Since it appears to contain an higher percentage of lead acetate it may have to await the second part of the plan.

The common uses of commercial PCB would not normally lead to its release into the natural environment.

The attempt to find a correlation between the Impinger and the Bausch & Lomb Dust Counter lead to the conclusion that little correlation between the two instruments exists, particularly In regards to large particle size as well as in areas of high dust onoentratlona.

Specifically in birds, PCB can effect the calcium metabolism leading to egg shell imperfections which prevents proper _ hatch of the young

191i*th MEETING - BOARD OF OPERATORS Jul7 11, 1966 - Page $ LARGE EXPENSE REQUISITIONS APPROVED Chicago Factory (Continued) 7953 Repair and maintain Steam Trestle - Tarda & and Z $2,813,00 7951* Replace defective insulation on all steam lines leading from North wall to vessels and equipment - CM3 MNPT - Bldg, 6J0-B 1,132.00 7957 Repair #1 Inert Gas Generator - Bldg. 300 1,158.60 7961 General repairs during shutdown period July 5 through July 15 C&C Beta - Bldg. 500-501 ------N 7,083.20 . . 7997 Addition to Req. #1752 "Engineering and Research Follow-up foyn _ ) I ) JQulnacridone Synthesis"' - originally approved for $5,000.00/ CM3 Research - Bldg, 531-3 {V 25,750.00 Chicago Research 9I7 Cost to install seamless floor for Constant Temperature Room 920 Replacement upper piston and lower piston for 021-0106 KBrDie and Custom Fitting on Infra Red Spectrophotometer - Analytical Research $63.00 131.00 Cleveland Administrative 7535 Estimated outside service expense and rental expense for 1966 fiscal year closing for Sales Accounting, Auditing Dept, and Executive Acctg.

._____ ____ __ Lead..........................

The common uses of commercial PCB would not normally lead to its release into the natural environment.

However, PCB has a solvent action (similar to paint thinner) on the fats and oils of the skin and prolonged contact may lead to drying and chapping of the skin.

C3 would not normally lead to its release into the natural environment.

However, PCB has a solvent action (similar to paint thinner) on the fats and oils of the skin and prolonged contact may lead to drying and chapping of the skin.

. - Price 10/30/62 A - Dividend S686 Yield COMMON 7*- 7* *20.20 *2.5% POSITION: The compcny It a leading miner and processor of vermlcullte. whlchli used mainly as a building material.

hod "cxcewlvc" oi. bestos flb m In their lunpi, a condition that often leads to Mirieus long disease.

Elements of Industrial Toxicology short-term acute exposures only ) It is quite possible that actual long-term chronic exposures to a substance could prove highly toxic even though short-term exposure tests indicate a low order of toxicity Brown states that measurements of rela tively crude physical effects --such as body and organ weight changes, anatomical changes, and lethal results --are usually in volved m tests of toxicity To assess the subtle effects a chemical may have, consider ation must be given to measuring central nervous system effects during toxicity tesbng Animal expenment data are difficult to interpret and apply to human exposure Such data are valuable only as guides to be used by the industrial toxicologist in estimating the gross toxicity of a substance and as leads for further investigation Hygienic Air Quality Standards It is from a variety of sources --including animal experiments, laboratory studies on humans, plus field and m-plant investigations of exposures--that the two prevailing con cepts for expressing safe concentrations (threshold limit value and acceptable concen tration) have been taken The concept that there are concentrations of air contaminants to which nearly all workers may be repeatedly exposed without discom fort or ill effect is fundamental to the practice of industrial hygiene These levels of air contamination are used as guides in the evaluation of health hazards Threshold limit values The American Conference ofGovernmental Industrial Hygienists (ACCIH) adopts a list of threshold limit values (TLV) each year for more than 450 substances These TLV's are expressed as parts of vapor or gas per million parts of air by volume (ppm) at 25 C and 760 mm Hg pressure or as approximate milligrams of particulate per cubic meter of air (mg/cu m) Mineral dusts are expressed as millions of particles per cubic foot (mppcf) based on impinger sam ples counted by light field techniques (The index of exposure to asbestos and quartz can also be calculated on a mass per unit volume basis, i e ; mg/cu m --see Table 42-B ) Table 42-B lists the threshold limit values of air-bome contaminants for 1968 The preface of this TLV list states that nearly all workers may be repeatedly exposed to the level m this list without adverse affect Certain values m this list preceded by a capi tal "C" should not be exceeded The basis for the TLV's may be reasonable freedom from irritation, narcosis, nuisance, or impair ment of health Some substances have the designation "skin " This refers to a poten tial contribution to the overall exposure by absorption through the skin or mucous mem brane A TLV of 15 mg/cu m or 50 mppcf is recom mended for inert or nuisance particulates which are not listed m the table When extremes of temperature or pressure are encountered, the TLV values should be adjusted to take into account the added stress The preface to the TLV list further states that these limits are intended for use in the field of industrial hygiene and should be in terpreted and applied only by persons trained in this field It emphasizes that they are not intended for use or for modification for use 1 As a relative index of toxicity by making a ratio of two limits, 2 In the evaluation or control of community air pollution or air pollution nuisances, 3 In estimating the toxic potential of con tinuous uninterrupted exposures, and 4 As proof or disproof of an existing disease or physical condition As stated m Appendix C to the list of TLV's, the test factors to be used for assigning limit ing "C" values may be used to determine permissible excursions for the time-weighted average TLVs Acceptable concentrations The American Standards Institute publishes the Z37 senes of Acceptable Concentrations (AC) for a number of substances (See Fig 42-2, "The Meaning of Acceptable Concen trations '') The ASI Z37 Committee has developed a number of innovations in concept In the past, a standard was conceived as a single limit, threshold, or a boundary between what is not and what is healthful But there is no such single boundary, the pattern of exposure in space and time may be variable There- 1306

"Can you tell me a simple concerned, a leading toxicolo with volunteer prisoners, wno strength of eggshells and even student's test is sufficient to gist declared Tuesday at the were injected with amounts of tually reduced reproduction. measure'relevance?"

In addition, beryllium, cobalt, manganese, r.i:- titanium, and vanadium were determined by the quantitative spectrographic methods; lead wa; determined by the L'SPHS dithlzone method: and copper, iron, magnesium, and zinc were de:t."