PCBs AND ASSOCIATED AROMATICS 851
Aroclors”; Washington, D.C.: Bureau of Foods, Food and
Drug Administration, Public Health Service.]
During 1970, the Council on Environmental Quality (CEQ)
studied regulatory approaches to the problem of toxic chemicals
in the environment. In its report published in 1971, CEQ iden-
tified PCBs as a major problem. [Council on Environmental
Quality (1971): “Toxic Substances”; Washington, DC.]
Vos et al. (1970) published “Identification and Toxicolo-
gical Evaluation of Chlorinated Dibenzofuran and Chlorinated
Naphthalene in Two Commercial PCBs”.
Increased levels of porphyrins are consistent with chronic
hepatic porphyria that has been associated with exposures to
other polyhalogenated aromatics. This condition can range
from a subclinical state, where increased urinary porphy-
rin excretion results in no observed adverse effects, to por-
phyria cutanea tarda (PCT) which is a skin disease resulting
in excessive light sensitivity, scaling, and itching. Increased
levels of coproporphyrins and protoporphyrins in faeces and
porphyrins in liver, bile and the small intestines of chicks
fed Aroclor 1260, Clophen A60 and Phenoclor DP6 were
reported by Vos and Koeman (1970).
Morphological changes in monkeys were observed with
doses ranging from 1.4 mg/Kg/d to 16.4 mg/K/d and also
mice dosed with 12.8 mg/Kg/d [Nishizumi, 1970].
Aroclors 1221, 1232, 1242 and 1248 in high doses, bind
to estrogen receptors in the rabbit uterus [Bitman and Cecil,
1970].
Close parallels between the toxic effects of PCBs and
PCDFs/PCDDs were established in a series of studies and
reported in major scientific reviews such as [Crow, 1970].
Cleanup methods for analysis were devised to separate
DDT and its analogues from some of the PCBs [Amour and
Burke, 1970].
The Pesticide Regulation Division of the FDA issued
PR Notice 70–25 instructing manufacturers and formulators
of economic poisons containing PCBs and PCTs to change
their formulations to exclude these classes of compounds.
Open letter from GE Electric Utility Sales Division to
electric utility customers expresses environmental concerns
and starts “As you are well aware the public concern with
pollution is rapidly escalating.”
February 3, 1970: The FDA initiated a regulatory thresh-
old value of 5 ppm PCB in the edible flesh of fish, February
3, 1970.
August 1970: Fish near the effluent of Monsanto’s
Annison plant were found to contain PCB in August 1970.
August 1970: Cow’s milk was found to be contaminated
with PCBs (August 1970) from cows given feed that had
been stocked in silos coated with PCB-based products.
September 1970: The Office and Science and Technology
panel on Hazardous Trace Substances reviewed cadmium,
arsenic and PCBs. Also, the National Swedish Environment
Protection Board held a conference on PCBs. One of the
sessions of the conference highlighted “environmental prob-
lems”. This conference, perhaps for the first time, brought
together the extent of understanding of the manufacture, use,
extent of environmental contamination, analytical methods,
and biological effects of PCBs.September 14, 1970: An open letter from Monsanto,
dated September 14, 1970 states: “As a supplier of askarel
fluids namely Inerteen, Pyranol, and Aroclors which do con-
tain PCBs, we wish to inform you that the FDA announced
a guideline for PCB of 5 ppm in fish and 0.2 ppm in milk.
Therefore, control of waste and spills is imperative.”
A letter was sent to Monsanto customers requesting
information on the quantities of PCB fluids that might be
shipped to Monsanto for disposal so that the company could
design an appropriate sized incinerator.
October, 1970: At the October Double Client Committee
meetings, a subcommittee was formed to investigate PCB
disposal problems.
October 12–14, 1970: The International Electrotechnical
Commission Technical Committee No. 10; Liquid and
Gaseous Dielectrics Subcommittee 10B; Insulating Liquids
Other than Hydrocarbon Oils indicated in its minutes of
meeting dated October 12–14, 1970: “Agenda–Item 5—To
review current concern with the finding of PCBs in some
environments and what action should be taken in recom-
mending precautions in the application, processing and
effluent disposal of askarels to prevent them becoming envi-
ronmental contaminations... Copies of IEEE and ASTM
documents were circulated by the US Delegation. A French
Delegate circulated copies of a publication from Prodelac (a
French producer of askarels).”
October 28, 1970: Minutes of the IEEE Insulating
Fluids Subcommittee dated October 28, 1970 indicated
“Monsanto will, however, discontinue by the end of 1970,
the sale of Aroclors for application as plasticizers, heat
transfer agents, hydraulic fluids and other non-electrical
applications.”
November 19, 1970: A NEMA letter to (ANSI) dated
November 19, 1970, regarding the proposed committee on
the disposal of askarel used in electrical equipment indicates
“... The Monsanto Company has already taken steps to
limit the availability of askarel to those users where the fluid
is essential and is contained in a closed system, such as is
the case for transformers and capacitors. With the coopera-
tion of transformer and capacitor manufacturers, steps have
been taken to alert all known users on the problem and on
corrective measures. Monsanto has also instituted a means
for disposing of askarel-soaked waste materials, coils, insu-
lation, scrap, discarded capacitors, etc.”
November 1970: Occurrence of PCBs in chickens fol-
lowing absorption from PCB-containing plastic wrappings.
In December 1970, Monsanto sent a letter to end users
of PCB products requesting information on the amount and
types of solid PCB contaminated materials that might be
shipped to Monsanto for disposal. Monsanto was in the pro-
cess of sizing the design for a kiln to incinerate PCB wastes
and intended to make the service generally available.1971In 1971 Monsanto began to phase out production of the
more highly chlorinated Aroclors: 1232, 1248, 1260, 1262
and 1268.C016_003_r03.indd 851C016_003_r03.indd 851 11/18/2005 1:12:24 PM11/18/2005 1:12:24 PM