This report is submitted in response to a Commission staff request, and the events leading to its submission are known to the Commission.

Ronk read a prepared but as yet unavailable paper which reviewed the events leading to the proposed regulations to govern the use of PVC plastics for food contact applications.

As for 1975, his views were reported in the -lead of this article.

Hart also cited new research data "which would lead one to believe that the human health hazard associated with PCBs has been substantially underestimated."

WATER PCB-SD0000043071 1663 1 THE COURT: I'm not sure what you're leading 2 up to. 3 MR.

magnesite MgCO3 calcite CaCO3 dolomite CaMg The asbestos minerals given in Table 2 consist of certain varieties of the serpentine and amphibole groups Since the amphiboles do not exhibit intense thermal transitions distinguishable from talc DTA is not applicable for the detection of these minerals at low levels in talc However using the scanning technique of ray diffractometry we have been able to detect amphibole at less than 0.5 by weight in a talc matrix By this method the individual amphibole species present cannot be determined TABLE 2 ASBESTOS MINERALS Group Ideal formula Serpentine group chrysotile Amphibole group tremolite actinolite anthophyllite amosite crocidolite MgSi O5 MgsSigO22 C22 ,Si,O z MgSiO22 Mg Si O Na FFee Si,O z The serpentine minerals are related structurally both to the kaolinite minerals and to the chlorites This coupled with the variable chemical composition of the serpentines leads to great difficulty in their detection in trace amounts by ray diffractometry A sensitive and reliable technique was sought for the detection of small quantities of chrysotile asbestos in talc Thermograms of the serpentine minerals show a dehydroxylation endotherm at approximately 650 followed with very little intermediate phase by an exotherm at 820 associated with the formation of forsterite These intense thermal transitions suggest DTA as a method for detecting chrysotile in a tale matrix Mineral impurities normally found in pharmaceutical grade talc do not interfere 200 EXPERIMENTAL A Robert L.

The residual gas consists of up to 90% vinylchlorlde (6) and often leads to leaden tiredness and short-lasting disorientation In the employees. 3.

Those criteria allow one to assess the probability that electrostatic discharges can occur which, in turn, can lead to the fire and/or explosion hazard.

By this time, it had been established that the inhalation of excessive quantities of asbestos fiber in occupational settings could lead to increased risk of respiratory disease and certain types of cancer among industrial workers.

ward ocean pollution at meetings leading to the coming United Nations-sponsored Law of the Sea Conference, says John Hussey, an ex pert on the Senate Commerce Committee staff.

- because frequent replacement of relatively small quantiti will lead to disposal rather than recovery, or T . - because a large number of snail units widely dispersed .* will make collection extremely difficult, or - because accidental leakage will cause imminent danger to human health. 5.

A gas sam ple tube leads from each metering device to a central gas chromatograph.

Research may lead to economically g more feasible methods t{/ceteKcticm%f]^Uution control pro grams, and maintenance of adequate surveillance over all possible pollu tion sources. .

Leading off was a very complete slide presentation, including some excellent photography of an explosion and fire at the Primex 90 mm pounds per year PVC Plant in Pueblo, Mexico.

The lead recovery process used for rebuilding diaphragm cells involves some organic matter which burns off in the lead melting furnace.