Document DRNBdzRm0ZKBg8raBjBxQmzN

1 July, 1969 Mr J B Lynch Department of Health* Education and Welfare Public Health Servioe 1014 Broadway Cincinnati Ohio 45202 Dear Mr Lynch* Thank yon for your letter of lone 13*1969* and for the oopy of your Paper entitled 'Brake Lining Decomposition Products' The last sentence in my summary of your conclusions was taken from the draft report which yon sent me in January* 1968* but I see that your views have now changed* I suggest* therefore* that the final part of my reference to your work should read as follows: "At lower bulk lining temperatures within the normal operating range* the binder behind the surface remains intaot* However* the spot temperature at the point of contaot between the lining and the drum may be higher than the decomposition temperature of asbestos* The decomposition product* therefore* includes not free asbestos fibres but a different mineral* resulting from thermal metamorphosis*" I hope that this reference to your work is now acceptable to you and unless I hear from you to the contrary I will publish it in this form* Yours sincerely. D E Hiokish Industrial Hygiene Specialist 8850 HFM - 005786 1/168 8006 1200