Y. Ikenaga, Y. Sakuratani
National Institute of Technology and Evaluation (NITE), Tokyo, Japan

Introduction

OMaterials and Methods

The BCF test data for 549 low-molecular-weight existing chemicals2) and 201
new chemicals(notification period: Apr. 2007 – Sep. 2013) obtained under theChemical Substances Control Law in Japan were used for the analysis.
The BCFH (the BCF value in the high test concentration) and the BCFL (the BCFvalues in the low test concentration) in the data set were compared.

Results and Discussion

SnOHNHOO123OH

45
4

logBCFL [-]In the OECD Test Guideline 3051) for evaluating bioconcentration factor (BCF)
for fish, it has been recommended to evaluate BCF by using two test
concentrations. Recently, the test guideline “Aqueous Exposure Bioconcentration
Fish Test (305-I)” was revised on October 2012 when adding new method“minimized aqueous exposure fish test (305-II)” in order to reduce the number oftest fish from a viewpoint of animal protection. When it is determined that theysatisfy government-imposed standard, BCF is evaluated by using one test
concentration data. So it is necessary to determine the standard criteria.
In this study, we investigated the applicability of one concentration BCF test byanalyzing the concentration dependence of the bioconcentration factor for fish.

O●：outliner (4 chemicals)○：others (320 chemicals)

3
322 1

41
0-1-1012

345logBCF [-]logBCFL [-]HFor more than 26.4% of existing chemicals, BCFL were more than twice BCFH
Fig.1
logBCF
vs.
logBCFplot.
(324 existingHLvalue (Fig.1,2). However, for 342 existing chemicals that were tested in thechemicals
thatweretestedin theconcentration lower than its water solubility and with BCF≥100, the differences
concentration
lowerthanitswater solubility)
between BCFH and BCFL were 1.2% (Fig.1). Only 4 chemicals (No.1-4) with BCFL
5
more than 100 showed the difference (BCFL - BCFH) more than double. For the 3logBCFL =logBCFH +0.3
chemicals (No.2-4) out of the 4 chemicals some concerns on the accuracy of4
determination were found when we checked the test report. Therefore, only one
case, Tetrabutyl- Stannane (No.1, BCFH=68, BCFL=219, BCFL/BCFH=3.2), tends tohave higher BCFL value than other chemicals by factors other than the error of3measurement. We need to pay attention for this case. Because the organotin
compound has a protein binding, its bioconcentraion potential may become higher.
2
Similarly, we compared BCFL with BCFH in 201 new chemicals that weretested in the concentration lower than its water solubility and with BCF≥100 (Fig.3).
1
The differences for more than double between BCFH and BCFL were only 3logBCFL =logBCFH -0.3chemicals (No.5-7). For the these 3 chemicals, it is assumed to be the influence of＊logBCF = 0.30(BCF = about two times)
the adsorption in bioconcentration of chemicals when we checked the test report.
And it is found that No.6 is a perfluorochemical and a surfactant.
-1
From these results, METI (Ministry of Economy, Trade and Industry)
-1
012
345
announced on June 2014 that the BCF value measured by using one testlogBCFH [-]concentration data can be submitted in the registration of new chemicals under theFig.2 logBCFH vs. logBCFL plot.
CSCL. However, it is applied in the following conditions:(Other 225 existing chemicals)

305-II test data:

1. The test concentration is less1.
than one-tenth of its watersolubility.
2.
2. The test measurement is aconcentration of the lowest
possible level.
3.
3. BCFss (the steady-statebioconcentration factor) ismeasured, and the value is lessthan 500.
4.
4. It excepts for inorganic metallic
compounds, organic metallic
5.
compounds, surfactants,
6.
perfluorochemicals andmulticomponent mixture.
7.

5

The test concentration is less than one-tenth●：outliner (3 chemicals)of its water solubility.
○：others (198 chemicals)
4
The test concentration and the fish
5
concentration is more than 10 times for a63
determination limit of measurement devices.
A chemical is not achieved during uptake,7
provided that uptake and depuration act
2approximately according to first order kinetic
No.6:
processes.
1BCFk (the kinetic bioconcentration factor) is・Perfluorochemicalmeasured, and the value is less than 200.
and0BCFk ≥ Minimised BCFss・Surfactant
Limited to a chmical whose logPow is less than-1-1012345six.
It excepts for inorganic metallic compounds,
logBCFH [-]organic metallic compounds, surfactants,
Fig.3 logBCFH vs. logBCFL plot. (201 new
perfluorochemicals and multicomponent
chemicals that were tested in themixture.

logBCFL [-]305-I test data:

concentration lower than its water solubility )1) OECD Test Guideline 305: http://www.oecd-ilibrary.org/environment/test-no-305-bioaccumulation-in-fish-aqueous-and-dietaryexposure_9789264185296-en
2) J-CHECK (Japan CHEmicals Collaborative Knowledge database): http://www.safe.nite.go.jp/jcheck/top.action