Guidance for Meeting the SIDS Requirements (The SIDS Guide)

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3.4 Guidance for Meeting the SIDS Requirements (The
SIDS Guide)
In order to assure harmonized responses from Member countries and to
ensure consistency on requests for further testing, this guidance
document (SIDS guide) has been developed. This documents show data
requirements and Test guidelines to be used on each data element.
Note: Figures in [ ] correspond to the data elements in the HEDSET and
in the Revised OECD HPV Form 1.
1. GENERAL INFORMATION
[1.01 A.] CAS-number
· Should always be stated.
[1.01 C.] Name of the Substance
· Should always be stated.
· Use the name supplied by the OECD.
[1.01 D.] CAS-descriptor
· Should be stated where applicable for complex chemicals.
[1.01 G.] Structural Formula
· Should be given where possible.
[1.5] Quantity
· Should be given where possible.
· Information on production and/or import levels should be
provided as tonnes per annum (or ranges, e.g., 100-500
tonnes, see Annex 6 to Section 2.5) per country and the
date for which those figures or ranges apply should be
given.
[1.7] Use Pattern
· Should be given where possible.
· Data on use pattern should be given by assigning main
types according to their exposure relevance, industrial

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categories and use categories. Detailed explanation on
categories is given in Annex to Section 2.6 and the
HEDSET explanatory note.
· If the chemical is present in consumer
products as marketed, details should be
mentioned on;
- function of the products (e.g. detergent etc.),
- weight fraction of the chemical in products
and
- physical state of products as marketed (e.g.
aerosol, powder or liquid))
[1.9] Sources of Exposure
· Should be given where possible.
· Describe sources of potential human or environmental
exposure including emission data if available for all phases
of the life cycle of the chemical including manufacturing and
user areas.
· For environmental exposure, indicate the production
process briefly, number of sites of manufacture and the basis
for concluding that the process is "closed" if applicable.
· Indication of measured exposure levels can be mentioned
here. Any information that will help to focus the assessment
of exposure can be mentioned, if available
2. PHYSICAL-CHEMICAL DATA
[2.1] Melting Point
· Should always be stated for substances other than gases
(and liquids whose melting point is lower than
approximately 0°C.) Temperature of decomposition is
acceptable.
· OECD Test Guideline 102
[2.2] Boiling Point
· Should always be stated for substances other than gases or
solids and liquids which either boil above 300°C or
decompose before boiling (in which cases estimates based
on vapour pressure or the boiling point under reduced
pressure are necessary). Temperature of decomposition is
acceptable.
· OECD Test Guideline 103
[2.3] Density (Relative Density)

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· Where applicable, indicate the relative density of the
substance. This property is generally more important for
inorganic chemicals.
· OECD Test Guideline 109
[2.4] Vapour Pressure
· Should always be stated.
· Calculations which indicate that the value is probably less than 10-5kPa
at 25°C, could preclude the need for testing.
· If a boiling point cannot be quoted due to decomposition or the melting
point is above 360°C, it may not be necessary to conduct this test. If a
melting point is <360°C but >200°C, a limit value based on measurement
or a recognised calculation method is acceptable.
· This test is not essential for chemicals with a boiling point of <30°C.
· OECD Test Guideline 104
[2.5] Partition Coefficient (n-Octanol/water)
· Should always be stated.
· Even for those substances which are extremely
soluble/insoluble in either phase, an attempt should be made
to provide a limit value (if necessary based on the individual
solubilities in n-Octanol and water). It is recognised that for
surface active substances, the measured result may only be
approximate.
· The MedChem database is a good source of data.
· If the test cannot be performed, a calculated value for Log
Pow should be provided. However it should be noted that
calculated values which are higher than 6 are, in general, not
reliable.
· For calculation of Pow, see e.g.:
- C. Hansch, A.J. Leo in Substituent Constants
for Correlation Analysis in Chemistry and
Biology, John Wiley, New York, 1979.
- W.J. Lyman, W.J. Reehl, D.H. Rosenblatt
(ed.), Handbook of Chemical Property
Estimation Methods, McGraw-Hill, New York,
1983.
- Annex to OECD Test Guideline 117.
- Application of Structure Activity
Relationships to the Estimation of Properties
Important in Exposure Assessment, OECD
Environment Monograph No.67, 1993.
· OECD Test Guidelines 107, 117
[2.6. A.] Water Solubility

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· Should always be stated, including gases if necessary,
excluding volatile substances and substances unstable in
water.
· Determinations should be made at or near 20°C. If
solubility/temperature dependence is>3% per °C, further
measurements should be made at 10°C above and below the
initially chosen temperature. If the substance is "insoluble"
in water, the detection limit of the analytical method should
be indicated.
· OECD Test Guideline 105

[2.6.B.] pH Value and pKa Value
· Where applicable, enter values for the dissociation
constant(s)and the conditions under which they were
measured.
· Dissociation constants are particularly important for acids,
bases and inorganic chemicals (and are normally known
calculated or measured).
· OECD Test Guideline 112
[2.12] Oxidation-Reduction Potential
· Where applicable, indicate the redox potential and the
conditions under which it was measured. This property is
generally more important for inorganic chemicals.
[2.13 A.] Adsorption/ Desorption to Soil
· Where applicable, indicate the adsorption/ desorption to
soil and conditions under which it was measured.
· This property is particularly important for inorganic
chemicals in cases where Log Pow is not useful in view of
the expected properties of the chemicals.
· OECD Test Guideline 106
3. ENVIRONMENTAL FATE AND PATHWAYS
[3.1.1] Photodegradation
· For photodegradation, an estimation is generally sufficient.
· Estimation of photodegradability (and hydrolysis) can be
based on reference documents, e.g., "An Assessment of Test
Methods for Photodegradation of Chemicals in the
Environment" (ECETOC Technical Report No.3) and
"Handbook of Chemical Property Estimation Methods"
(W.J. Lyman, W.J. Reehl, D.H. Rosenblatt (ed.), Handbook

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of Chemical Property Estimation Methods, McGraw-Hill,
New York, 1983.)
· OECD Test Guideline 113
[3.1.2] Stability in Water (Hydrolysis)
· Testing is generally required for hydrolysis unless adequate
data is already available. But consideration should be given
to the possibility of using estimation methods.
· Additional testing may be required for hydrolysis even if
data have been supplied, given consideration to:
- choice of test protocol;
- quality of data.
· When possible, the products of hydrolysis should be
identified.
· OECD Test Guideline 111
[3.2] Monitoring Data (Environment)
· Where available, indicate an overview of monitoring data
in the environment with specifications of conditions.
[3.3] Transport and Distribution between Environmental Compartments
including Estimated Environmental Concentrations and Distribution
Pathways
· Environmental concentration and important fate and
between pathways based on simple models, e.g., those in the
"Guidance for Initial Assessment of Environmental
Exposure" and "Compendium of Environmental Exposure
Assessment Methods for Chemicals" (OECD Environment
Monograph No.27) etc. should be described.
· In particular calculation of distribution of a chemical
between environmental compartments by a Fugacity Level I
model should be provided. (The diskettes which
accommodate global reference model (FUGMOD) and
other national models which have been distributed by the
Secretariat can be used for this purpose.)
[3.5] Biodegradation
· Testing is generally required, other than for gases, unless
adequate data is already available.
· Additional testing may be required even if data have been
supplied, given consideration to:
- choice of test protocol;

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- quality of data.
· OECD Test Guideline 301A-301F
· The feasibility of each OECD Test Guideline (301A-301F)
may be dependent on the physical-chemical
properties (e.g., stability in water), and the structure of the
test substance.
4. ECOTOXICITY
· Where aquatic tests are carried out on poorly soluble
substances at nominal concentration above the solubility
limit in the test medium, and no mortalities or effects are
observed, then the LC50, EC50 and NOEC should be
indicated as being above the stated solubility limit in the test
medium.
· For poorly soluble substances, it should also be clearly
stated whether solvents were used to enhance the solubility.
Testing at the solubility limit, without solvent, is preferred.
(*) For substances which decompose in water, LC50, EC50
and NOEC should be expressed in terms of the nominal
concentration of the tested substance.
[4.1] Acute/Prolonged Toxicity to Fish
· Testing is generally required if no adequate data is already
available.
· Additional testing may be required even if data have been
supplied, given consideration to:
- results from testing and calculations;
- quality of data.
· OECD Test Guideline 203 (*)
[4.2.A] Acute Toxicity to Aquatic Invertebrates (Daphnia)
· Acute testing is generally required if no adequate data is
already available.
· Additional testing may be required even if data have been
supplied, given consideration to quality of data.
· OECD Test Guideline 202, Part 1 (*)
[4.3] Toxicity to Aquatic plants e.g. Algae
· Testing is generally required if no adequate data is already
available.
· Additional testing may be required even if data have been
supplied, given consideration to quality of data.

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· OECD Test Guideline 201 (*)
[4.5.2] Chronic Toxicity to Aquatic Invertebrates (Daphnia)
· Chronic testing will be required if there is concern about
possible long-term effects in the aquatic environment.
· OECD Test Guideline 202, Part 2 (*)
[4.6] Toxicity to Terrestrial Organisms
· If significant exposure is expected in the terrestrial
environment compartment, appropriate terrestrial toxicity
tests should be performed.
· In determining whether significant exposure may be
expected in the terrestrial environment, the following should
be considered:
- the chemical has a potential for reaching the
terrestrial environment based on use and
transport patterns and disposal practices taking
into account all phases of the life cycle
combined with;
- physical-chemical properties indicate the
compound may be persistent, has a potential to
bioaccumulate or a major portion may partition
to the soil; or
- measured data indicate residues in soil, waste
water sludge or groundwater.
· In considering which terrestrial testing should be
undertaken, it should be taken into account that studies
should be appropriate to the receiving environmental
compartment (e.g., in the case of sewage sludge, toxicity to
earthworms and plants). In addition, attention should be
given to cross media considerations.
· Initially, a test should be performed on terrestrial
invertebrates and/or plants. The results of other tests may
indicate the need for avian toxicity tests.
· OECD Test Guideline 205-208 (*)
- 205: Avian Dietary Toxicity Test
- 206: Avian Reproduction Test
- 207: Earthworms Acute Toxicity Test
· The artificial soil test is preferred because the paper
contact test is not truly representative of the natural habitat.
- 208: Terrestrial Plants, Growth Test

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5. TOXICITY
[5.1] Acute Toxicity
· Testing is generally required if no adequate data is already
available. Consideration should be given to the possibility of
using data from analogues or repeated dose toxicity studies
on the same substance.
· Additional testing may be required even if data have been
supplied, given consideration to:
- test species;
- route of exposure;
- quality of data.
· The rat is the preferred species (oral and inhalation). For
dermal tests, the rat, rabbit or guinea pig are preferred
species.
· All substances, except gases and vapours, should be tested
by the oral route. Dependent upon the physical-chemical
properties of the substance and the most important route of
human exposure, the dermal or the inhalation route could
also be considered. Gases should be tested by the inhalation
route alone.
· OECD Test Guideline 401-403, 420
[5.4] Repeated dose Toxicity
· Testing is generally required if no adequate data is already
available.
· Additional testing may be required even if data have been
supplied, given consideration to:
- test species;
- route of exposure;
- duration of exposure;
- quality of data.
· The rat is the preferred species but consideration should be
given to the species used in the acute test. Oral, dermal and
inhalation routes should be considered. The oral route is
normally preferred. The appropriate route should be
selected dependent on physical-chemical properties of the
substance, the results of the acute toxicity tests and the most
important route of human exposure.
· OECD Test Guideline 407, 410 and 412
· The "Combined Repeated Dose Toxicity Study with the
Reproduction/Developmental Toxicity Screening
Test" (OECD Test Guideline 422) is also acceptable.

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[5.5] [5.6] Genetic Toxicity in vitro and in vivo
· Testing is generally required if no adequate data is already
available.
· Additional testing may be required even if data have been
supplied, given consideration to:
- test organism, strain and/or cell system;
- if metabolic activation has been used;
- quality of data.
· Two different endpoints should be tested: gene mutation
and chromosomal aberration. These endpoints may be
evaluated by using the following tests:
- Gene mutation in prokaryotic cells, should be performed
preferably in Salmonella typhimurium (OECD Test
Guideline 471). The chemical class of the test substance may
determine which test organism and whether modified
procedures may be needed. The test should be carried out
with and without metabolic activation.
- Chromosomal aberration in mammalian cells grown in
vitro (OECD Test Guideline 473) or in vivo methods such
as the micronucleus test or metaphase analysis of bone
marrow cells (OECD Test Guidelines 474, 475). For
chemicals which are in vitro mutagens and are handled and
used as if they were in vivo mutagens, then any further in
vivo tests may be considered for post SIDS assessment.
[5.7] Toxicity to Reproduction
· Testing is generally required if no adequate data is already
available.
· Additional testing may be required even if data have been
supplied, given consideration to:
- test species;
- duration of exposure;
- quality of data.
· For the reproduction toxicity endpoint,
- when a 90-day repeated dose study is available and is
sufficiently documented with respect to studying effects on
the reproductive organs and a developmental study is
available, the requirements for the reproduction toxicity
endpoint are satisfied;
- when either a 90-day or 28-day repeated-dose study is the
only repeated dose study available, it is recommended that
the reproduction/developmental toxicity screening test (e.g.

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OECD Test Guideline 421) be carried out in order to satisfy
the requirements for the reproduction toxicity endpoint; and
- when a 90-day repeated dose study is available and
demonstrates no effect on reproductive organs, in particular
the testes, then a developmental study (e.g. OECD Test
Guidelines 414) can be considered as an adequate test to
complete information on reproduction/developmental effect.
· OECD Test Guideline 415 - 416. The screening tests
[OECD Test Guideline 422: Combined Repeated Dose
Toxicity Study with the Reproduction/Developmental
Toxicity Screening Test, (for when repeated dose toxicity is
not available) and OECD Test Guideline 421:
Reproduction/Developmental Toxicity Screening Test (for
when repeated dose toxicity is available)] are also
acceptable.
[5.8] Developmental Toxicity/Teratogenicity
· Endpoint of developmental toxicity is generally required if
no adequate data is already available. See Toxicity to
Reproduction.
· OECD Test Guideline 414
[5.11] Experiences with Human Exposure (Work Place Exposure)
· Information on work place exposure such as;
- concentration of chemicals in the workplace
(manufacturing, maintenance and professional
use) and indoor environment,
- number of workers (in range or situations
including manufacture, maintenance and use),
- frequency, duration and level of exposure
should be mentioned if available.
· Effects of accidental or occupational exposure,
epidemiological and clinical studies, case reports, etc. can be
described.
3.5 Considerations Concerning the Adequacy of Data in the SIDS
***
General
1. Each National SIDS Contact Point must have the opportunity to
evaluate the quality of data in the SIDS for chemicals with complete
studies available for which they are responsible as a Sponsor country.
2. OECD Test Guidelines and GLP Principles are generally used to
produce studies of acceptable quality. However, data may be considered

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adequate for the purposes of screening even if not totally acceptable by
international standards (e.g. OECD Test Guidelines, GLP Principles).
This is best determined by expert judgement on a case-by-case basis.
3. It may not be necessary to conduct certain studies in cases when:
· other studies, for example on analogues, are available and
the results are consistent - e.g., acute toxicity studies,
biodegradation studies;
· there are other relevant studies or calculations available,
and the results are consistent, which diminishes the need for
retesting; and/or
· an approximate value is adequate for screening purposes,
e.g. acute toxicity studies.
4. If studies have been carried out according to guidelines other than
those of the OECD, these test methods should be clearly described. Also
if calculated data are reported, the method of calculation and its
justification should be described.
5. In the same way, if studies have not been carried out under the OECD
GLP Principles, an explanation for not doing so must be provided.
6. If some SIDS data are inadequate or missing, there will be a bias for
testing unless a rationale for not testing is provided and is accepted in the
international context. Again, bearing in mind animal welfare
considerations, internationally acceptable methods of in vitro testing
should be considered as a first line of approach.
7. Studies should be referenced as clearly as possible so that, when data
are prepared for transfer to IRPTC and IPCS, they can be properly
identified and coded.
Physical-chemical Data
8. Physical-chemical data for boiling point and melting point when taken
from reliable references (i.e. from handbooks) rather than taken from
actual test reports can generally be accepted because there is good
confidence in these data based on experience. Information on related
compounds may be useful in affirming physical-chemical parameters.
9. For vapour pressure, octanol/water partition coefficients (Pow) and
water solubility studies, more scrutiny may be required as such data are
more critical to the initial assessment of potential hazards, e.g.
bioaccumulation. In particular, calculated values of log Pow are not
reliable if greater than 6. The American MedChem database could be
used as a good source of data for these endpoints.
10. Key information which affects the value of physical-chemical
properties such as temperature and methods used must be provided.

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Environmental Fate Data
11. As for biodegradation data on a chemical, the most important issue
at the level of the SIDS is whether a compound is readily biodegradable
or not. Therefore, in any ready biodegradability test, the following
figures should be provided:
· the number of micro-organisms present;
· the time window for 10 per cent degradation; and
· the test results at the end of the test.
It is necessary to present these data for tests which are comparable with
ready biodegradation tests. Other biodegradation data that are available,
especially data obtained using natural media such as soil or river water,
should also be included in the SIDS dossier.
12. Distribution of a chemical between environmental compartments can
be calculated by the Fugacity Level I Model in the FUGMOD computer
program, which has been distributed by the OECD Secretariat and can
be obtained from SIDS Contact Points. Primarily partition coefficients
such as soil/water Koc, Henry's constant and BCF's are required for
inputting into the fugacity model when it is used.
Ecotoxicity and Toxicity Data
13. If any of the required ecotoxicity or toxicity studies are lacking,
consideration may be given to waiving some testing endpoints where
there are adequate data for closely related analogues. This should be
closely scrutinised on a case-by-case basis.
14. For a proper evaluation of ecotoxicity and toxicity studies, detailed
information should be reported in addition to those explicitly required in
the Revised OECD HPV Form 1 or the HEDSET. Lack of detail in
reporting toxicity or ecotoxicity data does not automatically lead to the
need to re-test, but this will delay a decision on the acceptability and
adequacy of toxicity and ecotoxicity studies mentioned in the SIDS
Dossiers. Availability of detailed information for all tests make the
review by other countries much easier and more efficient. Examples of
details on the information on the aquatic toxicity tests which could be
reported, if available, recommended by the Netherlands and the US
respectively, are attached as an Annex to this section.
15. If the data presented from studies not fully in compliance with GLP
Principles and/or not conducted according to internationally acceptable
test guidelines suggest a very low concern for the desired endpoints, i.e.
a high and acceptable NOEL, then the test may be considered adequate
for screening purposes.
***The content of this section is based on a document discussed at the 20th Joint Meeting of the Chemicals

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Group and Management Committee of the Special Programme on the Control of Chemicals (May 1993).

Annex

Information to be Used in the Evaluation of Aquatic Toxicity Test
Results, if available
1. Items and Contents Recommended by the Netherlands
A. Organism
B. Method
C. Test-system: static; semi-static; continuous flow
D. Test result:
-- fish: 24 + 48 + 72 + 96 hour
-- daphnia/acute: 24 + 48 hour
-- algae: 24-72 hr: EC50 + NOEC + parameters used;
biomass or growth rate
-- daphnia/chronic: NOEC, LC50(21d), EC50(21d) (in
cases where chronic data are needed)
E. Purity of test compound
F. Whether analysis has been carried out and if so:
-- Is the result based on the nominal or measured
concentration?
-- If the result is based on the measured concentration, an
indication of the discrepancies should be given.
G. Additional information for special compounds:
(This information also is required for biodegradation tests.)
-- volatile substance: was an open or closed system used?
-- insoluble substance: if a solvent is used, how much has
been added and has a solvent control been carried out?
2. Items and Contents Recommended by the US
A. Organism:
Age, mean length and mean weight, as appropriate; loading.
B. Test System:
For semi-static, time period between renewal; for continuous flow,
number of replacements per day.
C. Fish Test Result:
24, 48, 72 and 96 hr results; discriminate between intrinsic (chemical)
toxicity and physical toxicity; sub-lethal effects observed.

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D. Daphnia Test Result (acute):
24 and 48 hr result; discriminate between intrinsic (chemical) toxicity and
physical toxicity; sub-lethal effects observed.
E. Algae Test Result:
24-72 hr (96 hr EC50, if available); NOEC and LOEC; parameter used
(biomass or growth rate).
F. Analytical Method:
Detection limit, mean per cent recovery, table of nominal concentrations
and measured concentrations withtime interval(s) indicated, mean
measured concentrations, statement as to how concentrations below the
detection limit were handled in the calculation of mean measured
concentrations; concentration values should be reported as "100% active
ingredient."
G. Dilution Water:
Source, hardness, pH, total organic carbon (TOC), total suspended
solids (TSS).
H. Algae Growth Medium:
Composition; final concentrations of nutrients in medium; TOC;
hardness.
I. pH of Test Solution:
pH of test solution at t=0 hr and 48 hr or 96 hr as appropriate.
J. Purity:
Impurities; physical state.
K. Aeration:
Was aeration used during test; if yes, how much and by what method?
L. Volatile:
For closed systems, presence of head space; size of any head space;
modifications of closed test system relative to open test system, e.g.
adjustments in algal growth medium of bicarbonate concentration.
M. Stock Solution Preparation:
(1) If a stock solution was prepared, this procedure must be
carefully evaluated using considerations such as the
following: check all calculations from test material to stock
solution; concentration to treatment concentrations; indicate
clearly if stock solution concentration was based on test
material "as is" or on 100 percent active ingredients;
solvents or carriers used and their possible effects;
concentration of solvents or carriers used; pH of stock

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solution; pH adjustment, if any; time between stock solution
preparation and addition of organisms to exposure vessels;
observations of physical appearance of stock solution: clear,
milky dispersions as observed for detergents and charged
polymers, dispersed solids, precipitate, oily slick or phase
separation, etc.; if precipitates are present, how were they
handled: mixed and distributed to exposure vessels of
filtered out; if filtered out, what type of filter, were all solids
filtered or only part of solids; was only the water soluble
fraction (WSF) removed from the stock solution; methods
used to dissolve test material: sonication (how long), mixing
time heating, etc.
(2) If no stock solution was prepared, the direct dilution of
test material was employed. What was the time between
direct dilution of the test material to the exposure vessel and
the addition of organisms?
[Note: Not all of these points are of equal relevance to the
evaluation of tests, depending on the nature of the specific
chemical. Guidance could be developed as to when certain
information is critical to interpreting study results on a given
class of chemicals in later phases of the HPV programme.]

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