Document pBxmRJBXyBR5vbY47eLgx2Q6k

PLASTICIZERS Because all plasticizer uses of PCB were regarded as essentially "open" to the environment it was impossible to preventsthe leaching and volatilization of PCBs. Consequently, Monsanto realized the untenable nature of these applications when the allegations concerning environmental contamination by PCBs were confirmed. We discontinued all sales of PCBs to domestic U.S. customers for plasticizer applications one year ago. i The type of application affected by the market withdrawal of PCBs were: Surface coatings; sealants; adhesives; printing inks; miscellaneous such as pesticide carriers, wax modifiers, catalyst carriers, etc. Starting in the 1940's industrial (maintenance) coatings were the main outlet for PCBs in the surface coating industry. PCBs were chosen over other plasticizer candidates because of their outstanding chemical and moisture resistance. For example, PCB-plasticized coatings have enabled industrial equipment to withstand attack in strongly corrosive atmospheres. OS\N 333849 STLCOPCB4080426 PLASTICIZERS - Page 2 In the 1950's, synthetic elastomer sealants began to replace traditional putty-type caulks and sealants. One of the major synthetic elastomers was polysulfide. PCBs were used in these sealants to give excellent adhesion to a variety of substrates, moisture and chemical resistance, and for reducing hazards with the catalyst systems employed in curing the elastomer. These PCB plasticizer polysulfide sealants were essential to meet the caulking and sealant needs of modern buildings and construction. Our discontinuation of PCB sales to the sealant industry has created a very real technical problem for them. Totally satisfactory alternates do not yet seem to be available. In the 1940's and 1950's, PCBs were used in adhesives to impart tackiness and because they exhibited excellent bonding power to many substrates. They also exhibited greater compatibility with a wide variety of the many resins used by the adhesives industry. In a word their versatility led to their wide usage. They were also chemical and moisture resistant and resistant to heat and oxidation. In the mid-1960's, however, a drop in their usage had already become evident. DSW 333850 STLCOPCB4080427 PLASTICIZERS - Page 3 Adhesive suppliers were increasingly called upon to supply FDA-approved, low-odor products. PCBs did not satisfy these developing market needs. Even before the environmental pollution situation arose we were engaged in developing and supplying new plasticizers to meet the needs of the adhesive market. The new products are not PCB-based. Monsanto's Aroclor Plasticizer Bulletin 0/PL-306 may appear to the layman to indicate that PCB found its way deliberately into almost every product produced in the nation. Applications such as dedusting agents, pesticide carriers, catalyst carriers, impregnating compounds, etc., are listed as Aroclor and have been so publicized by the press coverage given to PCBs. The fact is, however, that very few of these uses accounted for more than 4 or 5 drums of PCB per year. In 1969 an exhaustive survey of our PCB customers was made to determine exactly where these products were being used. An example from the survey may be of interest. We found only three customers in 1969 using any PCB in pesticide formulations. Total consumption was between 5 to 10,000 pounds PCB per year. DSW 333851 STLCOPCB4080428 PLASTICIZERS - Page 4 This application was developed by USDA scientists at Beltsville, Maryland, in the early 1950's. The aim was to incorporate "chlorinated polyphenyls" into lindane and possibly chlordane to improve the residual effects. To Monsanto's knowledge there was never any recommendation by anyone for their use on food or other crops. The principal application was to spray metal or painted surfaces to increase the effectiveness of the active pesticide against flies, ants, roaches, etc. In April, 1970, we wrote to Dr. Hayes, Director, Pesticide Regulations Division, USDA, suggesting that no approvals should be given to pesticide formulations containing PCB. All applications of a "miscellaneous" category uncovered during our 1969 survey of customers buying PCBs through the Plasticizer Business Group of Monsanto were included in the sales ban put into effect in August, 1970. PCB APPLICATIONS IN PLASTICIZERS - USA ONLY (PRIOR TO DISCONTINUATION) Surface Coatings Sealants Adhesives Miscellaneous 57% 20% 17% 6% DSW 333852 STLCOPCB4080429 PLASTICIZERS - Page 5 The use of PCB as a solvent for the encapsulation of dyes for carbonless carbon paper began in the 1960's. Factors which influenced the selection of PCB were: dye solubility; UV light stability; intensity of color development; speed of color development; moisture resistance; and non-reactive with dyestuffs. In spite of research efforts for the past ten years it has only been in the past two years that the promise of satisfactory alternates have been brought to light. Since 1970 we have been supplying non-PCB alternates to this industry. The research for even better replacements continues but none of these is based on PCB. 0S\N 333853 STLCOPCB4080430