N-isopropyl-N'-phenyl-p-phenylenediamine

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Assessment of PBT/vPvB Properties - Comparison with the Criteria of Annex XIII

PBT and vPvB criteria and the corresponding properties of IPPD

Criterion	PBT criteria	vPvB criteria	property	Criterion fulfilled?
P	Half-life in marine water > 60 d, or half-life in fresh- or estuarine water > 40 d, or half-life in marine sediment > 180 d, or half-life in fresh- or estuarine water sediment > 120 d, or half-life in soil > 120 d	Half-life in marine, fresh or estuarine water > 60 d, or Half-life in marine, fresh or estuarine sediment > 180 d, or half-life in soil > 180 d	Not readily biodegradable, half-life in water: 3.9h	Preliminary no
B	BCF > 2000	BCF > 5000	Not B not vB	no
T	Long-term NOEC for marine or freshwater organisms < 0.01 mg/l	Not applicable.	21d-NOEC 0.028 mg/l for daphnia	no
T	CMR	Not applicable.	Not classified as CMR	no
T	Other evidence of chronic toxicity, as identified by the classifications: T, R48, or Xn, R48 according to Directive 67/548/EEC	Not applicable	Not classified as T, R48, or Xn, R48 according to Directive 67/548/EEC	no

 

8.1.1. Persistence Assessment

IPPD is not readily biodegradable with 18.9 % biodegradation in 28 days (Monsanto 1979). However, it hydrolyses rapidly with a half-life of 3.9 hours at pH7. Hence it is classified as preliminary not persistent. The primary hydrolysis products 4 -HDPA and p-Benzoquinoneimine-N-phenyl are more stable in hydrolysis tests and biodegradation does not appear to occur. For these reasons these metabolites are considered as preliminary persistent.

8.1.2. Bioaccumulation Assessment

Measured bioconcentration factors (BCF) for IPPD are not available. A QSAR yield a BCF of 31.2 indicating that the substance is far below the trigger value of 2000. IPPD hydrolyses rapidly in the presence of water with a half life of approximately 3.9 hours.
The substance is not persistent in water due to the rapid hydrolysis. Therefore it is not bio-available. Possible hydrolysis products are less lipophilic. On the basis of these information it is not expected that bioaccumulation of IPPD occurs. The main hydrolysis products are 4-Hydroxydiphenylamine and p-Benzoquinoneimine-N-Phenyl and Isoproyplamine. The first 2 compounds are regarded to be similar as they reflect different oxidised forms of the same compound.
Bioconcentration factors of 4-Hydroxydiphenylamine and p-Benzoquinoneimine-N-phenyl

were determined according to OECD Guideline 305 C. The bioconcentration factor ranges from 1.2 - 49 . Therefore the B and vB criterion is neither fulfilled for the parent compound nor for the hydrolysis products.

8.1.3. Toxicity Assessment

There is one long-term aquatic toxicity test available (for algae). Additionally a chronic daphnia test is available for the primary hydrolysis product 4 -HDPA, yielding the key result of NOEC = 0.028 mg/L. Furthermore, the substance is not classified as carcinogenic, mutagenic or toxic for reproduction or R48. For these reasons, the substance does not meet the T-criterion.

8.1.4. Summary and overall Conclusions on PBT or vPvB Properties

A substance only is identified as a PBT substance if it fulfils all criteria described above According to information summarized above, the T criterion was fulfilled and the P criteria was preliminarily fulfilled. Hence IPPD is not PBT. Furthermore, the two primary metabolites 4 -HPDA and p-Benzoquinone-N-phenyl are also not PBT.

A substance only is identified as a vPvB substance if it fulfils both vPvB criteria described above.
The P criterion is preliminarily fulfilled, the B criterion is not fulfilled. Therefore, IPPD is not vPvB.