Publication Details |
| Category | Text Publication |
| Reference Category | Journals |
| DOI | 10.1016/j.ecoenv.2026.120082 |
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| Title (Primary) | Abiotic transformation of radiolabelled 6-PPD and 6-PPDQ in water and in presence of nitrogen/air/ozone and light |
| Author | Reemtsma, T.; Seiwert, B.; Yeomans, P.; Mumford, R.; Bennett, S. |
| Source Titel | Ecotoxicology and Environmental Safety |
| Year | 2026 |
| Department | EAC |
| Volume | 315 |
| Page From | art. 120082 |
| Language | englisch |
| Topic | T9 Healthy Planet |
| Supplements | Supplement 1 |
| Keywords | Tire abrasion; Leaching; Persistence; Photolysis; Aging |
| Abstract | N-(1,3-Dimethylbutyl)-N′-phenyl-p-phenylendiamine
(6-PPD) and one of its oxidation products, 6-PPD quinone (6-PPDQ) are
environmental contaminants released from tire and road wear particles
(TRWP). The abiotic transformation of both compounds by hydrolysis and
in contact with atmosphere with and without oxygen species and simulated
sunlight was studied, following relevant portions of OECD-guidelines
111 and 316, and using radiolabelled test substances. This allowed for
mass balances including transformation products, those identified by
liquid chromatography-mass spectrometry and those remaining
unidentified. 6-PPD was effectively degraded by hydrolysis at neutral
and basic pH (DT50 5 – 12 h at 25°C), with 4-HDPA being the major
reaction intermediate. 6-PPDQ remained below 0.2% of the applied
radioactivity (AR) of 6-PPD, except at very acidic conditions and low
temperature (10°C) with an intermediate yield of 7.5% AR. In contact
with atmosphere 6-PPD was transformed by direct photolysis (DT50 14 h).
Direct reaction with ozone was slow (DT50 3.5 d) but degradation by
OH-radicals (ozone/light) was very fast (DT50 3.7 h). A diverse set of
products was formed; 6-PPDQ was determined in some cases, with a maximum
intermediate yield of 1.3% AR and decreasing again with ongoing
oxidation of 6-PPD (to levels ≤ 0.6% AR with ongoing oxidation). 6-PPDQ
is not susceptible to pure hydrolysis (DT50 > 1000 d at pH 7, mean
490 d in 13 natural waters) and very limited to direct photolysis (DT50
56 d). On the contrary, reactivity towards reactive oxygen species
(air/ozone and light) is in the same range as for 6-PPD (DT50 2 – 7 h).
Oxidative transformation of 6-PPDQ proceeds via opening of the
quinone-ring, with 20–50% AR recorded as CO2 within 2 d. For 6-PPDQ oxidation in the presence of light only 50 – 80% of AR could be recovered. This study with 14C-labelled
test substances provides solid information on the abiotic
transformation of both, 6-PPD and 6-PPDQ, and supports environmental
risk assessment. |
| Reemtsma, T., Seiwert, B., Yeomans, P., Mumford, R., Bennett, S. (2026): Abiotic transformation of radiolabelled 6-PPD and 6-PPDQ in water and in presence of nitrogen/air/ozone and light Ecotox. Environ. Safe. 315 , art. 120082 10.1016/j.ecoenv.2026.120082 |
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