I expect to spend the greater part of my. scientific life investigating the problem of heavy me,tal poisoning with special reference to lead* . ** .

Russell asks for additional information on the amount of Tetraethyl Lead remaining in gasoline after evaporation.

Kille of the insurance com pany asked me whomhe should contact in our organiza tion in the event that his people felt there was a joint legal responsibility between his company and ours in the death of Hubbard* because of the fact that we introduced the tetraethyl lead into the tank at Tampa.

There was no evidence of the presence of any tetraethyl lead or triethyl lead compound.

Flammable and Combustible Liquids Forced ventilation may be required in many cases where repair work is to be done inside a tank Where fumes develop from welding or other repair work, mechanical air movers should be used or the workmen should wear fresh air hose masks On a large tank, a door sheet or sheets may be removed for ventila tion after the tank has been made gas free The opening also can be used to expedite removal of sediment and to increase illumina tion If a tank has been closed for some time, there may he a deficiencv of oxygen due to rusting (oxidation) of the metal of the tank In that case, no one should enter the tank without a supplied air mask or, for a relatively brief stay, a self-contained or self-generating breathing apparatus Cleaning aboveground tanks Here m step-by-step form is a summary of a typical procedure for cleaning tanks that have contained flammable or combustible liquids 1 Remove all sources of ignition (matches, open flames, smoking, gas engines, weld ing, exposed electrical wiring and equip ment) from the vicinity of the tank 2 Empty the tank by pumping, draining, and floating tank contents with water, introducing the water through fixed tank connections 3 Disconnect and blank all product, steam smothering, foam, and similar lines Do not rely on valves 4 Open all manholes and allow the tank to air thoroughly Ventilate or steam the tank for the number of hours required by its size If steam is used, cool and ventilate afterward 5 Have available the required personal pro tective equipment fresh air hose masks, approved flashlights, safety belts and life lines, rubber boots and gloves 6 If light is needed, use only flashlights or electric lanterns approved for combusti ble atmospheres by Underwriters' Lab oratories, Inc 7 Test for vapor content with a combustible gas indicator For entering the tank be fore it tests vapor-free, wear a fresh air hose mask, air supply tanks, and safety belt and lifeline if the tank atmosphere contains more than the maximum accept able concentration of the vapor Have ample help available outside for the number of men inside 8 If a storage tank has contained leaded gasoline subsequent to its last thorough cleaning, follow instructions of suppliers of tetraethyl lead 9 Bond steam, lines and water wash nozzles to the tank 10 Wash sludge, sediment, and scale from the tank through the dram or remove it with a pump Flush out well and over flow the tank with water if necessary 11 Make a gas test and, if the tank is found vapor-free, check conditions inside the tank before issuing an OK for the work Otherwise, clean and ventilate further as required 12 Continue ventilation for duration of the work m the tank, and make periodic tests for the presence of gases or vapors as the work progresses Ventilation by air instead of steaming is used more widely where deposits of iron sulfide are not present and where a source of power supply for mechanical air removers is available Special precautions are required for the servicing of tanks which contain pyro phoric iron sulfide (See the API accident prevention manual.

Tetraethyl lead--see Lead.

Skin irritations were on the rise from the use of artifi cial resins, and lead poisoning was becoming common from the use of tetraethyl lead in gasoline.

(The somewhat unusual situation in which the head of a department in a medical school was also the medical director of an industrial organization, came about many years ago, when Ethyl Corporation was organized by reason of the fact that I had carried out most of the experimental and clinical work on tetraethyl lead arid was, at that time, about the only physician in the country who knew anything about the problem.)

1191 Substance 2-diffuoroethane 1, 1, 2, 2-Tetrechloroethane--Skin Tetrachloroethylene, see Perchloroethytene Tetrachloromethane, see Carbon tetrachloride Tetrachloronaphthalene--Skin Tetraethyl lead (as Pb)--Skin Tetrahydrofuran Tetremethyl lead (as Pb)--Skin Tetramethyl succinomtnle--Skin Tetranitromethane Tetryl (2, 4, 6-trmitrophenyf- melhylmtramlne)--Skin Thallium (soluble compounds)-- Skin (as Ti) Thiram Tin (Inorganic compounds, except SnH and SnO>) as Sn Tin (organic compounds)--Skin (as Sn) Tin oxide Titanium dioxide * Toluene (toluol) C Toluene-2, 4-dilsocyanate o-Tolmdine Toxaphene, see Chlorinated camphene Tnbutyl phosphate 1, 1, 1-Trichforoethane, see Methyl chloroform 1,1, 2-Tnchloroethane--Skin Trichloroethylene Trichloromethane, see Chloroform Trichioronaphthalene--Skin 1, 2, 3-Trichloropropane 1,1, 2-Trlchloro 1, 2, 2-tnfluoroelhane Triethylamine Trifluoromonobromomethane Trlmethyl benzene 2, 4, 6-Trtmtrophenol, see Picric acid 2, 4, 6-Trinitrophenylmethylmtramlne, see Tetryl Trin itrotoluene--Skin Trlorthocresyl phosphate Trlpheny!

Kehoe, University; of Cincinnati, College of;Medicine, Cincinnati;, OHIO, U3A Dear Bob, I regret to advise yon that we recently had a tank cleaning incident in this country, the first since 1945* This resulted in five cases of Tetraethyl Lead intoxication, but I am glad to say that on this occasion there were no death Inclosed is a copy of a report prepared by Dr.

Roush his calculations showing that considerably less tetraethyl lead will evaporate from the Vitol solution than from gasoline.

Furthermore, there were no de layed evidences of injury as a consequence of the treatments with tetraethyl lead, ethylene dihroaide, etc.

March 7, 3.940 Dr* B# Hurtado Colombian Petroleum Cotap any Cucuta# Box 100 Colombia,* South America Dear Doctor Hurtado* I was very sorry to have missed you on the occasion of your recent visit to Cincinnati# for I should have been pleased to talk with you about various phases of our work* I am sure you obtained all of the practically useful Information from Dr# Sanders however* so that I trust your trip to Cincinnati served your purpose# I believe you received most of the reprints of our work which were available* On the other hand there was a series of articles which had been translated into Spanish# which# X believe# will be useful to you in that language# Accordingly I have sent you,under separate cover* copies of these translations* If you should find that you require additional copies of these translations# please do not hesitate to lot me know for I had these articles translated primarily for the use of medical men who are concerned with this problem* I should appreciate it if you would drop me a note from time to time# letting me know of your progress and specially of any difficulties which may occur# Our experience in other countries in connection with the occurrence of difficulties may well be of some value to you if such trouble should arise# In any case I try to keep in touch with what occurs in various parts of the world in this connection# It is possible that your attention was not called with emphasis to the rather serious hazards which may be associated with the cleaning out of storage tanks which have been used over a considerable period of time for the blending and storage of leaded gasoline# We have had a series of accidents In this country which have been the result of failure to carry out the regulations which we have prescribed in connection with this work* It seems that from time to time a group of workmen will Insist upon entering these tanks for the purpose of cleaning without being supplied with the necessary protective clothing# and especially with an airline hose mask# Under certain unusual oiroumatmoos it may happen that concentrated Ethyl Fluid Introduced into the gasoline in too rapid a streara,may sink to the bottom of such tanks and lie there over a period of months or years in the sludge# This happens, of course, only if there is a water bottom in the tank# Subsequently when men enter such a tank to clean it, they may have serious contact with concentrated Ethyl Fluid, and they may also be exposed to relatively concentrated vapors of tetraethyl lead# All of these things can be avoided by proper attention to the regulations which we have devised and which are given in detail in the booklet of regulations which you have# I call your attention to this point as being the one thing which is moat* likely to result in serious difficulties, in order that you may warn your people against this danger and urge upon them the necessity of proper precautionary measures* Cordially yours.

As I told him, and without supporting data at this time, this manganese compound is quite toxic, its toxicity being comparable to that of other rn etallo-organic compounds, including tetraethyl lead.

Tetraethyl lead exhibits the greatest stabilizing effect of many compounds tested but leads to a slight precip itate.