3,3'-methylenebis[5-methyloxazolidine]

Hydrolysis

Administrative data

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The study was considered reliable without restriction as the study design is comparable to OECD Guideline 111 and a quality assurance statement is provided. Deficiences in comparison to OECD guideline 111: The purity of the applied test material (b.p. CONTRAM™ MBO) was not determined. The pH-values of the test samples were not measured during and after the test. Sterilization of test samples and glassware was not performed. No helium, nitrogen or argon bubbling of test samples was performed for avoiding oxygen. The time dependence of hydrolysis is only partially reported (e.g. time of measurement not given, adjustment of equilibrium reported instead of precise points of time). The pH- dependence of the aqueous hydrolysis of Reaction product from paraformaldehyde and 2-hydroxypropylamine (ratio of 3:2) was investigated using 1% w/w aqueous solutions. This concentration is considered to be too high in comparison to environmentally relevant concentrations. OECD guideline 111 recommends sample concentrations below 10-2 M for investigating pH-dependence and hydrolyisis under environmentally relevant conditions. The study doesn’t report how the samples were kept at temperature (20°C, 25°C) and the accuracy of the applied method. The limits of detection (LOD) and quantification (LOQ) of the analytical methods are not reported.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Deviations:

not applicable

GLP compliance:

no

Remarks:

Study follows quality assurance standards

Test material

Test material information

Constituent 1

Reference substance name:

3,3'-methylenebis[5-methyloxazolidine]

EC Number:

266-235-8

EC Name:

3,3'-methylenebis[5-methyloxazolidine]

Cas Number:

66204-44-2

Molecular formula:

C9H18N2O2

IUPAC Name:

3,3'-methylenebis[5-methyloxazolidine]

Details on test material:

- Test material: Reaction products of paraformaldehyde and 2-hydroxypropylamine (ratio of 3:2)
- Lot/Batch number: BC 6120
- Specification: CONTRAM™ MBO

Study design

Analytical monitoring:

yes

Buffers:

- Buffer solutions:
Acetate buffer (pH 4.0) - 5.0 mL 1N acetic acid and 81.6 mg sodium acetate were dissolved in 50 mL purified water.
Phosphat buffer (pH 7.0) - 680 mg potassium dihydrogen phosphate and 2.98 mL 1M sodium hydroxide were dissolved in 50 mL purified water.
Borate buffer (pH 9.0) - 618 mg boric acid and 3.98 mL 1M sodium hydroxide were dissolved in 50 mL purified water.
- Solutions for determination of the concentration-dependent composition by 13C-NMR: 0.0025%, 0.025%, 0.25%, 1.00%, 10.00% and 50.00% (v/v) of the test substance in D2O.
- Investigation of hydrolysis: 1% (w/w) solutions of the test substance in H2O at pH 4.0, 7.0 and 9.0.

Details on test conditions:

- Test system: 5 mm NMR tubes
- Temperature: 25°C (concentration-dependent composition); 20°C (reaction rate)

Duration of test

Duration:

8 h

Results and discussion

Transformation products:

yes

Identity of transformation products

Identity of transformation products 1

No.:

#3

Reference

Reference substance name:

Unnamed

IUPAC name:

1-aminopropan-1-ol

CAS number:

25154-49-8

Molecular formula:

C3H9NO

Molecular weight:

75.11

SMILES notation:

CCC(N)O

InChl:

1S/C3H9NO/c1-2-3(4)5/h3,5H,2,4H2,1H3

Identity of transformation products 2

No.:

#2

Reference

Reference substance name:

Unnamed

IUPAC name:

2-aminopropan-1-ol

Inventory number:

InventoryMultipleMappingImpl [inventoryEntryValue=EC 228-207-3]

CAS number:

6168-72-5

Identity:

1-Propanol, 2-amino-

Molecular formula:

C3H9NO

Molecular weight:

75.11

SMILES notation:

CC(N)CO

InChl:

InChI=1/C3H9NO/c1-3(4)2-5/h3,5H,2,4H2,1H3

Identity of transformation products 3

No.:

#1

Reference

Reference substance name:

Unnamed

IUPAC name:

methanediol

Inventory number:

InventoryMultipleMappingImpl [inventoryEntryValue=EC 207-339-5]

CAS number:

463-57-0

Molecular formula:

CH4O2

Molecular weight:

48.041

SMILES notation:

OCO

InChl:

InChI=1/CH4O2/c2-1-3/h2-3H,1H2

Details on hydrolysis and appearance of transformation product(s):

The results show that components of the substance exist in an equlibrium which depends on the dilution in D2O. The relative amounts of MBO and different hydrolysis products are given the table below. With proceeding dilution the amount of N,N’-methylene-bis-(5-methyloxazolidine) and N-methylol-5-methyloxazolidine decreases and the amount of hexahydro-1,3,5-tris(2-hydroxypropyl)-s-triazine (up to a dilution of 1%) and of 5-methyl-oxazolidine increases (up to a dilution of 0.25 %). With further dilution the concentration of the latter compounds is strongly reduced due to hydrolysis. At the same time the hydrolysis products formaldehyde hydrate and the aminopropanols are formed.

Dissipation DT50 of parent compound

Remarks on result:

not determinable

Remarks:

The half life time of hydrolysis can not be calculated because the test item is not a single compound but a mixture. Hydrolysis is very fast and starts already during the first 13C NMR measurements.

Details on results:

- The half life time of hydrolysis can not be calculated because the test item is not a single compound but a mixture. Hydrolysis is very fast and starts already during the first 13C NMR measurements.

Any other information on results incl. tables

Relative amounts of MBO and different hydrolysis products:

 

Compound	CONTRAM™ MBO in D2O
	100% (v/v)	50% (v/v)	10% (v/v)	1% (v/v)	0.25% (v/v)	0.025% (v/v)	0.0025% (v/v)
	^13C signal area					^1H signal area
MBO	10.6660	1.8960	0.2050	0.0037	0	0	0
triazine (HPT)	1.9860	4.7340	1.2010	0.1320	0.0173	0.162	0
MMO	1.8240	0.3490	0.0260	0	0	0	0
5-methyl­oxazolidine (MO)	0.9820	1.0560	0.2470	0.0320	0.0176	3.298	0.12
2-amino­propanol(1) (2-AP)	0	0	0	0	0	0.323	0
1-amino­propanol(2) (1-AP)	0	0	0	0	0	3.617	2.318
formaldehyde hydrate (FAH)	0.0360	0.1230	0.0760	0.0180	0.0072	2.099	1.032
further unknown compounds	4.1240	1.8060	0.206	0	0	0	0
total signal area	19.6180	9.9640	1.9610	0.1857	0.0421	9.499	3.47

 

Compound	CONTRAM™ MBO in D2O
	100% (v/v)	50% (v/v)	10% (v/v)	1% (v/v)	0.25% (v/v)	0.025% (v/v)	0.0025% (v/v)
	signal area/total signal area
MBO	0.5437	0.1903	0.1045	0.0199	0	0	0
triazine (HPT)	0.1012	0.4751	0.6124	0.7108	0.4109	0.0170	0
MMO	0.0930	0.0350	0.0133	0	0	0	0
5-methyloxa­zolidine (MO)	0.0501	0.1060	0.1260	0.1723	0.4181	0.3472	0.035
2-aminopro­panol(1) (2-AP)	0	0	0	0	0	0.0340	0
1-aminopro­panol(2) (1-AP)	0	0	0	0	0	0.3808	0.6680
formaldehyde hydrate (FAH)	0.0018	0.0123	0.0388	0.0969	0.1710	0.2210	0.2974
further unknown compounds	0.2102	0.1813	0.1050	0	0	0	0

 

 

Formaldehyde releases from 1% solution as function of pH:

 

pH 4		pH 7		pH 9
time [h]	% H2CO	time [h]	% H2CO	time [h]	%H2CO
0.33	38.27	0.33	25.83	0.33	7.18
0.92	39.48	0.92	27.00	0.92	7.48
2.10	41.35	2.10	27.15	2.10	8.39
3.67	41.71	3.67	27.65	3.67	9.20
5.23	41.76	5.23	28.67	5.23	9.10
6.80	41.66	6.80	28.82	7.58	9.05

Applicant's summary and conclusion

Conclusions:

The study clearly demonstrates hydrolysis of the substance. At concentrations which are applied in the media of exotoxicity tests or are expected in the environment, the substance is completely hydrolysed.

Executive summary:

The composition of solutions of the substance in D2O was found to be strongly dependent on the concentration. While at 100% MBO was the main component, its content decreased with higher dilutions and was absent at 0.25%. The content of α, α′, α″-trimethyl-1,3,5-triazine-1,3,5(2H,4H,6H)-triethanol (HPT) increased up to a dilution of about 1%, but decreased at further dilution. Formaldehyde and 5-methyloxazolidine were identified as products of hydrolysis, the content of both compounds increased when dilution increased. At the highest dilution (0.0025%, i.e. 25 mg/l), the substance was almost completely hydrolysed to formaldehyde hydrate and 2-propanolamine.

The test results reveal that at concentration levels being applied in the media of ecotoxicity tests or being expected in the environment, the substance is completely hydrolysed.

The reaction rate of hydrolysis was determined at different pH values via measurement of the formaldehyde being released. It was found that at pH 4 and 7 the formaldehyde content reached a plateau after ca. 1-2 hours, while at pH 9 the reaction was slightly slower, reaching the plateau after 3-4 hours.