PCBs AND ASSOCIATED AROMATICS 853
oil used to control dust in Missouri horse arenas. When the
waste oil storage tank was examined, it was found to contain
300 ppm TCDD.
July 1971: A Monsanto PCB bulletin [Monsanto, 1971]
was issued in July 1971 entitled ‘Handling, Waste Control
and Disposal of PCBs’. The document was “ Produced and
distributed as a service to industry by Monsanto ”. It was
pointed out that Pydraul ® , a fire resistant hydraulic fluid, was
no longer manufactured with PCBs but other products had a
place in continued applications provided that common sense
and good maintenance procedure were used towards elimi-
nating any threat to the environment from PCBs.
Monsanto offered nine guidelines to prevent the escape
of PCBs into the environment. In conclusion, the disposal
of solids was suggested in a properly operated landfill not
located near any water system.
The Monsanto position was explained in a series of
points which included Monsanto’s recommendation that
PCB contaminated solids could be buried as a satisfac-
tory disposal option provided that the site was dry. Tests
by Monsanto and others of PCBs in the environment had
shown that the higher chlorinated PCB congeners were
being retained in organisms and that there was an absence
of PCBs with three chlorines or less. Some initial successes
had been obtained using biodegradation of PCBs under lab
conditions. The apparent lack of lower chlorinated species
in the environment led Monsanto to develop Aroclor 1016
as a more environmentally acceptable product. By this time,
Monsanto had made it known that it would supply Aroclors
only to the electrical industry since the electrical applica-
tions were considered to be enclosed. Information was pre-
sented which suggested that the health effects of PCBs were
minimal. Interestingly, the health effects observed in the
Yusho incident were thought to have been caused by PCDFs
as impurities which were typically found ‘in some European
PCBs’. The correlation between PCBs and PCDFs had been
shown by Vos et al. (1970) who found that the relative con-
centrations of the PCDF isomers present in Yusho oil and in
two samples of used heat exchanger PCBs (Kanechlor 400
and Mitsubishi-Monsanto T1248) were strikingly similar.
The mechanism for the interconversion of PCBs into PCDFs
was not published until 1979 [Buser and Rappe, 1979].
By 1971 Monsanto had determined that about 75% of
the PCBs in the environment could be attributed to plasticiz-
ers, lubricants, hydraulic fluids, incineration of PCB mate-
rials and open dumps with the remainder coming from the
electrical industry. It was concluded that there was sufficient
biological evidence to indicate that PCBs can be deleterious
to the health of animal and human life and that, even though
it could not be expressed quantitatively, it was inappropriate
for electrical equipment manufacturers to ignore the weight
of the evidence against PCBs.
Electrical equipment manufacturers were to inform
customers about the nature of PCBs, and the hazards asso-
ciated with them. Instructions were to be provided on the
proper disposal of units containing PCBs. PCB manage-
ment controls were to be initiated in manufacturing facili-
ties. Customers were to be informed that the disposal ofPCB liquid waste should be done by sending the material to
Monsanto for incineration while failed or non-serviceable
units should be sent back to the manufacturer so that the
PCB in the unit could be disposed of adequately. All of the
maintenance and repair shops were to be alerted concern-
ing the nature of PCBs and, again, a procedure set up for
the proper use and disposal of the liquid and solid waste.
Equipment manufacturers intended to encourage NEMA
and other industrial organizations to establish uniform use,
handling and disposal standards. Field records of PCB
equipment performance were to be obtained.
June 1971: The National Industrial Pollution Control
Council published “The Use and Disposal of electrical
Insulating Liquids” in June 1971 and included in their report
recommendations to minimize the possibility of entry into
the environment of PCBs used in capacitors and transform-
ers. These regulations were later developed by a committee
of ANSI.
In July 1971, leakage of a heat exchanger fluid caused
contamination of pasteurized fish meal which in turn was fed
as a ration to chickens and catfish.
In July 1971: discovery of PCBs in food wrappings due
to recycling of copy paper in the production of paper pulp.
Occurrence of PCBs in turkey and chicken fed PCB-
containing products (reason unknown).
FDA began recall of 50 tons of meat, 300 tons of fish
feed, and 3,300 tons of fish meal contaminated with PCBs
caused by a leak in a heat exchanger system.
In August 1971, Westinghouse’s Power Transformer
Division issued an updated set of ‘Instructions for Handling
Inerteen® Insulating Fluid P.D.S. 54201 CM and Installation
and Maintenance of Inerteen Transformers.’ [Westinghouse,
1971], which incorporated the earlier supplemental notice of
environmental concerns and waste disposal. In this version
of the guide disposal suggestions are much more explicit
and contain recommendations for Inerteen liquid, solvent-
rinses contaminated with Inerteen and solids, including
drums, contaminated with Inerteen. Environmental concerns
were also expressed to the equipment purchaser much more
explicitly in this document than in the earlier 1968 version:
“ ... a carefully planned program of waste disposal must be
followed at every step of the equipment life. This includes
manufacture, repair and final disposition of the fluid and the
Inerteen contaminated parts. ”
On August 3, 1971, FDA called an Interagency meeting
of spokesmen from several Federal agencies and research
laboratories to review PCBs. OST released its report on PCB
environmental impact in March 1972.
September 1971, Monsanto introduced Aroclor 1016 as
a replacement for Aroclor 1242 in capacitors. The fluid was
made by vacuum distillation of Aroclor 1242 to remove the
more highly chlorinated PCB homologs since these were
recognized as being less biodegradable than the lower chlo-
rinated congeners.
September 1, 1971 representatives of several Agencies
of the Federal Government established an Interdepartmental
Task Force to coordinate the scientific efforts relative to
understanding PCBs. The Agencies involved were USDA,C016_003_r03.indd 853C016_003_r03.indd 853 11/18/2005 1:12:24 PM11/18/2005 1:12:24 PM