine our Aroolor 1242, I have made the foiloving oaloulations from the data given to me. iLompoeitlon of Aorylic henIn Lacquer ' 29 parte Aroolor 1242 100 parts Aorylic heein ay cjQ porta 1 iguent 173 parte Coouoeltlon of Spray Applied at 18, eolidsr asoumo Aroclor 1242 ia not included in solldc* Ilenoe composition of epray ie- 3 parte Aroolor 1242 12 parte Acrylic rosin 6 parte Pigu*nt 82 parts Thinners ) ) 18 Rate of Application 2 guns for l hours each at 10 fluid 0-./minute i.e. total quantity applied 1600 fluid ozs. . DSW 020338 STLCOPCB4008267 (tUantlty of Aroolor 1242 At 5> the 1600 fluid ozs. oontain 54 o.o. Aroolor 1242. Thia lo equivalent to 54 x 28,Q00Kgr:B l,652,000ngro. Hence If all the Aroolor 1242 is volatilised (and this in impossible) the voluae of air necessary to dilute to 1 mgnn./m* l.e. the maximum permissible for oontinued breathing (8 hours per day on each and every day during working life!) is 1,652,000 m* or 5^,320,000 cub. ft. during the spraying period of 1& hours. Dimensions of Hangar If we take 150' x 150' x 40' as the minimum neoesBary to house the airoreft and provide reasonable working acoeae we huve a volune of ^00,000 oub. ft., but the actual volume of your hangar is probably muoh greater* Air Changes necessary to ivo 1 mvra/n^ 58.520.00CJ 900,000 65 in ljt hours 44 ohangee/hour. You can estimate by this approach, knowing the size of your hanger and tho oapacity of tlie ventilation eye tea, the numbers of changes that would apply in your coee, but as 1 have emphasised above, tills is to give the safe working oonoertration for oontinued worklor. For oooaoion&l spraying periods, suoh as we have oonsiderod above, the oonoertration oould go ouch higher for safely, but the workers asy objeot to the smell et oonoentratlons of 1 port/ million of air or over. So far we have oonsiderod the spray only from the Aroolor viewpoint, but, there is about 27 times as ouch thinnera to bs reckoned with, and these arc not very pleasant things to breathe. As regards the risk of inhaling Aroolor and solvent mists, 1 would think it desirable for those carrying out the spraying to use a nose and mouth .respirator with a oannieter suitable for absorbing organic vapours, or with a remote breathing tube oonneotlng to the outer air, but tho wearing of these may well raise the accident risk, end you aust balance one against the other. Moreover, as you have had no trouble vith sprays containing phosphoric acid, It le probably unlikely that liquid droplets of the aoryllo spray are going DSW 020339 STLCOPCB4008268 to cauoe ouch trouble. Please write to ow afcoin if there uro other points to bo considered. Yours fai tiJ'ully, D.V.K. HAkDY v OSH 020340 STLCOPCB4008269