Registration Dossier

Administrative data

Endpoint:
hydrolysis
Type of information:
other: OECD SIDS
Adequacy of study:
other information
Reliability:
other: OECD SIDS
Rationale for reliability incl. deficiencies:
other: no reliability is given as this is a summary entry for the OECD SIDS

Data source

Referenceopen allclose all

Reference Type:
secondary source
Title:
Phthalimide - CAS No: 85-41-6
Author:
OECD SIDS
Year:
2005
Bibliographic source:
SIDS Initial Assessment Report for 20th SIAM, UNEP Publications
Reference Type:
study report
Title:
Unnamed
Year:
1999
Reference Type:
publication
Title:
Unnamed
Year:
1993
Reference Type:
publication
Title:
Effects of light on the organophosphorus fungicide ditalimfos and two degradation products examined in rainwater and on soil surface in a long-term study
Author:
Allmaier GM and Schmid ER
Year:
1986
Bibliographic source:
Bodenkultur 37 (2), 177-186
Reference Type:
publication
Title:
Kinetics and equilibrium in the ammonolysis of substituted phthalimides
Author:
McClelland RA, Seaman NE, Duff JM, and Branston RE
Year:
1985
Bibliographic source:
Can. J. Chem. 63, 121-128

Materials and methods

Principles of method if other than guideline:
OECD SIDS
GLP compliance:
not specified

Test material

Constituent 1
Chemical structure
Reference substance name:
Phthalimide
EC Number:
201-603-3
EC Name:
Phthalimide
Cas Number:
85-41-6
Molecular formula:
C8H5NO2
IUPAC Name:
1H-isoindole-1,3(2H)-dione

Results and discussion

Any other information on results incl. tables

OECD SIDS (2005):

 

The stability of phthalimide in water was investigated with the method OECD TG 111 in buffered solution, at different pH values. The initial test concentration was 10 mg/l; each experiment was conducted twice at different test temperatures. The pH conditions of the test medium affected significantly the hydrolysis rate of phthalimide in water. At 25 °C, the half-life was 115 days at pH 4, 57 hours at pH 7, and 1.1 hours at pH 9 (CITI, 1999). Hydrolysis products were ammonia and phthalic acid, formed via phthalamic acid as an intermediate. (MITI, 1993).

Consistently, Allmaier and Schmid (1986) observed that phthalimide released during the degradation of ditalimfos (CAS 5131-24-8) was degraded in rainwater (pH 5.9) in complete darkness and under artifical light. Phthalimide reached its maximum concentration after 12-24 days, and was completely removed after 48-96 days. The authors assumed that hydrolysis (and photolysis) contributed to degradation of phthalimide in aqueous systems, but unfortunately, these experiments were not designed to distinguish between abiotic and biotic degradation (Allmaier and Schmid, 1986).

McClelland et al. (1985) observed the hydrolysis of phthalimide in different buffered solutions with different pH conditions: sodium hydroxide solution at pH > 11, carbonate buffer at pH 8.5-11, and phosphate buffer at pH 7.8-8.5. Phthalimide initial concentration was = 10-3 mol/l. Based on the obtained results McClelland et al. extrapolated two hydrolysis rates (k2,k3) for a theoretical diluted buffered solution at 1 M ionic strength, and 25 °C: k2= 4.8 l/mole s and k3= 8.5 l/mole s corresponding to different hydrolysis steps. The half-lives of phthalimide obtained by graphic extrapolation are approximately 1.3 days at pH 7 and 2.8 hours at pH 8. Hydrolysis products were ammonia and phthalic acid, formed via phthalamic acid as an intermediate.

McClelland et al. (1985) also investigated the ammonolysis of phthalimide and concluded that the ions nitrite and ammonium catalyzed the degradation process. Phthalamide was the ammonolysis product. However, the concentrations (NH3/NH4+:1 mol/l) applied in the experiments are not relevant for the environment.

 

Hydrolysis of phthtalimide:

 

Procedure

Result

Reference

OECD TG 111

t½  pH 4 = 115 d (25 °C)
t½  pH 7 =   56.7 h (25 °C)
t½  pH 9 =     1.1 h (25 °C)

CITI, 1999

Basic buffer solutions, UV-Spectrometry

Derived rate constants for the base-catalyzed hydrolysis:
k2= 4.8 l/mole-sec
k3= 8.5 l/mole-sec
Half-life (extrapolated from the graph):
t1/2= 1.3 d at pH 7
t1/2= 2.8 h at pH 8

McClelland et al., 1985

 

 

 

 

Applicant's summary and conclusion