. -- 0.2 -- -- |133S-092| (1966)___ Tetraethyl lead 179492], _2 1 Sullur dioxide 17446095] (13661............... 2 5.2 5 13 as Pb--Shin (tsee).. .

It seemed likely then that I should be in England or en route at the time of the Conference, and since I could neither be preeeat nor pass upon the material that might be presented on tetraethyl lead or (by any of our staff) on the carcinogenicity of petroleum fractions, I could not enter heartily into the suggestion that these matters be dealt with in the conference.

If vapors involved, apply appro 1000,, 250 mppcf priate TLV 500 A& 10 mg/mr $ SiOg +5 $ Resp. ree SiC>2*+2 (alternative mass formula) Respirable free SiOg as defined by: Areodynamic Diameter Minimal (uiit density sphere) % micra < 2.0 Collected 90 2.5 75 3.5 50 5.0 25 10.0 0 Stoddard solvent Tetraethyl lead Tetramethyl lead 500. 0.075 0.075 200 Downward revision ?

Obviously when such a tank is cleaned, the workmen may have serious exposure to liquid lead compounds in addition to tho dusty decomposition products of tetraethyl load# I do not intend to discuss all of the possibilities or suppositions in this letter* but no hope to have tho facts available as the result of our observations here and we should then be able to do what Is necessary to solve this problem even if it seems taking the whole matter of tank cleaning under our supervision essentially# It is quite apparent here that the mechanism of putting into effect tho instructions which we have issued on this subject has been unsatisfactory.

If vapors involved, apply appro 1000,, 250 mppcf priate TLV 500 A& 10 mg/mr $ SiOg +5 $ Resp. ree SiC>2*+2 (alternative mass formula) Respirable free SiOg as defined by: Areodynamic Diameter Minimal (uiit density sphere) % micra < 2.0 Collected 90 2.5 75 3.5 50 5.0 25 10.0 0 Stoddard solvent Tetraethyl lead Tetramethyl lead 500. 0.075 0.075 200 Downward revision ?

Kehoe, I enclose copy of a letter together with a summary of results of inhalation experiments that were carried' out at Porton by Miss Cremer on TetraEthyl Lead and TetraMethyl Lead in rats.

Med, lt|, 1^-191^^May7 i9^9} The author cites the cases of the radium dial painters, the develop ment of tetraethyl lead, the construction of the Holland Tunnel, and the work on refrigerants as examples of the application of research to indus trial hygiene problems.

According to the chemist* the fluid was described as fifty per cent tetraethyl lead in a carrier to which dye had been added.

Med, 18, 159-191 (May, 19$9) - The author cites the cases of the radium dial painters, the develop ment of tetraethyl lead, the construction of the Holland Tunnel, and the work on refrigerants as examples of the application of research to indus trial hygiene problems.

Sayers 18, 169-191 "(May, 191*9) The author cites the cases of the radium dial painters, the develop ment of tetraethyl lead, the construction of the Holland Tunnel, and the work on refrigerants as examples of the application of research to indus trial hygiene problems.

Shore are a great number and- variety of- physiologi cal problems in industry which involve- the health of employees and public. .hat an importance such problems can assume is illustrated by the history of tetraethyl lead Which is not yet a closed problem).

I am very glad to hear from you again and I am Interested in knowing that you are getting Into some work on lead* I gladly comply with ^our request to send along some reprints, and I am pending you one series of six articles bound together on "The llomal Absorption and Excretion of Dead", of which my supply is almost entirely ex hausted* I think it will be useful for you to have a copy of this and so I am stretching a point to supply you with a somewhat battered copy* However it is the boat I can do# We have carried on our work here beyond the point represented in these reprints, but I have not had either the time or opportunity to put together and publish our recent results# However you will find of considerable interest, I believe, the reprint on "An Appraisal of the Lead Hasards Associated with the Distribution and Use of Gasoline Containing Tetraethyl Lead* Part II - The Occupational Lead Exposure of Filling Station Attendants and Garage Mechanics", because, so far as I know, it gives the details of the first adequate metabolic studies on lead in the normal human subject* We are carrying this experimentation further In some studies of lead in gestin on human subjects.

Our tetraethyl lead earnings are on target as our marketing agreements maximize earnings and cash flow in this declining market.

(Tetraethyl lead) (03115)4 Pb, load tetraethyl.

The pump m- had, however, previously been used to pump tetraethyl lead, the pumping hav ing been done by hand.