Document byyJ9Qy4Oox14wBxq2rMZGrOO

FILE NAME: RT Vanderbilt (RTV) DATE: 1983 Nov 11 DOC#: RTV201 DOCUMENT DESCRIPTION: McCrone Associates Letter to RTV RE Talc Samples 2048 |9 - Letter From McCronc Research Associated L td. to LW . Owens, Amtale Association dated November I I , 1983 (Pages 2048-20511 "V rt^ O N C ` m ew s, a rts ic c u t . t.ooo " ' = riu,,.0,t. i.iM.M* t,i m . m m Tfi-LCn*** LHB* H7 /ft \A \ Ccmlocl m t i 'c h *clinline hftTfjmvnu M itfoitpr. X `f*r tfffriiiien, jir, D^ens Amtslc Association 1 Queens Avenue Dale Street Liverpool L2 4TI Ltd. H A'ovenber 1983 Dear f-- . Ovens; He refer to ttie letter received from R.T, Vanderbilt Cooptny Inc., dated October, 31, 1983, relating to the analysis of the 3X Talc carried out by u* for Expandite Ltd, in London (reference our Report* HE 903 and HE 907AI. e apoiogire for the error in the reports, which stated that an esti mated quantity in excess of 90S tremollte asbastoa was found in the 3X Talc. This should have ream In exceas of 90% treoolita. The actual treoollte asbestos content is between 30% and 40%, Since receipt of the letter f r o g R.T. Vanderbilt Company Ice., v e re-examined the 3X Talc samples submitted for analysis hv Expandlte Ltd., trTKg"optical microscopy and K-ray diffraction a n a l y s i s . T h a reiults of t m s re-analysis, with estimated quantities, are as follows) Antigorite<2% Calcito <2% Quarte <2% Talc <4% Tremollte 550% The antigorite was identified by X-ray diffraction analysis. The results of tha re-examination agree with those reported to Expandite Ltd. in Report HE 907, dated 21 September 19B3. Tha high per centage of tremolite in the 3X Talc has also been confirmed. An additional study of the Talc by optical microscopy had shown that the troolite occurs as prisms, needles and fibres. Respirable fibres are defined as those particles having a length greater than 5pm, a width leas than 3pm. with an aspect ratio of greater than 3*1. Within the submitted sample* of 3X Talc, between 30% anq ant nf.Hi particles conformed to the regulatory definition of respirable fibres. It is Known tnat fine fibres become airborne much more readily than large particle*, especially if the large particles are piety. In order to assess the amount of fibres that would be encountered in an airborne cloud Dfieton; 04, J, ft. Mrt~ O . 4Hcn% Ml J, ftmiie Mi*. S* Ma* teaO , 1IC 2 0 49 Hr. K.H. Owens (continued) 2 of IX Talc, about 10 grams of the powder was placed into a polythene bag, 12* x 8", and this was gently shaken. .A sample of the airborne dust generated inside the bag was collected on a membrane filter, through which air was drawn at 2 litres per minute. This dust waj evaluated by optical microscopy and it was found that the percentage of respirable fibres in the airborne dust van between 70s end SOI. This indicates that work on the Talc powder enhances the percentage of respirable asbestos in an airborne cloud. One of the recommendations of the U.K. Advisory Consslttee on Asbestos, 1979, is that, wherever possible, a substitute for asbestos should be used. It 1* known that there are many sources of fibre-free Talc and,to comply with this recommendation,one of these should be used in place of Tal c which is significantly contaminated wit h asbestos. The U.K. health and Safety at Work etc. Act, 1974, places the respon sibility on all manufacturer* and suppliers to warn ussr* of potentially damaging materials in their products, and failure to do s o is to contra vene this Act, Individual products containing asbestos in the U.K. are voluntarily labelled as such by the manufacturers, even when the product is well b o nd e d wit h virtually no potential for the asbestos fibres to become airborne. Your method of trensport of the 3X Tele containing loose asbestos in such concentrations, in paper sacks, is contravening all British regulation*. If y o u have further enquiries regarding the suitability of this material for use in British industry, please contact either ourselves, the Asbesto* Information Centre or the U.K. Health and Safety Executive. Yours sincerely for H R A Ltd cc:Dr. R.C. Moore Expandite Ltd. 1-9 C hare Road London K W 1 0 6 PS H.S. Vanderbilt H.T, Vanderbilt Co-Inc 30 Winfield Street Norwalk, Connecticut ' 06055, USA Hr, Ian Halter C. HeCrone Aaaoc. Inc. 2820 south Michigan Avenue Chicago, Illinois 60616, USA Hr*. Luc y 8. HeCrone Senior Research Scientist Halter C. HeCrone Assoc. Inc, 2820 South Michigan AYenus Chicago, Illinois $0616, USA