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Propoxur

1. CHEMICAL IDENTITY

Common Name: Propoxur

Chemical name (IUPAC): 2-isopropoxyphenyl methylcarbamate

Propoxur is a carbamate insecticide; biocide.

CAS Number 114-26-1

Log KOW

1.52 Water solubility 1860 mg/L

Chemical structure

Molecular Formula: C11H15NO3 Molecular Weight: 209.25 g·mol−1

Persistence Field half-live in soil: 14 to 50 days; Hydrolysis is both pH and temperature dependent. Under acidic conditions, propoxur is relatively stable. At neutral pH (7), half-life is 30 days at 30°C.

2. EXISTING EVALUATIONS AND REGULATORY INFORMATION

- Propoxur is not approved anymore as biocide in the EU (since 2010).

Off. J. European Comm. L96/37, 15.4.2009

http://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32009D0324&from=EN

http://ec.europa.eu/food/plant/pesticides/eu-pesticides-

database/public/?event=activesubstance.detail&language=DE&selectedID=1775

3. PROPOSED QUALITY STANDARDS (QS)

The PNEC we used for propoxur for the STE run was a value of 0.01 µg/L, reported as EQS in the Netherlands

(referring to NL Specific Pollutants).

Derivation of the NL AA-EQS value can be found in: http://www.rivm.nl/bibliotheek/rapporten/601501002.pdf

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The experts from Germany commented that the review of the PNEC is needed.

To our best knowledge, the only other Quality Target value presently available is the one proposed in Germany (equal to 0.3 µg/L): (https://webetox.uba.de/webETOX/public/search/ziel.do):

DE QS value is derived based on to the lowest LC50 of the short-term tests with Gammarus lacustris:

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As both EQSs are derived from the acute data, we decided to keep the lower NL EQS value.

4. MAJOR USES

Propoxur is used in veterinary medicine against flea infestation of dogs and cats. It is also used in pest control

for other domestic animals, mosquitoes, ants, gypsy moths, and other agricultural pests. It can also be used as

a molluscicide. Several U.S. states have petitioned the Environmental Protection Agency (EPA) to use propoxur

against bedbug infestations, but the EPA has been reluctant to approve indoor use because of its potential

toxicity to children after chronic exposure.

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https://en.wikipedia.org/wiki/Propoxur

5. ENVIRONMENTAL BEHAVIOUR AND EFFECTS

The hydrolytic half-life of propoxur is 16 days at pH 8, but the half-life could not be determined at pH7 as no

hydrolysis occurred during the 107-day observation period. The photolytic half-life in neutral aqueous solution

is approximately 10 days. Bacterial degradation of propoxur was the same under aerobic or anaerobic

conditions, with half-lives ranging from 80 to 210 days (depending upon soil type). Propoxur leached readily

from soils, moving with the water front. Based on these results, propoxur is unlikely to remain in the location

where it is applied. However, because it is readily decomposed, propoxur is unlikely to become a persistent

environmental contaminant.

(http://www.cdpr.ca.gov/docs/risk/rcd/propoxur.pdf)

Propoxur is very highly to highly toxic to many bird species, but its toxicity varies by the species. The

compound is not expected to accumulate significantly in aquatic organisms. The calculated accumulation

factor for propoxur is nine times the ambient water concentration.

(http://extoxnet.orst.edu/pips/propoxur.htm)

According to the harmonised classification and labelling approved by the European Union (under regulation

(EC) No 1272/2008 on classification labelling and packaging (CLP) of substances and mixtures), this substance

is toxic if swallowed (acute oral toxicity category 3, H301), is very toxic to aquatic life and is very toxic to

aquatic life with long lasting effects.

(http://echa.europa.eu/substance-information/-/substanceinfo/100.003.676)

The EU Pesticides database provides a classification with regard to toxicological data for propoxur:

(http://ec.europa.eu/food/plant/pesticides/eu-pesticides-

database/public/?event=activesubstance.detail&language=DE&selectedID=1775)

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CLP inventory from ECHA:

https://echa.europa.eu/information-on-chemicals/cl-inventory-database/-/discli/details/47788

6. MEASURED ENVIRONMENTAL CONCENTRATIONS (2006-2014)

Inland whole water - Sc2-PNECQC

Data statistics: Number of countries with measurements, number of sites with measurements, total number of

samples, number of samples with concentration below LOD, number of samples with concentration below

LOQ, and aggregate percentage of non-quantified records (< LOD/Q).

countries sites samples samples < LOD samples < LOQ % non-quantified

5 174 3646 3474 95.3

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Statistics for concentrations of all measurements: min, average (mean), standard deviation (SD), median,

percentiles (25, 75, 90, 95, 99) and max (µg/L).

min mean SD median P25 P75 P90 P95 P99 max

0.0025 0.0107 0.0101 0.01 0.01 0.01 0.01 0.01 0.05 0.46

Range of LODs / LOQs and number of records reported as quantified samples.

Note: For some quantified samples MS reported (or not) both LOD and LOQ. For this reason, a double

counting of the number of samples is possible.

LOD (µg/L) Missing 0.025 0.05

# samples 155 2 15

LOQ (µg/L) Missing 0.005 0.02 0.05

# samples 66 61 43 2

Range of LODs / LOQs and number of records reported as non-quantified samples. No records with LOD.

LOQ (µg/L) 0.005 0.02

# samples 156 3318

Note: The monitoring data for propoxur was checked in detail. Unfortunately, for the “quantified” records in

some cases no LOD/Q was reported, and some MS or laboratories reported exact the identical value as the

concentration quantified at different sites and for different samples. We suspect that in these cases the

substance was not detected/quantified in the sample but that half of the LOD/Q was reported as the

quantified concentration (according to Directive 2009/90/EC). This may lead to 'false positives' when these

reported values are above the PNEC. For propoxur, this check revealed that around 110 quantified records in 4

countries with concentrations higher than PNEC were available, so that the quality of the collected data is

satisfactory good.

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Boxplot of concentrations of all measurements per year (the table below indicates the number of samples per

year).

Year 2006 2007 2008 2009 2010 2011 2012 2013

# samples 999 922 218 264 156 179 576 332

Annual mean concentrations of all measurements per year (the time-trend is indicated by a dotted line).

Although the high number of samples per year available there is not a clear downward time-trend.

0

0.002

0.004

0.006

0.008

0.01

0.012

0.014

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014

Propoxur: annual mean concentrations (µg/L)

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Boxplot of concentrations of all measurements per country (the table below indicates the number of samples

per country).

Country #05 #07 #12 #13 #19

# samples 2 1506 1904 15 219

STE assessment results: Spatial, temporal and extent factors, STE score, risk rank, and PNEC value (µg/L).

CAS Fspat Ftemp Fext STE score Risk Substance PNEC

#114-26-1 0.172 0.170 0.110 0.452 5 Propoxur 0.01

STE assessment results: additional information for Fspat (site and country frequency of exceedances) and Fext

(extent of exceedance by Risk Quotient_P95) factors.

site_freq country_freq EXCextent

2.874E-01 6.000E-01 5.910E+00

Note: there is a considerable reduction of STE score (from 2.07 to 0.452) when the refined STE tool is applied

after the 6th SG-R meeting.

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Inland whole water - Sc2

Note: Scenario Sc2 is provided in the factsheet only for information and this scenario is not used in the final

judgment of substances. Because the database used for Sc2 is completely independent from the chosen

PNECs, it is faster to assess the impact of a PNEC change on the STE score for sc2 rather than for sc2 PNECQC.

This is why Sc2 was used to provide a first assessment of the impact of PNEC changes when such a request has

been received from the SG-R. If the substance is selected for a finalisation of the PNEC, the STE score for sc2

PNECQC will be recalculated once the PNEC is agreed upon.

Data statistics: Number of countries with measurements, number of sites with measurements, total number of

samples, number of samples with concentration below LOD, number of samples with concentration below

LOQ, and aggregate percentage of non-quantified records (< LOD/Q).

countries sites samples samples < LOD samples < LOQ % non-quantified

5 883 7246 112 6962 97.6

Statistics for concentrations of all measurements: min, average (mean), standard deviation (SD), median,

percentiles (25, 75, 90, 95, 99) and max (µg/L).

min mean SD median P25 P75 P90 P95 P99 max

0.0025 0.0162 0.0092 0.02 0.01 0.02 0.025 0.025 0.025 0.46

STE assessment results: Spatial, temporal and extent factors, STE score, risk rank, and PNEC value (µg/L).

CAS Fspat Ftemp Fext STE score Risk Substance PNEC

#114-26-1 0.860 0.957 0.070 1.887 2 Propoxur 0.01

STE assessment results: additional information for Fspat (site and country frequency of exceedances) and Fext

(extent of exceedance by Risk Quotient_P95) factors.

site_freq country_freq EXCextent

8.596E-01 1.000E+00 2.500E+00

Note: there is a small reduction of STE score (from 2.062 to 1.887) when the refined STE tool is applied after

the 6th SG-R meeting.

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7. ANALYTICAL METHODS

SPE of 300 mL water; LC-MS-MS; LOD: 0.0002 µg/L (Baugros et al., 2008).

8. CONCLUSIONS

Summary of the findings in the factsheet:

1) Propoxur, with a proposed PNEC of 0.01 µg/L, has been analysed in 5 countries, at 883 monitoring

stations (sites) with 7246 measurements (scenario 2), and 2.4 % of them quantified (> LOD/Q). In sc2-

PNECQC, 174 sites and 3646 samples are available in 5 countries, 4.7 % of them quantified.

2) A detailed check of the monitoring data for propoxur revealed that around 110 reliable quantified

records in 4 countries > PNEC were available.

3) LODs / LOQs below the PNEC (0.005 µg/L) have been reported, and a publication in the literature was

found.

4) The STE score of sc2-PNECQC is very low (0.452 with PNEC=0.01 µg/L), indicating a low risk to the

aquatic environment, but the scenario Sc2 showed a high STE score (2.062 with PNEC=0.01 µg/L).

5) According to the harmonised classification and labelling approved by the European Union, this

substance is very toxic to aquatic life, and is very toxic to aquatic life with long lasting effects.

6) Propoxur is not approved anymore as PPP in the EU nor is it approved for use in biocidal products.

Conclusion of the JRC:

According to JRC, based on the available evidence, propoxur could be a possible candidate for EQS

derivation. However, propoxur is not currently authorised for use in the EU nor is it approved for use in

biocidal products.

Conclusion of the SG-R:

SG-R concluded that Propoxur is not a good candidate substance for EQS derivation and consideration as PS.

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9. REFERENCES

Baugros, J.-B., Giroud, B., Dessalces, G., Grenier-Loustalot, M.F., Cren-Olivé, C.; Multiresidue analytical

methods for the ultra-trace quantification of 33 priority substances present in the list of REACH in real water

samples. Analytica Chimica Acta 607 (2008) 191-203.

Herrchen, M., Müller, M., Storm, A. 2000. Ableitung von Zielvorgaben für prioritäre Stoffe zum Schutz von

Oberflächengewässern.

COMMISSION DECISION of 14 April 2009 concerning the non-inclusion of certain substances in Annex I, IA or IB

to Directive 98/8/EC of the European Parliament and of the Council concerning the placing of biocidal

products on the market (2009/324/EC); Off. J. European Comm. L96/37, 15.4.2009.

http://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32009D0324&from=EN

Crommentuijn T, Kalf DF, Polder MD, Posthumus R, van de Plasche EJ. 1997. Maximum permissible

concentrations and negligible concentrations for pesticides. RIVM Report no. 601501002.

Comments from NL and UK

Text has been slightly revised according to general comments as follows:

1. Chemical Name (IUPAC) has been added

2. Link corrected:

Off. J. European Comm. L96/37, 15.4.2009

http://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32009D0324&from=EN

3. CLP Inventory from ECHA has been added

4. Conclusions:

Propoxur is not approved anymore as PPP in the EU nor is it approved for use in biocidal products.

5. References:

COMMISSION DECISION of 14 April 2009 concerning the non-inclusion of certain substances in Annex

I, IA or IB to Directive 98/8/EC of the European Parliament and of the Council concerning the placing of

biocidal products on the market (2009/324/EC); Off. J. European Comm. L96/37, 15.4.2009.

http://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32009D0324&from=EN

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Other comments are reported below:

Comments from NL

Text:

The experts from Germany commented that the review of the PNEC is needed.

Comment from NL, 23 August 2016:

The Dutch AA-QS is indeed a rather old value. On the other hand, I don’t agree on the German QS at all,

because an AF of 100 was applied to an EC50. This is not in accordance in with the TGD-EQS. Besides that,

from the RIVM report it appears that Gammarus is not the most sensitive species in acute toxicity tests in the

Dutch report, p. 199 (Daphnia magna, Chironomus tentans, Pteronarcys californica). Further, a quick look at

EPA’s ECOTOX database shows that there are many more data available. The lowest NOEC in US EPA ecotox

database is 4.54 ug/L from a 28-d test with Americamysis bahia the PNEC needs to be revised.

Text:

STE assessment results: Spatial, temporal and extent factors, STE score, risk rank, and PNEC value (µg/L).

CAS Fspat Ftemp Fext STE score Risk Substance PNEC

#114-26-1 0.994 0.966 0.110 2.070 2 Propoxur 0.01

Comment from NL, 6 August 2016:

PNEC is very uncertain. If the PNEC would change for example to the NOEC for Americamysis bahia with a

factor of 10, the PNEC would be 0.45 ug/L. In that case there would be no exceedance of the PNEC (max value

= PNEC) and thus the STE score would become virtually zero.

Text:

According to JRC, based on the available evidence, propoxur could be a possible candidate for EQS

derivation. However, propoxur is not currently authorised for use in the EU.

Comment from NL, 19 August 2016:

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We disagree, the PNEC is too uncertain for a prioritization, a change in PNEC to lowest NOEC /10 could

eliminate all exceedance. Further, the substance is not approved in EU.

Comment from Scottish Environment Protection Agency (SEPA), August 2016

More information on previous use quantities would be useful, since the substance is no longer authorised for

use but, although relatively mobile in the water environment, may be relatively persistent in some limited

situations like lakes where water refresh is low.

No data on Scottish use.

Comment from Environment Agency (EA, England), August 2016

JRC note that based on the available evidence propoxur could be a possible candidate for EQS derivation but

also note that it is not currently authorised for use in the UK.

Based on the data presented in the datasheet we don’t feel there is sufficient data to support its further

consideration:

- The datasheet indicates some discussion on the PNEC used. A Dutch value of 0.01ug/l was proposed

which was derived in 1997. The Germans have proposed a value of 0.3ug/l. Clarification of the PNEC and its

effect on the STE need to be considered further. A revised STE value would need to be calculated if revisions

were made to the PNEC.

- Monitoring data was available for 5MS however 95.3% were non-quantified. In addition JRC noted

that some of the quantified results may be false positives and actually be based on <values.

- It is not approved for use in the EU as a plant protection product and this along with the above

uncertainties suggest it is not a candidate for further consideration at this time.

Based on the above, we consider that propoxur is not considered a candidate for EQS development. Although

the monitoring data is too limited to make an assessment it is not currently considered to be a Watch List

candidate due to the information on its use which notes it is not currently approved for use in the EU as a

plant protection product and no other key uses were noted.

JRC reply: JRC could test in the STE runs additionally other PNEC values for this substance.