N-(1,3-Dimethylbutyl)-N

OECD SIDS
N-(1,3-DIMETHYLBUTYL)-N´-PHENYL-1,4-PHENYLENEDIAMINE
Table 4 Stability of 6PPD in water (IUCLID 3.1.2)
Parameter Method Result Source
Stability of 4-ADPA in
water
Stability of 4-ADPA in
water
Stability of IPPD in
water
Stability of 6PPD in
water
Stability of 6PPD in
water
Stability of 6PPD in
water
Degradation of 6PPD in
pure and environmental
water
Aqueous test solutions
under aerobic or
anaerobic conditions,
similar to OECD TG
111
OECD TG 111
Deionized water under
aerobic conditions
4-ADPA abiotic degradation dependent
on oxygen, heavy metals, and light.
Estimated half lives at 50 °C: destilled
water, anaerobic, darkness > 50 h;
destilled water, aerobic, darkness 26 h;
destilled water, aerobic, light 22 h;
nutrient medium containing traces of
heavy metals such as Mn, Co, Cu, Mo,
and Zn, aerobic, light 7 h.
4-Hydroxydiphenylamine identified as
degradation intermediate
4-ADPA half lives:
80 h at pH 4
57 h at pH 7
5 h at pH 9
IPPD degraded 99 % within 24 h
N-Phenylbenzoquinone imine and 4-
Hydroxydiphenylamine identified as
degradation intermediates
Bayer AG 2002a
Bayer AG 2002b
Monsanto 1992
Aerated water 6PPD half life less than 1 d Monsanto 1979a
sterile and deionized
water/sterile
Mississippi river water.
Aqueous solutions
Aqueous test solutions
under aerobic
conditions, test design
similar to OECD TG
111
6PPD half lives were 6.8 h in sterile and
deionized water, and 3.9 h in sterile
Mississippi river water containing traces
of heavy metals
6PPD stable for weeks at pH 2 in the cold,
but degraded within a few hours at neutral
or basic pH
In buffered aerobic solution at 50 °C the
half life of 6PPD is about 5 h,
at 26 °C it is about 14 h.
In the presence of traces of heavy metals
such as Mn, Co, Cu, Mo, and Zn, the half
life decreased significantly.
4-Hydroxydiphenylamine was the major
aromatic intermediate of 6PPD
degradation
Monsanto 1981
Kretzschmar and
Neyen 1992
Bayer Industry
Services 2003
2.2.4 Transport between Environmental Compartments
According to the Mackay Fugacity Model Level I, the main target compartment for 6PPD is soil (95
%), followed by water (2 %) and sediment (2 %, Table 5, Bayer AG 2003b). However, due to rapid
degradation (cf Chapters 2.2.3 and 2.2.5), the level 1 fugacity modelling has to be applied with
caution. The degradation product of 6PPD and its analogues, 4-hydroxydiphenylamine is more
soluble in water (water solubility 170 mg/l, log Kow = 2.46,) than 6PPD (EPA 2004). It is also
neither stable in the atmosphere (t ½air = approximately 1 h) (EPA 2004) nor in aquatic media (cf
Chapter 2.2.3).
UNEP PUBLICATIONS 13