02/11/18NDL-PCBs_EQS_20110119.doc
Non Dioxin-Like PolyChlorinated Biphenyls
Polychlorinated Biphenyls (PCBs) belong to a category of chemical compounds formed by the addition of chlorine to biphenyl. There are 10 possible positions for chlorine substitution and therefore 209 congeners are theoretically possible.
With few exceptions, PCBs were manufactured as a complex mixture of congeners, through progressive chlorination of batches of biphenyl until a certain target percentage of chlorine by weight was achieved. Commercial mixtures with higher percentages of chlorine contained higher proportions of the more heavily chlorinated congeners, but all congeners could be expected to be present at some level in all mixtures.
While PCBs were manufactured and sold under many names, the most common were the "Aroclor" series, in many of which a numerical identifier included the percentage of chlorine (e.g. "Aroclor 1254", with 54% chlorine)
Ballschmitter et Zell (1980) introduced a system of sequential numbers for the 209 congeners. This congener numbering is almost universally adopted as a de facto standard.
Among the 209 congeners, there are 12 “Dioxin-Like” compounds (DL-PCBs) which are:
PCB 77:3,3’,4,4’-Tetrachlorobiphenyl(CAS#: 32598-13-3)
PCB 81:3,4,4’,5-Tetrachlorobiphenyl(CAS#: 70362-50-4)
PCB 105:2,3,3’,4,4’-Pentachlorobiphenyl(CAS#: 32598-14-4)
PCB 114:2,3,4,4’,5-Pentachlorobiphenyl(CAS#: 74472-37-0)
PCB 118:2,3’,4,4’,5-Pentachlorobiphenyl(CAS#: 31508-00-6)
PCB 123:2,3’,4,4’,5’-Pentachlorobiphenyl(CAS#: 65510-44-3)
PCB 126:3,3’,4,4’,5-Pentachlorobiphenyl(CAS#: 57465-28-8)
PCB 156:2,3,3’,4,4’,5-Hexachlorobiphenyl(CAS#: 38380-08-4)
PCB 157:2,3,3’,4,4’,5’-Hexachlorobiphenyl(CAS#: 69782-90-7)
PCB 167:2,3’,4,4’,5,5’-Hexachlorobiphenyl(CAS#: 52663-72-6)
PCB 169:3,3’,4,4’,5,5’-Hexachlorobiphenyl(CAS#: 32774-16-6)
PCB 189:2,3,3’,4,4’,5,5’-Heptachlorobiphenyl(CAS#: 39635-31-9)
The 197 other congeners are the so-called “Non-Dioxin-Like Polychlorinated Biphenyls” (NDL-PCBs).
The following 7 congeners (including one DL-PCB) are the most often analysed in monitoring programmes and referred to as “indicator PCBs”or the "7 standard PCBs": PCB 28, PCB 52, PCB 101, PCB 118 (DL), PCB 138, PCB 153 and PCB 180.
As the main aim of this factsheet is to synthesise ecotoxicological and toxicological information in view of the determination of an Environmental Quality Standard and to address measured and calculated environmental concentrations, it seems relevant to address all the so-called “indicator PCBs” but the DL-PCB 118, which are most often monitored, that is to say PCB 28, PCB 52, PCB 101, PCB 138, PCB 153 and PCB 180.
1Chemical identity
Common name / Polychlorinated biphenylsChemical name (IUPAC)
Synonym(s) / PCBs, CBs
Chemical class (when available/relevant) / Chlorinated organic compounds
CAS number / PCB 28:2,4,4'-triCB7012-37-5
PCB 52:2,2';5,5'-tetraCB35639-99-3
PCB 101:2,2',4,5,5'-pentaCB37680-73-2
PCB 138:2,2',3,4,4',5'-hexaCB35065-28-2
PCB 153:2,2',4,4',5,5'-HexaCB35065-27-1
PCB 180:2,2',3,4,4',5,5'-heptaCB35065-29-3
Total PCBs7 indicator PCBs*1336-36-3
EC number (EINECS) / Total PCBs:215-648-1
Molecular formula / The chemical formula can be presented as C12H10-nCln, where n, the number of chlorine atoms in the molecule, can range from 1 to 10.
Molecular structure /
Molecular weight (g.mol-1) / MonoCB (3 cong.):188.45
DiCB (12 cong.):222.9
TriCB(24 cong.):257.35
TetraCB (42 cong.):291.8
PentaCB (46 cong.):326.25 / HexaCB (42 cong.):360.7
HeptaCB (24 cong.):395.15
OctaCB (12 cong.):429.6
NonaCB (3 cong.):464.05
DecaCB (1 cong.):498.5
* including DL-PCB 118.
2Existing evaluations and Regulatory information
Annex III EQS Dir. (2008/105/EC) / IncludedExisting Substances Reg. (793/93/EC) / No
Pesticides(91/414/EEC) / Not notified
Biocides (98/8/EC) / Not notified
PBT substances (793/93/EC) / Yes
Substances of Very High Concern (1907/2006/EC) / No
POPs (Stockholm convention) / PCB are listed in Annex A and Annex C to the Stockholm Convention
Other relevant chemical regulation (veterinary products, medicament, ...) / No
Endocrine disrupter
Petersen et al., 2007 / -Cat. 1 – At least one in vivo study providing evidence for endocrine disruption in an intact organism, for Human health and Wildlife:PCB 28, PCB 52, PCB138 and PCB180
Groshart and Okkerman, 2000 / -Cat.1 – At least one study providing evidence of endocrine disruption in an intact organism. Not a formal weight of evidence approach: Total PCBs, PCB 153
- Cat. 3 A (w) – No scientific basis for inclusion in list. No data available on wildlife relevant endocrine effects: PCB 52
3Proposed Quality Standards (QS)
3.1Environmental Quality Standard (EQS)
Insufficient dataon effects of exposure to single NDL-PCBs were available as regards aquatic organisms (water and sediment) as well as concerning birds and mammals. Consequently, neither QS, nor EQS could be derived for NDL-PCBs.
Value / CommentsProposed AA-EQS for [biota] [µg.kg-1biota ww]
Corresponding AA-EQS in [freshwater] [µg.l-1]
Corresponding AA-EQS in [marine waters] [µg.l-1] / Insufficient data availableon effects of exposure to single NDL-PCBs / See section 7
Proposed MAC-EQS for [freshwater] [µg.l-1]
Proposed MAC-EQS for [marine waters] [µg.l-1] / Insufficient data availableon effects of exposure to single NDL-PCBs / See section 7.1
3.2Specific Quality Standard (QS)
Protection objective[1] / Unit / Value / CommentsPelagic community (freshwater) / [µg.l-1] / Insufficient data availableon effects of exposure to single NDL-PCBs / See section 7.1
Pelagic community (marine water) / [µg.l-1]
Benthic community (freshwater) / [µg.kg-1dw] / Insufficient data availableon effects of exposure to single NDL-PCBs / see section 7.1
Benthic community (marine) / [µg.kg-1dw]
Predators (secondary poisoning) / [µg.kg-1biota ww] / No available information on effects of exposure to single NDL-PCBs / See section 7.2
[µg.l-1]
Human health via consumption of fishery products / [µg.kg-1biota ww] / No available information on effects of exposure to single NDL-PCBs / See section 7.3
[µg.l-1]
Human health via consumption of water[2] / [µg.l-1] / No available standard or guideline
4Major uses and Environmental Emissions
4.1Uses and Quantities
Commercial use of PCBs began in 1929. Since then over 1 million tonnes of PCBs have been produced world-wide OSPAR, 2004.
Given their extraordinary chemical stability and heat resistance, PCBs were extensively employed as components in electrical and hydraulic equipment and lubricants.
They have been used in two types of applications:
-Closed uses: dielectric fluids in electrical equipment such as transformers, capacitors (big industrial capacitors, but also small capacitors in household electrical appliances), heat transfer and hydraulic systems.
-Open uses: as plasticiser for rubber and for synthetic resins, carbonless copy paper, adhesives, paints, sealants, concrete additives, printing inks, pesticide extenders, industrial oils, flame retardants and to control dust on roads.
In the 1970s, owing to severe concerns pertaining to their human toxicity, suspected carcinogenicity, and environmental persistence, several countries limited the use of PCBs. Finally in 1985, the use and marketing of PCBs in the European Community were very heavily restricted.
4.2Estimated Environmental Emissions
Results from e-PRTR, 2007 ():
Information from OSPAR, 2004
Use area / Estimated emissions / Master referenceWastes
Uncontrolled applications / <16t (for Germany period 1994/95) / cited in OSPAR, 2004
Historic pollution
Closed used: leakage, accidental releases / <11t (for Germany period 1994/95) / cited in OSPAR, 2004
By-products of thermal processes / <2t (for Germany period 1994/95) / cited in OSPAR, 2004
Estimated PCB emissions for Europe (including Eastern Europe) are 113 tonnes for year 1995. A clear downward trend in emissions can be observed since 1970s OSPAR, 2004.
Transformers, capacitors, hydraulic fluids are assumed to be closed systems. Closed systems imply that – in principle – PCBs cannot be released to the environment during use (e.g. PCBs as dielectric fluid in transformers). However, significant releases also from such closed applications were noticed (leakage, accidental releases e.g. explosions or overheating of transformers and capacitors).
It can be estimated that about a half of the total emissions from products in use are represented by emissions from small, uncontrolled applications. The PCB quantities used in open applications are difficult to retrieve and estimate. All open applications can be considered uncontrolled. Until the use in open applications was banned in the early 1970s, and assuming a service life of 15-25 years for the relevant products, it can be assumed that most of these open applications would already have been forwarded to waste treatment by now. On the other hand, it can be assumed that certain applications, for example in construction materials, were designed for longer periods of use (40 years for some paints and sealing materials). The use of PCBs in the production of carbonless copy paper is responsible for the fact that elevated PCB levels were still measured in recycled paper for a long time after discontinuation of the production in 1972. The use of such recycled paper in toilet paper presumably led to a significant emission of PCBs to the hydrosphere.
Nowadays, most emissions originate from wastes and waste disposal: volatilisation from landfills containing transformer, capacitor, and other PCB-wastes, sewage sludge, spills, dredge spoils, improper or illegal disposal to open areas. Dir. 96/59/EC[3] contains stipulations regarding the elimination of PCBs. According to this directive, disposal or decontamination of equipment containing PCBs should be completed by 2010. The only exception is for transformers containing 50 to 500 ppm of PCB, which are allowed to remain in service until their end of life. However, there is no requirement to carry out an inventory under Dir 96/59/EC for products containing less than 0.005 % (by weight) of PCB. Besides, not all amounts of PCBs produced and used have been disposed of properly. This is particularly the case with regard to small capacitors used in private households, because they are widely distributed. Furthermore, PCB containing capacitors can still occasionally be found in new appliances since some third countries may still be producing PCB.
In a long-term perspective, the redistribution of PCBs previously introduced into the environment (historic pollution) is expected to be the major source of PCB exposure. This redistribution involves volatilisation from soil and water into the atmosphere with subsequent transport in air and removal from the atmosphere via wet/dry deposition of PCBs bound to particulates.
Emissions can also be expected from various thermal processes as a by-product.
5Environmental Behaviour
PCBs were produced as mixtures of different congeners of chlorinated biphenyl. The relative importance of the environmental fate mechanisms generally depend on the degree of chlorination of the congeners. Once released into the environment and subjected to weathering, or taken in by plants or animals and partially stored/metabolised/excreted, substantial changes in the congener ratios occurred, and continue to occur.
5.1Environmental distribution
Master referenceWater solubility (mg.l-1) / 1 10-6 – 7 at 25°C
The solubility in water is extremely low and decreases with increasing level of chlorination / MacKay et al., 2000
Volatilisation / PCBs are considered as semi-volatile.
Vapour pressure (Pa) / 1.2 10-5 – 3.69 at 25°C / MacKay et al., 2000
Henry's Law constant (Pa.m3.mol-1) / 1.72 – 151.4 / MacKay et al., 2000
Adsorption / The range 15070 – 440400 is used for derivation of QS. thus,
Organic carbon – water partition coefficient (KOC) / The higher the chlorination, the stronger the adsorption will be[4]. / IPCS, 1992
15070 – 440400 / US-EPA, 2008
Suspended matter – water partition coefficient(Ksusp-water) / 377.65 – 11010.9 / Calculated from KOC
Bioaccumulation / The BCF value 70000 on fish is used for derivation of QS. Thus, BMF1 = BMF2 = 10.
Octanol-water partition coefficient (Log Kow) / 3.9 – 8.26
The KOW coefficient increases with chlorine content. / MacKay et al., 2000
BCF (measured) / 200 – 70000 (or more)
PCBs are biomagnified in the food chain and found in relatively high concentrations in top predators such as otters, seals and fish-eating birds.
The higher chlorinated congeners are accumulated more readily. / IPCS, 1992
5.2Abiotic and Biotic degradations
Master referenceHydrolysis / Hydrolysis does not significantly degrade PCBs / IPCS, 1992
Photolysis / Photolysis appears to the only viable abiotic degradation process in water. / IPCS, 1992
Biodegradation / The degradation of PCBs in the environment depends largely on the degree of chlorination of the biphenyl, with persistence increasing as the degree of chlorination increases.
Also, chlorine positions on the biphenyl ring appear to be important in determining the biodegradation rate. PCBs containing chlorine atoms in the para positions are preferentially biodegraded.
Microorganisms degrade mono-, di-, and trichlorinated biphenyls relatively rapidly and tetrachlorobiphenyls slowly, whilst higher chlorinated biphenyls are resistant to biodegradation.
Higher chlorinated congeners are biotransformed anaerobically, by a reductive dechlorination, to lower chlorinated PCBs, which may then be biodegradable by aerobic processes. / IPCS, 1992
From Sinkkonen and Paasivirta, 2000 (Baltic environment, annual average temperature about 7°C), the following half-life times can be suggested:
-trichlorobiphenyls: 60 days in water, 3 years in sediment
-tetrachlorobiphenyls: 3.5 years in water, 10 years in sediment
-pentachlorobiphenyls:7 years in water, 7-10 years in sediment
-hexachlorobiphenyls:13.5 years in water, 19 years in sediment
-heptachlorobiphenyls:27.5 years in water, 38 years in sediment
6Aquatic environmental concentrations
6.1Estimated concentrations
Compartment / Predicted environmental concentration (PEC) / Master referenceFreshwater / No data available
Sediment
Biota
6.2Measured concentrations
Compartment / Measured environmental concentration (MEC) / Master referenceWater / 6.45 10-2µg.L -1 (PEC1: quantified data only) / EU Monitoring Database, 2009
1 10-2µg.L-1 (PEC2: all data) / EU Monitoring Database, 2009
WWTP effluent / No data available
Sediment (< 2mm) / 191 µg.kg-1 dw (PEC1: quantified data only) / EU Monitoring Database, 2009
97.8 µg.kg-1 dw (PEC2: all data) / EU Monitoring Database, 2009
Biota (marine) / 0.13 – 0.79 µg sPCB/glipid weight (Herring muscle)
0.74 – 1.8 µg sPCB/glipid weight (Cod liver)
0.08 – 0.31 µg sPCB/glipid weight (Perch muscle)
0.40 – 1.3 µg sPCB/glipid weight (Dab muscle)
1.2 – 2.6 µg sPCB/glipid weight (Flounder muscle)
0.17 – 0.32 µg sPCB/glipid weight (Blue mussel) / Bignert et al., 2009
0.013 – 0.27 µg PCB-153/glipid weight (Herring muscle)
0.16 – 0.53 µg PCB-153/glipid weight (Cod liver)
0.039 – 0.135 µg PCB-153/glipid weight (Perch muscle)
0.040 – 0.068 µg PCB-153/glipid weight (Blue mussel)
Biota (marine predators) / 12 – 15 µg sPCB/glipid weight (Guillemot egg) / Bignert et al., 2009
0.10 – 0.38 µg PCB-153/glipid weight (Eelpout muscle)
2.0 – 2.7 µg PCB-153/glipid weight (Guillemot egg)
N.B.: it is acknowledged that a lot more data are available for concentrations of NDL-PCBs in biota (EFSA, 2010), sediment and water. However, it was chosen to report only one recent study in the table above for biota.
7effects and Quality Standards
According to EFSA, no health based guidance value for humans can be established for NDL-PCB because simultaneous exposure to NDL-PCB and dioxin-like compounds hampers the interpretation of the results of the toxicological and epidemiological studies, and the databaseon effects of individual NDL-PCB congeners is rather limited (EFSA, 2005). This remark should be considered valid for aquatic biota and birds, but also for water and sediment matrices where simultaneous exposure to NDL-PCBs and DL-PCBs occurs as well.
7.1Acute and chronic aquatic ecotoxicity
ACUTE EFFECTS / Master referenceAlgae & aquatic plants
(mg.l-1) / Freshwater / Selenastrum capricornutum / 48h
EbC50: 4.610-3 (DL-PCB 105) / Mayer et al., 1998
Marine / No available information
Invertebrates
(mg.l-1) / Freshwater / Palaemonetes kadiakensis / 168h
EC50: 310-3 (Aroclor 1254) / Mayer and Ellersieck, 1986
Marine / No available information
Sediment / No available information
Fish
(mg.l-1) / Freshwater / Oncorhynchus mykiss
EC50 26d: 3.210-4 (Aroclor 1254) / Birge et al., 1978
LC50 96h: 210-3 (Aroclor) / Agences de l'Eau, 1999
Marine / No available information
Sediment / No available information
CHRONIC EFFECTS / Master reference
Algae & aquatic plants
(mg.l-1) / Freshwater / Scenedesmus quadricauda / d
EC20: 110-4(Aroclor 1254) / Luard, 1973
Marine / No available information
Invertebrates
(mg.l-1) / Freshwater / Daphnia magna / 21d
NOEC> 110-3(NDL-PCBs 52, 118, 138, 153 or180) / Dillon et al., 1990
Marine / No available information
Sediment / No available information
Fish
(mg.l-1) / Freshwater / Oncorhynchus mykiss / 26d
LC1: 910-6 (Aroclor 1254) / Birge et al., 1978
Marine / No available information
Sediment / No available information
Some data are available for aquatic organisms exposed to DL-PCBs and PCBs mixtures but only one study reports a NOEC subsequently to exposure to NDL-PCBs only (Dillon et al., 1990). Therefore, there is insufficient information on effects of exposure to NDL-PCBs to derive QSwater for NDL-PCBs.
Tentative QSwater eco / Relevant study for derivation of QS / AF / Tentative QSMACfreshwater, eco / Insufficient information on effects of exposure to single NDL-PCBs / - / Insufficient data for derivation
MACmarine water, eco / -
AA-QSfreshwater, eco / Insufficientinformation on effects of exposure to single NDL-PCBs / -
AA-QSmarine water, eco / -
AA-QSfreshwater, sed. / - / -
AA-QSmarine water, sed. / - / -
7.2Secondary poisoning
Secondary poisoning of top predators / Master referenceMammalian oral toxicity / Rhesus monkey, female / Oral / 55 months / Immunological effets (decreased IgG and IgM)
Exposure to Aroclor 1254
LOAEL: 5 10-3 mg.kg-1bw.d-1
NOAEL: 1.710-3 mg.kg-1bw.d-1(LOAEL/NOAEL=3)
NOEC: 0.033 mg.kg-1biota ww (CF= 20) / Tryphonas et al., 1989
Cited in WHO, 2003
Avian oral toxicity / European starling / Exposure: general (industrial waste).
Exposure to Aroclor 1254
>50 – 120,000 mg/kgwet weight.
Effects: Overall decrease in nesting productivity, increased mortality in second brood nestlings, and abnormalities in adult behavior (decreased foraging trips). / Arenal et al., 2004
American kestrels (Falco sparverius) / Oral (females only), approximately 5 to 7 mgtotal PCBs.g-1bird.d-1
Exposure to Aroclors 1248, 1254 and 1260 for approximately 100 d prior to eggs hatching.
PCB concentrations in eggs of all generations have been found in eggs (0.03 to 0.34 mg/g).
Effects: Slower, delayed growth (both sexes) and fledging (females), lower thyroxine concentrations (males). / Fernie et al., 2003
Zebra finch (Taeniopygia guttata) / Oral (gavage, female finches before egg laying)
Exposure to 40 g of Aroclor 1248.
Effects in progeniture (50 d old): significantly smaller song control nuclei robustus arcopallialis. / Hoogesteijn et al., 2008
Some data are available for birds and mammals exposed to PCBs mixtures butno study reports effects of exposure to NDL-PCBs only. Therefore, there is insufficient information on effects of exposure to NDL-PCBs to derive QSbiota,sec.pois. for NDL-PCBs.
Tentative QSbiota secpois / Relevant study for derivation of QS / AF / Tentative QSBiota / Insufficient data for derivation
7.3human health
Human health via consumption of fishery products / Master referenceMammalian oral toxicity / Rat Sprague-Dawley / Oral / 2 years / Liver tumors
Linear extrapol., Slope factor : 2 (mg.kg-1.d-1)-1
Virtually sure dose for a 10-6 risk:
510-7mg.kg-1biota ww / Brunner et al., 1996; Norback and Weltman, 1985
Cited in US-EPA, 1997
CMR / PCBs are classified as Probably carcinogenic to humans (IARC: Group 2A; US-EPA: Group B2).
Dioxin-like PCBs are potentially responsible for carcinogenic effects of PCB mixtures.
Some data are available for rats exposed to PCBs mixtures but no study reports effects of exposure to NDL-PCBs only. Therefore, there is insufficient information on effects of exposure to NDL-PCBs to derive QSbiota,hh. for NDL-PCBs.
Tentative QSbiota hh / Relevant data for derivation of QS / AF / ThresholdLevel / Tentative QSbiota, hh
Human health / - / - / - / Insufficient data for derivation
Human health via consumption of drinking water / Master reference
Existing drinking water standard(s) / No available standard / Directive 98/83/EC (E.C., 1998)
No available guideline / WHO Guidelines for Drinking-water Quality (WHO, 2008)
Existing water quality criteria (WQC) and Water Quality Objectives (WQO) / -IKSR/ICPR (Rhine): 100 pg/L (individual congeners; WQO for fish consumption)
-USA: 170 pg/L (sum of PCBs; Water Quality Criteria for human health: carcinogenic risk due to drinking water + fish consumption)
-USA: 74 pg/L (sum of PCBs; WQC for wildlife) / ETOX, 2007
8Bibliography, Sources and supportive information