HET COLLEGE VOOR DE TOELATING VAN GEWASBESCHERMINGSMIDDELEN EN
BIOCIDEN
BIJLAGE II bij het besluit d.d. 8 februari 2013 tot toelating van het middel Kathon 910 SB
Biocide, toelatingnummer 13967 N
RISKMANAGEMENT
Contents
1.
2.
3.
4.
5.
6.
7.
8.
9.
Page
Introduction .................................................................................................................... 2
Identity ........................................................................................................................... 2
Physical and chemical properties ................................................................................... 3
Efficacy .......................................................................................................................... 4
Human toxicology........................................................................................................... 5
Environment ................................................................................................................... 9
Conclusion ................................................................................................................... 21
Classification and labelling ........................................................................................... 21
References................................................................................................................... 22
pag. 1 van 27
1.
Introduction
Kathon 910 SB biocide
This assessment concerns a biocidal product based on the active substance 4,5-dichloro2-octylisothiazol-3(2H)-one (DCOIT).
The assessment includes the following products:
Product
Applicant
PT
Kathon 910 SB biocide
7, 9 en 10 20121122 TB
Rohm and Haas
Europe Trading ApS
Application number
The active substance DCOIT has been notified for product types 7, 8, 9, 10 en 11. DCOIT
is placed on annex 1 of Directive 98/8/EC for PT8, which is not the product type for these
applications. The other active substances have not been placed on annex 1 of Directive
98/8/EC yet.
2.
Identity
2.1
Identity of the active substance
2.1.1
DCOIT
General
Active substance (ISO Common Name)
Name in Dutch
DCOIT (non-ISO)
DCOIT
Identity
Chemical name (IUPAC)
Chemical name (CA)
CAS No
EC No
Other substance No.
4,5-Dichloro-2-octylisothiazol-3(2H)-one
4,5-Dichloro-2-octyl-3(2H)isothiazolone
64359-81-5
264-843-8
-
Molecular formula
Molecular mass
Structural formula
C11H17Cl2NOS
282.2
The active substance is not yet included in annex I of Directive 98/8/EC.
A CAR of the active substance is available for PT8 (draft final, January 2010) and PT21
(first draft December 2010). RMS is Norway.
pag. 2 van 27
2.2
Physical and chemical properties of the active substance
2.2.1
DCOIT
Physical and chemical properties relevant to the risk assessment
Appearance
Off-white solid at 20°C
Surface tension
70.8 mN/m
Vapour pressure (Pa)
9.8x10-4 Pa at 25 °C
3
-1
Henry’s law constant (Pa m mol )
2.20x10-1 Pa.m3.mol-1 at 20 °C and pH7
Solubility in water (g/L or mg/L)
pH__5____:2.85 mg/l at 10°C
4.26 mg/l at 20°C
6.68 mg/l at 30°C
pH__7____:2.26 mg/l at 10°C
3.47 mg/l at 20°C
5.67 mg/l at 30°C
pH__9____: Technically not possible
(hydrolysis)
Partition coefficient (log POW)
2.8 (independent of pH) at 23 °C
Dissociation constant
No dissociation within an environmentally
relevant pH range.
UV/VIS absorption (max.) (if absorption > Neutral pH: λmax at 284 nm (ε 10314), 230
nm (ε 5924);
290 nm state  at wavelength)
Acid pH: λmax at 284 nm(ε 10618), 230 nm (ε
6100);
Basic pH λmax at 227 nm (ε 13527)
Hazard identification for classification and labelling
Flammability
Flashpoint: N/A
Flammability: Not highly flammable
Auto-flammability: 264 °C
Oxidising properties
Not oxidising
Explosive properties
Not explosive
2.3
Analytical methods for the technical active substance
Adequate analytical methodology is available to determine the content of active
substance and significant and/or relevant impurities in the technical active substance.
2.4
Overall conclusions active substance
The identity, physical and chemical properties and analytical methods of the active
substance are sufficiently described.
3.
Physical and chemical properties
3.1
Identity of the biocidal poduct Kathon 910 SB Biocide
Name
Kathon 910 SB Biocide
Content active substance
9.3% pure 4,5-dichloro-2-octyl-3(2H)-isothiazolone
(DCOIT)
Formulation type
AL
Packaging
Fluorinated HDPE (HDPE/F): 20kg, 175kg, 900kg,
1000kg
pag. 3 van 27
3.2
Physical and chemical properties of the biocidal product Kathon 910 SB
Biocide
Appearance
Very light yellow-green liquid
Explosive properties
Not explosive
Oxidising properties
Not oxidising
Auto-flammability
235 °C
Flashpoint or Flammability
Flashpoint: 142 °C
pH 1% solution
10% in acetone/water: 4.3
Relative density
D420 = 0.885
Storage stability/ Shelf life
2 years in fluorinated HDPE
Physical and chemical compatibility Not applicable
Viscosity
23 mm2/s at 20 °C
Surface tension
67.3 mN/m at 20 °C
3.3
Analytical methods for detection and identification
3.3.1
Analytical methods for analysis of the biocidal product Kathon 910 SB
Biocide
Preparation (principle of method)
HPLC-UV
3.3.2
Residue analytical methods
Adequate residue analytical methodology is available to monitor residues of the biocide taking into account all
possible exposure scenarios and the toxicity of the active substance(s).
3.4
Conclusions biocidal product Kathon 910 SB Biocide
The identity, the physical and chemical properties and the analytical methods of the biocidal product are
sufficiently described.
4.
Efficacy
Function
Kathon 910 SB Biocide is an preservative for films (PT07), fibre, paper (PT09), and
masonry which is added to polymeric (silicone) caulks, sealants, mastics, joining
materials, and silicone building materials (PT10) in order to control bactericidal, fungal,
and algal detoration in and on final products.
The product is based on 4,5-dichloro-2-octyl-2H-isothiazol-3-one, hereafter referred to as
DCOIT, and intended for professional use only.
Mode of action
DCOIT utilizes a two-step mechanism involving rapid growth inhibition leading to a loss of
viability. Growth inhibition is the result of rapid disruption of the central metabolic
pathways of the cell by inhibition of dehydrogenase enzymes. Key physiological activities
that are rapidly inhibited in microbial cells are growth (reproduction) and respiration
(oxygen consumption). These processes are critical in bacteria, algae, fungi, and
invertebrates, which explains why DCOIT is such a broad spectrum biocide.
Inhibition of cellular activity is rapid (within minutes), whereas, cell death (cidal activity) is
observed after several hours contact. Cell death from DCOIT results from the progressive
loss of protein thiols in the cell from one of multiple pathways. In general, the higher the
concentration of DCOIT, the shorter the contact time required for inhibition and kill. Other
isothiazolone biocides have been shown to generate free radicals within cells as
metabolism is disrupted. The production of these radicals is considered a critical factor
contributing to cell death and DCOIT is suspected to exhibit this same response in
microbial cells. The two step mechanism of action of DCOIT results in its broad spectrum
of activity, low use levels for microbial control, and difficulty in attaining resistance.
pag. 4 van 27
Resistance
No resistance to DCOIT is known. Considering that the authorisation is done under article
121 of the WGB this is acceptable.
Conclusions
Considering that the evaluation is done under article 121 of the WGB and that the product
has already been on the market for some time, it can be concluded that when used in
accordance with the proposed label (WG/GA), may be expected that:
 Kathon 910 SB Biocide is effective as a preservative in controlling bacteria, algae,
and fungi in polymeric (silicone) caulks, sealants, mastics, joining materials, and
silicone building materials.
5.
Human toxicology
DCOIT (4,5-Dichloro-2-octyl-2H-isothiazol-3-one) is an existing active substance, not
included in Annex I of 98/8/EC. An application for inclusion is submitted for DCOIT for
which Norway is the Rapporteur Member State. A draft final concept CA-report for
DCOIT (Sept 2010) is available.
5.1
Human health effects assessment active substance
Oral absorption of 4,5-dichloro-2-octyl-2H-isothiazol-3-one was estimated to be ca. 20%,
as 20% of the applied does was recovered in urine (no information on biliary excretion).
DCOIT is extensively metabolised. In several studies on dermal absorption rates between
17 and 70% were found related to the nature of the formulation and the concentration of
DCOIT in the formulation that was tested. For risk assessment the dermal absorption is
set at 24-51% for concentrations of approximately 0.25% and 22-31% for concentrations
of 2% and above.
Acute oral tests in rats and mice gave the following LD50 values: 1636 mg/kg bw (rat); 567
mg/kg bw (mouse). The LD50 values from dermal tests performed with formulations were
> 652 mg ai/kg bw (rabbit); >500 mg ai/kg bw (rat). The inhalation LC50 was 0.26 mg /L.
DCOIT is skin and eye corrosive and is a skin sensitizer in a maximization test at 0.01%.
In repeated dose oral studies with rats (oral 28-day) and dogs (dietary 90 day) the lowest
NOAEL (10 mg/kg bw/day) was found in the dog study based on minimal changes in
body weight, feed consumption, haematology and clinical chemistry parameters. Rabbits
were dermally exposed to a formulation containing DCOIT for 21 days with local effects at
0.35 mg/kg bw/day (LOAEL) and no systemic effects at the highest dose tested (1.75
mg/kg bw/day). Respiratory tract irritation and no systemic toxicity was seen at 0.63
mg/m3 in a 90-day study in rats (nose-only, 6h/d, 5/d/wk). The NOAEC from the study
was 0.02 mg/m3, but as the effects in the study were largely attributed to o-xylene present
in the formulation, a surrogate NOAEC of 0.25 mg/m3 was calculated from the LOAEC.
DCOIT was considered not genotoxic in in vitro and in vivo assays.
No effects on reproductive performance, hormone disruption or foetal development were
reported in rats. The parental NOAEL is 16 mg/kg bw for effects on reproduction and 10
mg/kg bw/day for developmental effects.
No data are available for carcinogenicity, but DCOIT is considered as not carcinogenic.
Studies of DCOIT Technical in ethanol demonstrated that 250-350 ppm a.i. is at or near
the threshold concentration for irritation and sensitization in humans.
Based on the above mentioned the following AELs were derived:
AELacute
AELlong term
0.04 mg/kg bw/day based on 28-day oral study (safety factor 100)
0.02 mg/kg bw/day based on 90-day dietary study in dogs (safety
factor 100)
Local effects
Studies of DCOIT Technical in ethanol demonstrated that 250-350 ppm a.i. is at or near
the threshold concentration for irritation and sensitization in humans.
pag. 5 van 27
The primary human health hazards associated with DCOIT are irritation of the skin, eyes,
intestinal tract or lungs, as well as, allergy following repeated skin contact. There is no
evidence of significant systemic toxicity at doses below those that gives significant local
irritation.
Therefore, acceptable exposure concentrations were determined:
AECdermal
AECinhalation
0.7 μg/cm2 (0.003%) based on repeated exposure human patch tests
0.005 mg/m3 based on the 13-week nose-only study (safety factor 48)
Data requirements active substance
No additional data requirements are identified.
5.2
Human exposure assessment active substance
5.2.1 General aspects
Kathon 910 SB Biocide
Kathon 910 SB Biocide is a liquid and contains 4,5-dichloro-2-octyl-2H-isothiazol-3-one
as active substance (9.5%). The proposed fields of use are:
PT 7: use as dry film preservative for polymeric (silicone) caulks, sealants, mastics, and
joining materials
PT 9 : use as preservative for polymeric (silicone) caulks, sealants, mastics, and joining
materials
PT10: use as masonry preservative for polymeric (silicone) caulks, sealants, mastics, and
joining materials
The formulation is intended for professional use only.
5.2.2 Identification of main paths of professional exposure towards active
substance from its use in biocidal product
An assessment of uses and exposure scenarios was made for the products. A summary
of uses is given in Table T.1 below.
Table T.1
Summary of uses
Concentration a.s.
in producta
Kathon 910
SB Biocide
9.5% a
Use
concentration
PT
Application
method
Frequency
100-1000 ppm
(0.01-0.1%)
71
Dosed to the end
use fluid using
automated
dosing/metering
system or
manually
Single
application
per batch
100-1000 ppm
(0.01-0.1%)
91
Dosed to the end
use fluid using
automated
dosing/metering
system or
manually
Single
application
per batch
100-1000 ppm
(0.01-0.1%)
101
Dosed to the end
use fluid using
automated
dosing/metering
system or
manually
Single
application
per batch
pag. 6 van 27
Potential
secondary
exposure
End-users
(professional
and nonprofessional),
adults by
touching,
children by
touching/ingesti
on
End-users
(professional
and nonprofessional),
adults by
touching,
children by
touching/ingesti
on
End-users
(professional
and nonprofessional),
adults by
touching,
children by
touching/ingesti
on
a
Worst-case concentrations were used. Slightly lower concentrations were finally concluded in the PGB, however,
differences were marginal and did not affect the outcome of the risk assessment. For Kathon 910 SB 9.5% was
used instead of 9.3%.
1
Professional use
Non-professional use
2
As the product is used by professionals, oral exposure is considered negligible.
Respiratory and dermal exposure will be possible during (de)connection of the packages
to the dosing device and when manually pouring the product into the system. In addition,
during cleaning of the system professionals could be exposed. Considering the low
vapour pressure of the active substance (9.8 x 10-4 Pa at 25 °C), considerable inhalation
exposure is not to be expected.
5.2.3 Identification of main paths of non-professional exposure towards active
substance from its use in biocidal product
The products are intended for professional use only.
5.2.4 Indirect exposure as a result of use of the active substance in biocidal
product
During application of Kathon 910 SB Biocide in PT 7, 9 and 10 products, dermal and
inhalation exposure of professional and non-professional users to DCOIT is possible. In
addition, dermal exposure of the general public by touching of treated products/surfaces
cannot be excluded. For children concomitant oral exposure via hand-mouth contact may
be possible.
5.3
Human health effects assessment product
5.3.1 Toxicity of the formulated product
Kathon 910 SB Biocide
Studies with Kathon 910 SB Biocide have been submitted for acute oral and dermal
toxicity as well as for skin and eye irritation. For the remaining endpoints the classification
and labelling of the formulation has been prepared based on the calculation method
described in Annex I of Regulation 1272/2008/EC (CLP).
The formulation Kathon 910 SB Biocide does not need to be classified on the basis of its
acute oral (LD50 rat >5000 mg/kg bw) and dermal toxicity (LD50 rat >5000 mg/kg bw).
The formulation Kathon 910 SB Biocide needs to be classified as H332, ‘Harmful if
inhaled’.
The formulation Kathon 910 SB Biocide is considered irritating to skin and needs to be
classified as H315, ‘Causes skin irritation’.
The formulation Kathon 910 SB Biocide is considered not irritating to eyes.
The formulation Kathon 910 SB Biocide needs to be classified as H317, ’May cause an
allergic skin reaction’.
5.3.2 Data requirements formulated product
No additional data requirements are identified.
5.4
Risk characterisation for human health
Starting point for the risk assessment is the dermal AEC of 0.7 µg/cm2 (0.003%) for
DCOIT.
Inhalation exposure is expected to be low in view of the low vapour pressure of DCOIT.
5.4.1 Professional users
For dermal exposure during pouring of the formulation manually, a calculation of
exposure was made based on mixing and loading model 1 ((TNsG part 2 p 135). It is
assumed that Kathon 910 SB Biocide is manually added only when in plastic pails of 20
pag. 7 van 27
kg each. As no details on the number of batches produced per day has been provided by
the applicant, it is assumed workers will be exposed 4 times per day for maximum 0.5
hours per day. This would lead to a maximum dermal exposure of 150 mg/day for the
formulation, i.e. 14.3 mg DCOIT/day. It is assumed that exposure of hands and
underarms is possible (total surface 1980 cm2). This would lead to an exposure of 7
µg/cm2. Application of protective clothing (gloves and coverall) would lead to a reduction
of the exposure to the level of the AEC dermal of 0.7 µg/cm2.
Table T.2 Professional operator exposure to DCOIT and risk assessment for the use of
Kathon 910 SB Biocide
Estimated external
exposure (mg
/day)
Local AEC
Risk-indexa
Manual pouring, no PPE
Mixing/loading b Dermal
14.3 (7 µg/cm2)
0.7 µg/cm2
10
Manual pouring, with PPE
Mixing/loading b Dermal
1.43 (0.7 µg/cm2)
0.7 µg/cm2
1
Route
a
b
The risk-index is calculated by dividing the internal exposure by the AEC.
Exposure is estimated with mixing and loading model 1. Inhalation exposure was not taken into account, but in
view of the low vapour pressure of the substances in the formulation, this is considered negligible.
On the basis of the above considerations, it can be concluded that the risk when manually
loading the formulation Kathon 910 SB Biocide for the professional user is acceptable
with personal protection, i.e. gloves and coverall. A risk index of 1 is considered sufficient
here as especially the estimation of exposure with mixing and loading model 1 represents
a very worst case estimate, all other models e.g. mixing and loading model 3 (TNsG part
2 p 137) would lead to a 10-fold lower exposure estimation.
As the calculation presented above is expected to represent a worst case situation, the
risk related to all other uses during (de)connection, pouring and cleaning is considered to
be acceptable with personal protection, i.e. gloves and coverall.
5.4.2 Non-professional users, including the general public
The product is intended for professional use only.
5.4.3 Indirect exposure as a result of use
Secondary exposure of both professionals and non-professionals to products containing
Kathon 910 SB Biocide cannot be excluded during application. The concentration in the
products (0.01-0.1%) is above the AECdermal of 0.003% (0.7 μg/cm2).
A leaching study submitted by the applicant showed that the leaching rate from sealant
samples was less than 30 ng/cm2. The nominal levels of DCOIT in the sealants was 500
– 600 ppm. Products contain at maximum 1000 ppm DCOIT, therefore the leaching rate
was estimated to be 60 ng/m2 (factor 2). It is proposed that 18% of the potential surface
residue is transferred to the skin (data from TNsG, Part 2, p. 204 for dried fluid on various
types of surface). This would lead to an exposure of 10.8 ng/cm2. As this is below the
AECdermal of 0.003% (0.7 μg/cm2) it can be concluded that no adverse health effects are
expected from indirect exposure to DCOIT after dermal contact with products containing
DCOIT after application of Kathon 910 SB Biocide.
Several sensibilisation studies with formulated products have been submitted. Some
products are negative in a Buehler test, even up to concentration DCOIT of 1000 ppm
(0.1%). However, other products induced sensitizing reactions, in general in products with
concentrations from 500 ppm and above.
The active substance is a known sensitizer, for which in the CAR the setting of lower
specific concentration limit of 0.001% is suggested. DCOIT should be categorised as an
extreme sensitizer based on a maximisation assay with a specific concentration of
pag. 8 van 27
0.001%. Based on the above considerations all products containing Kathon 910 SB
Biocide needs to be labelled with DPD11 / EUH208 ‘Contains 4,5-dichloro-2-octyl-2Hisothiazol-3-one. May produce an allergic reaction’ or in case of a positive sensitization
test with R43 ‘May cause sensitisation by skin contact’ / H317 ‘May cause an allergic skin
reaction’.
5.4.4 Combined exposure
The product contains only one active substance and it is not described that it should be
used in combination with other formulations.
5.5
Overall conclusions
Kathon 910 SB Biocide
For the unprotected professional operator, adverse health effects after dermal/respiratory
exposure to DCOIT as a result of the application of Kathon 910 SB Biocide cannot be
excluded. Correct use of personal protective equipment (gloves and cover all) will reduce
the dermal exposure and results in a sufficient reduction of the exposure to DCOIT for the
application of Kathon 910 SB Biocide. Considering the low vapour pressure of the active
substance (9.8 x 10-4 Pa at 25°C), inhalation exposure is expected to be negligible.
Based on the risk assessment, it can be concluded that adverse health effects can be
excluded for the unprotected and protected professional and non-professional users after
indirect exposure to DCOIT as a result of use of Kathon 910 SB Biocide. Regarding the
sensitizing properties of DCOIT the products containing Kathon 910 SB Biocide must be
labelled accordingly (DPD11 / EUH208 ‘Contains 4,5-dichloro-2-octyl-2H-isothiazol-3one. May produce an allergic reaction’ or depending on concentration or test results, R43
‘May cause sensitisation by skin contact’ / H317 ‘May cause an allergic skin reaction’).
6.
Environment
6.1
Introduction
Kathon 910SB Biocide contain as active substance 4,5-dichloro-2-octyl-2H-isothiazol-3one (hereafter referred to as DCOIT). The intended uses are described in table E.1.
Kathon 910SB Biocide concern preservative for application in product types PT7, 9 and
10. The biocide is added to end product professionally, but treated products may be used
by non-professionals as well.
Table E.1.
Intended uses
No. Intended Use
1
6.2
Kathon 910SB Biocide:
Preservation of polymeric
(silicone) caulks, sealants,
mastics, and joining materials
(PT7, 9, 10)
Dosage
Indoor / Professional /
outdoor non
professionals
1.05 kg-10.53 kg for a both
one ton batch, which
is equivalent to
approximately 100
ppm to 1000 ppm
active ingredient.
Industrially
added
Treated product
is used by
Professionals
and Non
professionals
Environmental effect assessment
Risk assessment is based on predicted no-effect concentrations (PNECs) for the different
compartments which are derived from ecotoxicity data and applying assessment factors.
The assessment factor depends on the type of test performed (acute or chronic), the
pag. 9 van 27
toxicological endpoint (effect concentrations (ECs), no-observed effect concentrations
(NOECs), etc) and the number of data and is determined according to the Technical
Guidance document (version 2003 chapter 3). The PNECs based on the ecotoxicological
data for the active substances are presented in table E.2. The derivation of the PNECs is
described in Appendix I.
Table E.2.
PNECs for the active substance DCOIT
compartiment
PNEC
Lowest EC10/NOEC
AF
Test/species
Aquatic
0.034 μg/L*
0.34 μg/L
10
Navicula
pelliculosa
STP
0.064 mg/L
0.64 mg/L
10
Activated sludge
0.41 mg 14C
equiv./kg wwt
4.9 mg/kg dwt
10
Chironomus
riparius
Soil
0.062 mg/kg wwt
3.5 mg/kg dwt TWA
50
Earthworm
reproduction
Birds/mammals
1.55/4.49 mg/kg
food
5d LC50 >4640 mg
a.i./kg food /
NOECmammals 404
mg a.i./kg food
sediment
3000/ Bobwhite
40 quail/dogs
* Additionally for intermitted release (in case of complete release of a swimming pool) a PNEC
0.34 µg/L is derived, using the lowest NOEC with an assessment factor of 1.
6.3
Environmental exposure assessment
6.3.1
Chemistry and/or metabolism
In a ready biodegradation study, DCOIT was not classified as ready biodegradable. This
was most likely due to inhibition of the inoculums by DCOIT where at the test
concentration DCOIT was toxic to the microorganisms and thereby inhibiting
biodegradation. However, in a OECD 303A simulation test radioactive labelled carbon
that was found in the effluent could not be related to DCOIT, which was confirmed with
DCOIT analyses. It was therefore assumed that DCOIT quickly degrades in an STP.
Half-lives in the environment are short, being 0.689 day in water and 4.7 days in soil.
Metabolism involves cleavage of the isothiazolone ring and subsequent oxidation.
Dissipation of DCOIT in the environment comprises of biological degradation
(mineralization and primary degradation) with subsequent incorporation of the breakdown
products into the non-extractable residue fraction of soil and sediments. Abiotic
degradation via chemical reactions may also occur. The biodegradation of DCOIT in the
aquatic environment is given in Figure E.1.
pag. 10 van 27
Figure E.1 Aquatic metabolic pathway for DCOIT due to biodegradation
The main metabolites identified in the several abiotic and biotic degradation tests are
listed in Table E.3. The fraction of parent represents the highest fraction detected in the
respective environmental fate study.
pag. 11 van 27
Table E.3.
Metabolites of DCOIT
Metabolite
Max. % detected
N-(n-octyl) malonamic acid
16
(NNOMA)
In sediment
N-(n-octyl) acetamide (NNOA)
12.4
In sediment
N-(n-octyl) oxamic acid
31
(NNOOA)
In water phase
N-(n-octyl) oxamic acid
24.4
(NNOOA)
In water phase
(1-chloro-2-(n-octylcarbamoyl)(8.9)
1-ethene sulfonic acid)*
2-chloro-2-(n-octylcarbamoyl)-1- 11.8
ethene sulfonic acid
In water phase (at 100
ppb)
1-chloro-2-(n-octylcarbamoyl)-1- 11 (pH7, 40°C)
ethene sulfonic acid
In water phase
2-chloro-2-(n-octylcarbamoyl)-1- 11 (pH7, 40°C)
ethene sulfonic acid
In water phase
Reference endpoint
Seawater-sediment aerobic
biodegradation
Seawater-sediment aerobic
biodegradation
Photolysis
Estuarine water
biodegradation
Estuarine water
biodegradation
Estuarine water
biodegradation
Hydrolysis
Hydrolysis
* 1-chloro-2-(n-octylcarbamoyl)-1-ethene sulfonic acid was not formed in amounts > 10%;
however, concentrations of this metabolite were increasing during the course of the test, not
reaching a plateau at the end of the study. It is therefore possible that this metabolite might have
passed the 10% threshold if the study had been prolonged. Moreover, 1-chloro-… and 2-chloro-…
are isomers in equilibrium and it is not clear whether the ratio detected in the estuarine study
would always be that only 2-chloro-… is detected in amounts > 10%.
The cleavage of the isothiazolone ring results in metabolites which are less toxic than
DCOIT. The metabolites are an order of magnitude of 2 to 5 less toxic than DCOIT based
on acute toxicity data for aquatic organisms. Furthermore, the metabolites NNOMA and
NNOA are readily biodegradable and (Q)SAR predicts NNOOA to be readily
biodegradable. Therefore the risk assessment of DCOIT covers the risk assessment of its
metabolites. Risk assessments for the metabolites will therefore not be calculated and
presented in the product assessments.
6.3.2
Distribution in the environment
Various phases in the life cycle of a product may cause emissions and environmental
exposure. In the risk assessment, emissions from the polymer manufacturing, service life
and waste phase of the of the treated article are considered. Emissions from active
substance production are not included in the risk assessment. Table E.4 summarises the
receiving environmental compartments that have been identified as potentially exposed
during the use of the products for the different applications.
Table E.4.
Foreseeable routes of entry into the environment on the basis of the
intended use relevant for all three products.
Main scenario
Environmental compartments and groups of
organisms exposed
STP
Freshwat Saltwat Soil Air
Birds and
1
1
2, 3
er
er
mammals
preservation of polymers,
including sealants, mastics,
++
++
+/++
+/++ (Q) ++
+
joining materials, and
(Q)
roofing membranes
preservation of swimming
++
++
++
+
pool liners
(Q)
++ Compartment directly exposed, + Compartment indirectly exposed, (Q) Qualitative assessment,
depending on application, 1 Including sediment, 2 Including groundwater, and soil invertebrates
and arthropods, 3 In the Netherlands, surplus sludge of public STPs is not applied for fertilization
and soil improvement of agricultural soil. Therefore, exposure of soil and groundwater via STP
pag. 12 van 27
surplus sludge application is not part of the risk assessment. Due to the outdoor use of articles
treated with the products leaching from the treated articles to soil and water may occur.
6.3.3
Predicted environment concentration calculations
6.3.3.1 General
Predicted Environmental Calculation (PECs) were calculated according to relevant
exposure scenario documents (ESDs, release to the environment), the Technical
Guidance Document (distribution in the environment), and the model SimpleTreat
(concentrations for micro-organisms in an STP and the STPs’ effluent) by using the
default values for parameters, unless otherwise noted. Addition of the active substances
to end products is usually done indoors in a controlled environment regulated by various
legislations. Therefore, emission of the active substance during manufacturing of the end
products is considered negligible and will not be assessed. Release of DCOIT during the
waste phase is assessed either, because it is assumed that end-products to which
DCOIT is added are disposed as solid waste and usually burned.
6.3.4
Preservation of polymers
Emission scenario documents (ESDs) are available for PT07, PT09 and PT10. A
limitation of the PT07 scenario is that it calculates exposure from paints on regional scale
only based on the total tonnage of the product brought on the regional market. The
available scenarios for polymers in PT09 are based on total polymer production.
Therefore, predicted exposure concentrations (PEC) for PT07 and PT09 applications
were calculated using the ESDs for wood preservatives (PT08) and masonry
preservatives (PT10) as these provided realistic scenarios to assess exposure resulting
from outdoor application of polymers applied in fences, houses claddings, bridges, jetties,
and noise barriers on a local scale i.e. direct emission to soil and surface water from a
single application or the emission to one STP. The following exposure routes were
identified and assessed:
 direct release to surface water: PT08 offers a worst-case scenario for direct
exposure to surface water by leaching during service life. This scenario assumes
a bridge of 10 m² above a pond of 20 m³, which covers uses of treated polymers
above or adjacent of surface water. Degradation of DCOIT was taken into account
as water in ponds is stagnant and not refreshed;
 direct release to STP and indirect release to surface water: The scenario was
adapted from PT10 which offers a scenario for treating masonry in cities where
spills and precipitation holding the biocides (leachate) is collected and discharged
via the sewer system to a STP. For this specific use it was assumed that 125 m²
(TGD-default for façades and considered representative for flat roofs when
polymers are applied as roofing membranes) per house is covered with DCOITenriched polymers. This scenario results in PECs for STPs directly exposed and
PECs for surface water and sediment after purification of waste water. The
scenario, however, estimates the release from one treated building, while 4000
houses are connected to one STP (TGD default). However, emission by leaching
varies among these houses as some treated polymers are recently applied,
resulting in the highest leaching rates, while leaching from other locations is
remarkably lower or even negligible as the active substance is completely
leached. To correct for this, the service life of polymers was set to 10 years,
whereby it was assumed that all preservative in the polymers has leached within 3
year after application as data on long-term leaching was missing (see below). As
the service life is 10 years, the number of houses with polymers from which the
active substance is leaching was assumed to be 30%, from which a part (30/1095)
the active substance is leaching fast. The daily emission is therefore the sum of
fast and slow leaching. As not all roofs are covered with polymers but also other
material, it was assumed that 50% of the roofs were treated with polymers. This
results in 600 houses that contribute to the daily emission. Degradation was not
taken into account as the active substance is eventually released into a flowing
pag. 13 van 27

water body. As the significant lower surface of tarpaulins, the risk assessment for
roofing membranes covers this use as well;
direct release to soil: PECs for soil were calculated by applying the house
scenario according to PT08. This scenario assumes that the soil (12.5 m³)
adjacent of the façade (125 m²) is polluted by leaching from roofing membranes,
covering the application in tarpaulins as well. PECs were calculated without and
with degradation. Final PEC were calculated exclusive and inclusive degradation.
Uses in pool lining have been assessed separately using the PT02 public and private
swimming pool scenario. The swimming pool scenario takes into account three types of
release:
1.
direct emission to surface water from a one time release (complete pool volume
discharged to surface water)
2.
a daily discharge (chronic emission of a fraction of the swimming water)
3.
daily emission of a fraction of the swimming water to the STP.
It is assumed that the active is leached from the lining to the swimming water, which is
released to surface water or sewer. The PEC for direct release to surface water is
calculated using a dilution factor (see appendix III), concentrations in the STP and the
STP’s effluent are calculated using SimpleTreat using the parameters presented in
appendix II.
When in use DCOIT will leach from treated surfaces. The applicant has submitted a
leaching study showing a leaching rate of 10.9 mg/m²/d from polymers. However, this
study was done for polymers completely submerged in water that was shaken for 24
hours. This rate is appropriate to assess environmental exposure during the 30 days after
application, but because leaching may decrease in time, this value will overestimate the
PEC for the longer assessment period. Moreover, this leaching rate suggest that 100% is
leached in less than 150 days as the initial DCOIT concentration is 1620 mg/m² when an
average polymer thickness and density of 1 mm and 1.35 L/kg, respectively, is
considered. It was therefore assumed that the remaining DCOIT will leach completely in
three years, resulting in a leaching rate of 1.18 mg/m²/d. For swimming pools, however, a
different approach was used. Continuous release was modelled using a leaching rate of
10.9 mg/m²/d, which represents the worst-case i.e. emission from swimming pools with
recently applied liners. To assess emission from swimming pool liners in pools with an
annual water replacement, an average leaching rate of 1.48 mg/m²/d was used, based on
1620 mg DCOIT/m² and a service life of three years.
PEC were calculated by using the default values for parameters, unless otherwise noted
(Table E.4.) and the concentrations listed in Table E.1. (highest concentration only).
Emission during service life was calculated over 13 years (1095 days) representing the
worst-case. Input parameters including motivation, are listed in Table E.5. The input
parameters applied for SimpleTreat and the swimming pool scenario’s are listed in
Appendix II and III, respectively.
pag. 14 van 27
Table E.5. Input parameters
parameter
scenarios
Volume applied
Density of the product
Volume of soil adjacent to
surface treated
Cumulative quantity leached
over initial period (30 days)
Cumulative quantity leached
over longer period (1 year)
value
8.3.3.Wood preservatives:
brushing house
8.3.4.Wood preservatives:
brushing bridge
10.2. Masonry – In-situ
brushing of a façade of
a house in a city
n.a.
n.a.
12.5 m³
3.27E-04 kg/m²
remarks
Calculations made for both
application phase and
service-life
Polymers are manufactured
elsewhere in a controlled
environment. Emission to the
environment during
application is therefore not
expected.
As a result of the Technical
Meeting held in June 2011,
Milan, Italy, depth and width
of soils adjacent of buildings
is enlarged to 0.5 × 0.5 m,
and depth of soils distant to
buildings to 0.5 m.*
see explanation in section
6.3.4.
1.29E-03 kg/m²
Time for longer assessment
period
1095 days
Half lives in water (12°C)
Half lives in sediment (12°C)
Half lives in soil (12°C)
0.686 days
not available
4.7 days
pag. 15 van 27
Leaching was calculated
over a three year period,
considering as a realistic
worst-cas
Degradation rate constant in
an STP
see remarks
DCOIT was not detected in
an artificial STP when
biodegradability was
measured according to
OECD 303A. The measured
radioactive labelled carbon
was most likely related to
metabolites as
chromatographic analyses
did not detect DCOIT. The
metabolites are an order of
magnitude of 2-5 less toxic
as DCOIT, as discussed
previously. Therefore, it was
assumed that an STP
effectively removes 99% of
DCOIT from the influent.
PECSTP, however, was based
on a degradation rate
constant of 24/d (default).
Polymers applied indoors may have emission to an STP during cleaning. However,
Swedish data demonstrated that leaching from these products is about 0.05% per year.
On basis of the tonnage data provided and the emission factor it can be concluded that
emission to the local STP per day is insignificant. This route of exposure is therefore not
discussed further and covers intended uses such as vinyl floor and wall covering, water
beds, upholstery, boots and shoes. Mattress protection, may cause release to the sewer
when washed. This will occur only occasionally at present no scenario is available. It is
supposed that this type of use is covered by other uses with emission to the sewer.
6.3.5
Preservation of caulks
Kathon 910SB Biocide is only added to fillers and sealants, which are applied both
indoors and outdoors. Considering that the total volume of caulks is negligible compared
to polymers applied as swimming pool liners and roofing membranes, risk assessment of
the latter will cover environmental risks for caulks as well. No additional calculation
concerning caulks are therefore made.
6.4
Risk characterisation for the environment
For each relevant compartment, PECs are divided by PNECs. Risks are considered
potentially unacceptable when PEC/PNEC >1.
6.4.1
Water and sediment organisms and micro-organisms in the STP
Direct exposure to surface water
The risk characterisation for the aquatic compartment (freshwater and sediment)
receiving the active ingredients directly are presented in Table E.6.
Table E.6.
PEC and PEC/PNEC ratios for direct exposure to fresh water and
sediments.
fresh water
PEC (mg/L)
PEC/PNEC
sediment
Scenario
PEC (mg/kg
PEC/PNEC
wwt)
application in polymer above stagnant water (bridge scenario)
without degradation
4762
57
after 30 days
1.62E-01
2.34E+01
pag. 16 van 27
fresh water
PEC (mg/L)
PEC/PNEC
Scenario
23590
after 3 years
8.02E-01
with degradation
152
after 30 days
5.17E-03
17
after 3 years
5.78E-04
swimming pool (replacement of swimming water)
3.60
public
1.22E-02
58.7
private
2.00E-01
n.c.
sediment
PEC (mg/kg
PEC/PNEC
wwt)
283
1.16E+02
7.46E-01
8.36E-02
1.82
0.204
n.c.
n.c.
n.c.
n.c.
not calculated
Direct emission to surface water due to leaching from polymers applied in, above, and/or
adjacent of water or emptying swimming pool water directly into surface water will cause
an unacceptable risk for water organisms, even when degradation is taken into account.
Considering the negligible water-exposed surfaces of caulks compared to polymer
bridges and swimming pool liners, the application of DCOIT as preservative in sealants
and fillers will not result in unacceptable risks for the aquatic environment. Therefore, the
environmental standards are met, but only for applications in fillers.
Direct exposure to the STP and indirect exposure to surface water - outdoor use
The risk characterisation for the aquatic compartment (freshwater and sediment)
receiving the active ingredients indirectly via an STP are presented in Table E.7.
Table E.7.
Compound
PEC and PEC/PNEC ratios for micro-organisms in the STP and
freshwater and sediment indirectly exposed.
STP
PEC
PEC/PN
(mg/L)
EC
daily emission from 600
4.90E-03
houses in a city
swimming pool (continuous release)
public
2.02E-03
private
4.14E-04
fresh water
PEC
PEC/PN
(mg/L)
EC
0.077
5.37E-05
1.58
0.032
0.006
1.89E-04
3.86E-05
0.555
0.114
sediment
PEC
PEC/PN
(mg/kg
EC
wwt)
7.76E-03 0.019
n.c.
n.c.
n.c.
n.c.
The addition of DCOIT to polymers that are subsequently applied outdoors on façades
and roofing materials results in unacceptable risks for the aquatic environment. Note that
the results are ‘best case’ as it was considered that 100% of the precipitation is
discharged to an STP, while rainwater may also be directly discharged to surface
water.,The risks ratio is most likely to be an overestimation considering that rainwater
may be directly or indirectly discharged to soils as well, roofing materials are not applied
on all roofs as other roofing materials (panes) are used as well on a large scale, and the
roof surface is not proportional to the amount of houses connected to an STP (4000) as
apartment building roofs are shared by several houses. Moreover, the majority of roofing
membranes in The Netherlands consist in bitumen for which the application of DCOIT as
preservative is unlikely as bitumen are applied by heat and DCOIT is thermally unstable
(decomposition at 266°C
DCOIT applied in fillers and sealants has a significant smaller amount of surface that is
contacted with water. Therefore, the PECs resulting from leaching from these materials is
considered < 1 and will thus not result in unacceptable risks for the aquatic environment.
Also discharge of swimming pool water to an STP reduces the risks to acceptable levels
(Table E.7), but risks are expected when waste water is directly discharged to surface
water (Table E.6).
pag. 17 van 27
Because of unacceptable risks for the environment when discharged directly to surface
water, the application of DCOIT-treated polymers outdoors will be limited to applications
where direct discharge to surface water does not occur. Therefore, swimming pool water
containing DCOIT has to be released to the sewer connected to an STP. As discussed
previously, the use of polymers indoors is considered acceptable as emission to the
sewer is considered negligible.
Micro-organisms in an STP
For all intended uses, the standards for micro-organisms in an STP are met, as
PEC/PNEC ratios are all below 1.
6.4.1.1 Surface water intended for the abstract ion of drinking water
Present authorisations of DCOIT are for antifouling of seagoing vessels only, for which no
emission to abstraction points for the production of drinking water is expected.
There are no data available in the Pesticide Atlas regarding the presence of DCOIT in
surface water. A closely related active substance Isothiazolinon (OIT) (without the two
chlorine atoms) is on the recommended list of biocides to be monitored for drinking water
from surface water (RIVM, 2010). DCOIT is however not transformed to OIT and the
metabolites formed are different. From the general scientific knowledge collected by the
Ctgb about the products and the active substance, the Ctgb concludes that there are in
this case no concrete indications for concern about the consequences of this product for
surface water from which drinking water is produced, when used in compliance with the
directions for use. The standards for surface water destined for the production of drinking
water are met.
6.4.2
Atmosphere
Criteria for the examination of environmental risks to air are not specified in the form of a
numerical standard. The assessment of potential impacts on air quality, yet, is aimed to
minimize the risk for stratospheric ozone depletion. As there are no indications that
DCOIT contributes to depletion of the ozone layer (calculated half life is below the trigger
of < 2 days, DCOIT is not listed as ‘controlled substance’ listed in Annex I of Regulation
(EC) No 1005/2009 of the European Parliament), the environmental risk to air is
considered acceptable.
6.4.3
Terrestrial compartment
The risk characterisation for soils is presented in Table E.8.
Table E.8. PEC and PEC/PNEC ratios for soils
Compound
without degradation
after 30 days
after 3 years
with degradation
after 30 days
after 3 years
PEC (mg/kg wwt)
PEC/PNEC
1.92
9.53
31
154
0.338
4.68E-02
5.45
0.755
Although the PEC/PNEC ratio is <1 3 years after application due to degradation of
DCOIT, the concentration quickly increase and peaks after 30 days. Therefore, the
PEC/PNEC-ration will be >1 for a long time, which is considered unacceptable. However,
when DCOIT is applied in roofing membranes, the concentration in the leachate will
decrease quickly considering the fast degradation in water (0.68 days) and
photodegradation of DCOIT in water that is retained on roofs. Therefore, risks are likely
be lower than showed in Table E.8. and only temporarily as DCOIT degrades in soils as
well. Therefore, risks are considered acceptable and the standards for soils are met.
pag. 18 van 27
6.4.3.1 Soil or ganisms and non target arthropods (including bees)
The risk assessment to arthropods is considered to be similar to soil organisms due to
their direct contact with soils. The standards for soil arthropods are therefore met.
Because DCOIT is not systemic pesticides, secondary therefore exposure to bees
through pollen is considered negligible. Also direct exposure to bees is not expected,
hence, the risk for bees is considered acceptable for all intended uses.
6.4.3.2 Groundwater
Assessment of the drinking water criterion defines that the concentration of the active
substance and the relevant metabolites in groundwater for the preparation of drinking
water needs to be < 0.1µg/L. According to the OECD ESD PT8 (Appendix 4) substances
with a Koc of > 500 L/kg and a DT50 of < 21 days are not expected to leach to
groundwater. DCOIT has a mean Koc of 6610 L/kg and a DT50 of 4.7 days (12°C) and
thus fulfils those criteria. This was supported by a leaching study of DCOIT. Hence, the
emission to groundwater is considered neglible and will be < 0.1 µg/L and thus the
criteria for groundwater has been met.
6.4.3.3 Persistence in soil
Regarding persistency of DCOIT the half-live based on primary degradation in soil is 4.7
days and the main metabolites are readily biodegradable. Hence, the active substance
DCOIT is not persistent and the standards for persistence are met.
6.4.4
Non compartment specific effects relevant to the food chain
6.4.4.1 Bioconcentrat ion
Bioconcentration in fish
Based on the measured 14C residues, the steady-state BCF (whole fish) was 750 L/kg,
indicating a potential for bioaccumulationTherefore a secondary poisoning risk
assessment has been conducted, see 6.4.4.2
Bioconcentration in earthworms
No experimental BCF value for earthworm is available. A BCF was calculated according
to equation 82d of the TGD, using a default RHOearthworm of 1 kg (wwt)/L (as
recommended by the TGD) and the Kow of DCOIT of 631 L/kg. The resulting calculated
BCFearthworm is 8.4 L/kg, indicating a low bioaccumulation potential for terrestrial food
webs.
6.4.4.2 Primary and secondary poisoning of bir ds and mammals
The use in coatings and polymers is not expected to result in primary poisoning.
Exposure of birds/mammals eating contaminated fish is considered relevant, see the
argumentation above. The risk to birds/mammals through the aquatic food chain was 0.3,
based on the worst case PECfresh_water of the direct exposure to surface water and a
biomagnification water of 1. PNECoral can be found in Table E.2 . Therefore the criteria
for secondary poisoning of birds and mammals are met.
6. 5
Measures to protect the environment (risk mitigation measures)
Concept WG/GA and PUB have been checked.
6.6
Conclusion Environment
An authorisation of a biocide in the Netherlands is only possible when the risks related to
the product application are acceptable. An overview of the risks for products for which
authorisation is requested is given in Table E.9.
pag. 19 van 27
√
√
√
√
Overall
√
Birds and mammals
√
BCF
√
Persistence in soil
product and intended use
Kathon 910SB Biocide
preservatives for (silicone)
caulks, sealants, mastics, and 7/10 √
joining materials
Groundwater
Aquatic organisms
Sediment
organisms
Micro-organisms in
STP
Air
Drinking water from
surface water
Soil organisms
Non target
arthropods
Bees
Overall conclusions
Product type (PT)
Table E.9.
√
√
√
√
√
When used in accordance with the proposed label (WG/GA):
 Kathon 910SB Biocide comply with the environmental standards and will not cause
unacceptable effects on the environment.
pag. 20 van 27
7.
Conclusion
When used in accordance with the legal Instructions for Use (WG/GA), Kathon 910 SB
Biocide is sufficiently effective and no unacceptable risk is expected to human health, the
person who uses the product and the environment (Art. 121 jo art. 49 first paragraph
Dutch 2007 Plant Protection Products and Biocides Act).
Regarding the sensitizing properties of DCOIT the products containing Kathon 910 SB
Biocide must be labelled accordingly (DPD11 / EUH208 ‘Contains 4,5-dichloro-2-octyl2H-isothiazol-3-one. May produce an allergic reaction’ or, depending on concentration or
test results, R43 ‘May cause sensitisation by skin contact’ / H317 ‘May cause an allergic
skin reaction’).
8.
Classification and labelling
Proposed for classification and labelling for the formulation based on Reg. (EC)
1272/2008:
The identity of all substances in the mixture that contribute to the classification of the mixture *:
Pictogram:
GHS07
Signal word: Warning
GHS09
H-statements:
P-statements:
H332
Harmful if inhaled
H315
Causes skin irritation
H317
May cause an allergic skin reaction
H400
Very toxic to aquatic life
P273
Avoid release to the environment.
P280
P391
Wear protective gloves and protective clothing.
Collect spillage.
P501
Dispose contents/container to hazardous or special
waste collection point.
Child-resistant fastening obligatory?
Tactile warning of danger obligatory?
Not applicable
Not applicable
* according to Reg. (EC) 1272/2008, Title III, article 18, 3 (b)
1.
2.
Ctgb includes only the highly recommended P-statements on the label, therefore,
P261, P302+P352 and P333+P313 were not included in the label, as proposed by
the applicant.
Based on the ongoing discussions on bioaccumulation/biodegradation of DCOIT,
P501 is added to the label.
pag. 21 van 27
9.
References
Technical guidance document on risk assessment. Part II. European Commission Joint
Research Centre, EUR 20418 EN/2, 2003, Ispra, Italy.
Supplement to the methodology for risk evaluation of biocides ESD for PT10. Emission
scenario document for biocides used as masonry preservatives. Institute national de
l’environment industiel et des risques. INERIS report DRC-01-25582-ECOT-VMin°02DR0270, Verneuil-en-Halatte, France, November 2002. Available at
http://ihcp.jrc.ec.europa.eu/
Emission Scenario Document for Wood Preservatives. OECD Series on Emission
Scenario Documents. Organisation for Economic Co-operation and Development, Paris
Poel, P. van der, J. Bakker. Emission scenario document for biocides. Emission
scenarios for all 23 product types of the Biocidal Products Directive (EC Directive
98/8/EC). National Institute for Human Health and the Environment. RIVM report 601 450
009, Bilthoven, The Netherlands, 2002.
pag. 22 van 27
Appendix I. Profile of active substance DCOIT
PNEC derivation
Freshwater:
Acute and long-term studies are available for fish, invertebrates and algae both for
freshwater and marine species. According to the TGD data from freshwater and marine
species can be pooled for PNEC derivation if the difference in sensitivity between
freshwater and marine species within trophic levels is not larger than a factor of 10. This
is the case for DCOIT and the lowest NOEC used for PNEC derivation was the 24 hour
NOErC of 0.34 μg a.i./L from the test with the freshwater alga Navicula pelliculosa. An
assessment factor of 10 was applied to derive the freshwater PNEC:
PNECfreshwater = 0.034 μg a.i./L
Additionally for intermitted release (in case of complete release of a swimming pool) a
PNEC 0.34 µg/L is derived.
The PNECsediment can in principle be derived either from test results based on total
radioactivity or on parent substance. Biodegradation of DCOIT in sediment and
subsequent adsorption of the metabolites to organic matter in the sediment is fast. In the
wood preservative risk assessment (PT 8), biodegradation in sediment is not taken into
consideration and therefore the PNECsediment has been calculated from the lowest 14CNOEC available, which is 4.9 mg 14C equiv/kg dwt from the freshwater sediment test with
C. riparius. The PNECsediment therefore represents DCOIT and metabolites. The TGD
expresses PEC/PNEC ratios on a wet weight basis and the results have therefore to be
converted from dry weight to wet weight.
Not the standard conversion factor of 4.6 from EUSES was used for conversion but a
factor of 1.184. This conversion factor was calculated using measured data on sediment
characteristics in the study report for the C. riparius test. The NOEC based on total
radioactivity becomes 4.14 14C equiv/kg wwt sediment.
PNECfreshwater sediment (total radioactivity) = 0.41 mg 14C equiv./kg wwt sediment
STP:
An EC50 of 0.64 mg a.i./L could be established from a study on inhibition to microbial
activity with activated sludge. An assessment factor of 10 was used to derive the
PNECSTP:
PNECSTP = 0.064 mg a.i./L
Soil:
Acute studies are available for microorganisms, earthworms and plants. The
microorganism test can also be considered a long-term test and a chronic earthworm
study is available as well. The NOEC from the plant test is the same as the NOEC from
the 56 days reproduction test with earthworms (based on dry weight and nominal
concentrations); however, based on the TWA approach the NOEC from the long term test
with earthworms is the lowest endpoint and will be used for PNEC derivation with an
assessment factor of 50. The NOEC from this test based on nominal concentrations is
4.42 mg a.i./kg wwt soil. The TWA NOEC is 3.1 mg a.i./kg wwt soil. A factor of 1.13 was
used to calculate the endpoints from dry weight to wet weight. The AF cannot be lowered
from 50 to 10 as plants are the most sensitive species in the acute studies.
PNECsoil = 0.088 mg a.i./kg wwt soil (initial)
PNECsoil = 0.062 mg a.i./kg wwt soil (TWA)
pag. 23 van 27
PNECoral:
For birds short two term feeding studies are available; however, no LC50 could be
established. The 5d LC50 was above the highest concentration tested (4640 mg a.i./kg
food) in both tests with Mallard duck and Bobwhite quail. The PNECoral for birds is
derived from the LC50 with an AF of 3000.
PNECoral (birds) = 1.55 mg a.i./kg food
For mammals the lowest NOAEL was 10.1 mg a.i./kg bw/d from a 90-d subchronic toxicity
with dogs. To derive the NOEC the NOAEL is multiplied with a conversion factor of 40.
This gives a NOECmammals of 404 mg a.i./kg food. To derive the PNECoral for
mammals an AF of 90 was used.
PNECoral (mammals) = 4.49 mg a.i./kg food
pag. 24 van 27
Appendix II. Physical-chemical properties
parameter
value
molecular weight (g/mole)
vapour pressure at test
temperature (Pa)
test temperature vapour
pressure (°C)
solubility at test temperature
(mg/L)
test temperature solubility
(°C)
octanol-water partition
coefficient (L/kg)
organic carbon-water
partition coefficient (L/kg)
282.2
Henry constant (Pa  m3 
mol-1)
test temperature vapour
pressure (°C)
rate constant for
biodegradation in STP (/d)
remarks
0.00098
25
4.28
20
631
6610
-
No experimentally
determined Henry constant
available.
0
pag. 25 van 27
Not degradable in an STP
Appendix III. Scenario calculations
Table 1.
Discharge of swimming water by public swimming pools into the
sewage system for chronic situation
Variable/parameter (unit)
Symbol
S/D/O/ acute
chronic
P
Input:
AREAswim
Water surface
m²
D
440
440
w
DEPTHswi
Average depth of water
m
D
1.8
1.8
mw
Length
m
D
50
50
Width
m
D
17.6
17.6
Volume of the swimming pool
m³
Vpool
O
792
792
Treated area swimming pool
m²
Atreat
O
683.36
683.36
mg/m²/
10.9
Leaching rate
Qleach
S
1.48
d
Hydrolysis rate
/d
khydro
S
0.0098
0.0098
Number of visitors per day (-)
Nvisit
D
400
400
0.05
Water replaced per visitor (m3)
Vrepl
D
0.05
Output:
Leaching to pool per day
Eleach = Qleach * Atreat
mg/day
Eleach
O
1011
7449
Removal rate by replacement
kremoval =
/d
kremoval
O
0.0253
0.0253
Nvisit*(Vrepl/Vpool)
Retention time
R = 1/kremoval
d
R
S
39.6
39.6
Remained in pool per day after
leaching minus hydrolysis and
replacement
Qpool = Eleach * (1-khydromg/d
Qpool
O
976
7188
kremoval)
Remained in pool after leaching
minus hydrolysis and replacement
after XX days
Qpool_time = Qpool * R
mg
Qpool_time
O
38648
284637
Concentration in swimming water
Cproc = Qpool_time/Vpool
mg/m³
Cproc
O
48.8
359.4
Emission from the swimming pool
Elocalwater_acute =
Elocalwater
g/d
O
38.6
Cproc*Vpool
_acute
Elocalwater_chronic = (Nvisit
Elocatwater
g/d
O
7.2
* Vrepl * Cproc) / 1
_chronic
Table 2.
Discharge of swimming water by private swimming pools into the
sewage system for chronic situation
Variable/parameter (unit)
Symbol
S/D/O/ acute
chronic
P
Input:
AREAswim
Water surface
m²
D
72
72
w
DEPTHswi
Average depth of water
m
D
1.8
1.8
mw
Length
m
D
12
12
Width
m
D
6
6
Volume of the swimming pool
m³
Vpool
O
129.6
129.6
pag. 26 van 27
Treated area swimming pool
Leaching rate
m²
mg/m²/
d
/d
-
Atreat
O
136.8
Qleach
S
1.48
S
D
D
0.0098
10
0.05
0.0098
10
0.05
O
202
1491
O
0.0039
0.0039
S
259
259
O
200
1471
O
51764
381234
O
399
2942
O
51.8
Hydrolysis rate
khydro
Number of visitors per day (-)
Nvisit
Water replaced per visitor (m3)
Vrepl
Output:
Leaching to pool per day
Eleach = Qleach * Atreat
mg/day
Eleach
Removal rate by replacement
kremoval =
/d
kremoval
Nvisit*(Vrepl/Vpool)
Retention time
R = 1/kremoval
d
R
Remained in pool per day after
leaching minus hydrolysis and
replacement
Qpool = Eleach * (1-khydromg/d
Qpool
kremoval)
Remained in pool after leaching
minus hydrolysis and replacement
after XX days
Qpool_time = Qpool * R
mg
Qpool_time
Concentration in swimming water
Cproc = Qpool_time/Vpool
mg/m³
Cproc
Emission from the swimming pool
Elocalwater_acute =
Elocalwater
g/d
Cproc*Vpool
_acute
Elocalwater_chronic = (Nvisit
Elocatwater
g/d
* Vrepl * Cproc) / 1
_chronic
Table 3.
O
136.8
10.9
1.5
Discharge of swimming water by public and private swimming pools
into the surface water for the acute situation
Variable/parameter (unit)
S/D/O/
Symbol
public
private
P
Input:
DILUTIO
Dilution factor for (-):
D
4
2
N
DEPTHditc
Depth of ditch (m)
m
D
0.3
0.3
h°
Concentration in swimming water
kg.m3
Cproc
S
48.8E-6 399E-6
Parameters requiredfor distribution
modules
Fraction drift related to location and
Fdrift
Oc
1
1
way of application
c
Application interval
d
Tint
O
1
1
Number of applications in one year
Nappl
O'
1
1
Output:
Cwaterpest = Cproc / dilution
mg/L
0.012
0.200
1) Already defined in distribution model for pesticides (symbol DEPTHditch)
2) use symbols with subscripts (Fdrift, Tinterval and Nappl respectively)
pag. 27 van 27