Document BRNXbVYQNJjgv089egexjNmGw

(Jx&o-crfv~ 6 9 0 1 / W E S T 6 S Tm S TREET CH I CA GO February >, Iyl, Dr. Robert a. Kehoe Kettering Laboratory Univ. or Cincinnati Cincinnati, Ohio Dear Dr. Kehoe: I greatly appreciate your letter of.January 26th. Vthile I appreciate your feelings tnat it would be desirable to hold the lead content of dentifrices to a minimum this may not be possible. Any lead-bearing tube apparently introduces some lead into a contained den tifrice and the amount of lead in the den tifrice appears to approximate 50 to 100 p.p.m. of those dentifrices shewing the low est absorption and much greater quantities in some other dentifrices. I quite appreciate your point that it is impossible to establish a safe lead toler ance for tooth paste. Can you on the other hand say approximately how high the lead con tent would have to go before you would feel that it v/as definitely dangerous? Very truly yours, THR :M(j Technical Director