Track B Review : PCN
Polychlorinated Naphtalenes (PCNs)
Track B review for the
UNECE LRTAP Task Force
on Persistent Organic Pollutants
May 2006
Reviewers:
Erik Gravenfors
Swedish Chemicals Inspectorate (KEMI), Sweden
Sergey Kakareka
National Academy of Sciences, Belarus
André Peetersweem
Information Centre for the Environment, Netherlands
Track B Review : PCN
SUMMARY
Until the 1970s PCNs were high volume chemicals. The most important uses, in terms of volume,
have been in cable insulation, wood preservation, engine oil additives, electroplating masking
compounds, feedstocks for dye productions, dye carriers, capacitors and in refracting index oils.
Besides these uses PCNs are also present in technical PCB formulations and can also be formed in
thermal processes, of which waste incineration is the most important.
The dossier gives a good overview of the way the production and use of PCNs has evolved over the
last century and has stopped. There are however indications on unknown or illegal production and
use that need to be elaborated further.
The information on PCN emissions is satisfactory for Europe but data on the PCN emissions from
North America need to be explored.
The latest findings from air and snow samples that indicates ongoing sources of technical PCNs
need to be further examined.
The information regarded socio-economic factors is extremely limited. However, the need to
explore this information any further is probably not urgent due to the fact that there is no demand
for PCNs anymore.
Introduction
Polychlorinated Naphtalenes (PCNs) was nominated by The European Commission in September
2005 for inclusion into the POP Protocol. To support the nomination a report prepared by the
Netherlands in 2002 was sent in at the same time. Later on in December 2005 an addendum to the
original report was sent in and in January 2006 another document was sent in with responses to
recieved comments on the reports of the PCNs.
In conclusion the dossier for PCN now consist of the following three documents:
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Van de Plassche EJ, AMGR Schwegler. 2002. Polychlorinated Naphthalenes. Dossier
prepared for the third meeting of the UN-ECE Ad hoc Expert Group on POPs. Royal
Haskoning report L0002.A0/R0010/EVDP/TL;
Belfroid A., E. van der Aa and F. Balk. 2005. Addendum to the risk profile of
Polychlorinated Naphthalenes. Royal Haskoning report 9R5744.01/R0006/ABE/CKV/Nijm;
Belfroid A, Blok H, van der Aa E and Balk F. 2006. Response to the comments on the
dossier of the POP-candidate PCNs. Royal Haskoning.
This review is part of the Track B reviews for the TFPOP in 2006 and will focus only on the parts
of the dossier concerning extent of the release to the environment and socio economic factors.
Track B Review : PCN
Release to the Environment
The references in the dossier concerning production, use and emissions are generally complete.
Production and Use
Until the 1970s PCNs were high volume chemicals. The global production was estimated to be
approximately 150,000 metric tonnes between 1920 and 1980. The most important uses, in terms of
volume, have been in:
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cable insulation
wood preservation
engine oil additives
electroplating masking compounds
feedstocks for dye productions
dye carriers
capacitors
refracting index oils
Besides these uses PCNs are also present in technical PCB formulations and can also be formed in
thermal processes, of which waste incineration is the most important (see emissions).
The dossier gives a good overview of the way the production and use of PCNs has evolved over the
last century and has stopped. Because the production has stopped there is a lack of data on some
aspects but for the same reason there is no need for additional data. However, this overall picture
may not be totally correct. There are indications that PCNs are produced up to now and additional
information in the addendum to the risk profile indicates possible ongoing illegal sale and use of
PCNs. Further investigations on the scale of these unknown but indicated production and uses of
PCNs will be needed in order to evaluate the overall impact from these possible emission sources.
Emissions
Since the main production and use of PCNs belongs to the past the remaining sources will be
historical use of PCNs, historical and present use of PCBs, thermal process such as Municipal
Waste Incineration and emissions from landfills. In the addendum to the risk profile an annual
emission of PCNs in UNECE-Europe for the year 2000 was calculated to be 1.03 tonnes per year
divided on the following emission source categories:
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Public power and heat:
Residential combustion
Industrial combustion and processes
Solvent and product use
Waste incineration
1%
10 %
11 %
6%
74 %
The same information for North America would be informative.
In the addendum to the risk profile there is a study on PCNs in air and snow which indicates
ongoing sources of technical PCN based on the congener fingerprint. The highest levels were
detected in urban/industrialized areas of Poland, London and Moscow. It is unclear if the calculated
emissions for the year 2000 includes these emissions.
The dossier gives ample information on the emission of PCNs that is linked to the use of PCBs. A
Track B Review : PCN
total world wide production is estimated of 169 ton as a by-product of the production of PCBs. It is
unclear for which year this estimation was made. If possible information about the year for which
the production estimates were made would be helpful.
Incineration of waste is an important source of remaining emissions of PCNs. Many results are
given of emission measurements at waste incinerators.
It is unclear whether these data concern the raw gases from the incinerators or the clean gases.
Are these data measured before emission abatement installations or after? And if these data are
measured in the clean gases, what types of abatement techniques are used? Are these data measured
at installations that are equipped with only a dust removal system, or are these data measured at
installations that are based on the use of the Best Available Techniques as described in the EU BAT
reference document for waste incineration? This need to be sorted out.
The emissions from possible remaining production and usage of PCNs are not estimated. The
environmental levels in air measured at 71 locations in 22 countries across the Euoropean continent
indicates that there are also emissions from technical mixtures of PCNs. There is a need for
additional data on this issue.
Socio-Economic Factors
The information in this section is extremely limited. The main reason for this lack of information is
that PCNs are not hardly in use anymore.
Alternatives/Substitutes
The only available information here is that since the production of PCNs has been stopped as early
as in the seventies and eighties, PCNs must have been substituted by other chemicals. These
chemicals have not been identified and further discribed in the dossier.
Emission Control Techniques
The use of PCBs and waste incineration are assumed to be the most important remaining sources of
emissions of PCNs. The emissions of PCNs from these sources are reduced by the same measures
that are already taken to reduce the emission of PCBs from the use of PCBs and to reduce emissions
of PCBs and dioxins from incineration.
Cost and Benefits of Control
No information is available on cost and benefits of control.