1,2,3-trichloropropane

Phototransformation in water

Link to relevant study record(s)

Reference

Endpoint:

phototransformation in water

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The study deviates from the OECD Guideline No 316. However, it gives evidence that photodegradation of 1,2,3-trichloropropane in water can occur under environmental conditions. The methods and results of the study are documented in sufficient detail to consider the study reliable with restrictions.

Study type:

direct photolysis

Principles of method if other than guideline:

Test solutions (10 mL) were irradiated with a mercury vapour light emitting wave lengths between 185nm to 360 nm. Test solutions were placed around the lamp in quartz or pyrex tubes. The density of the radiation at the level of the tubes was 1.27 MW/cm2. Low concentrations were used to study the rate constant for photolysis, whereas high concentrations were used to study to degradation products. Chemical analyses were performed by gas chromatography.

GLP compliance:

not specified

Radiolabelling:

no

Analytical method:

gas chromatography

Details on sampling:

A set of tubes with the same solution was placed around the lamp. One tube was sacrificed at set time intervals and the content was directly injected into the chromatograph.

Buffers:

no data

Light source:

other: Hanovia UV with mercury vapour

Light spectrum: wavelength in nm:

185 - 360

Details on light source:

no filters applied

Type of sensitiser:

OH radical

Details on sensitiser:

hydrogen peroxide

Concentration of sensitiser:

0 - 0.5 other: mol/L

Type of sensitiser:

other: methyl and acetyl radical

Details on sensitiser:

acetone

Concentration of sensitiser:

0 - 0.007 other: mol/L

Details on test conditions:

Samples were dissolved in demineralised water and placed in quartz or pyrex tubes on samplers turning around the lamp.

Duration:

5 d

Temp.:

25 °C

Initial conc. measured:

0 mol/L

Reference substance:

no

Dark controls:

no

Computational methods:

no data

DT50:

> 840 min

Predicted environmental photolytic half-life:

It is observed that the rates of photolysis in water are very slow which is foreseeable due to the weak absorption of radiation beyond 290 nm. On the other hand, photodegradation in natural waters may be accelerated by the presence of photocatalysts (titanium oxide, zinc oxide), photooxidants (like hydrogen peroxdide) or photosensitisers (like riboflavine, acetone). This is also indicated by the faster photodegradation observed in experiments performed with hydrogen peroxide or acetone in addition to the solution of the test substance.

Transformation products:

no

Validity criteria fulfilled:

yes

Conclusions:

The direct photolysis of 1,2,3-trichloropropane diluted in pure water was studied for wave lengths between 185 and 360 nm generated by a UV lamp. Rates of photolysis were low and the half-life was considerably greater than 840 minutes.

Executive summary:

The photolysis of 1,2,3-trichloropropane in pure water was studied using a UV lamp generating light in the wave length spectrum from 185 to 360 nm. The rate of photolysis was determined in four experiments. Ten mL of test solution at a low concentration were exposed to UV light in quartz or pyrex tubes arranged around the lamp. The concentration of the substance was measured at set time intervals by gas chromatography. The half-life for photodegradation of 1,2,3-trichloropropane was found to be considerably greater than 840 minutes.

Additional information

The photolysis of TCP in pure water was studied using a UV lamp generating light in the wave length spectrum from 185 to 360 nm. The rate of photolysis was determined in four experiments. Ten mL of test solution at a low concentration were exposed to UV light in quartz or pyrex tubes arranged around the lamp. The concentration of the substance was measured at set time intervals by gas chromatography. The half-life for photodegradation of TCP was found to be considerably greater than 840 minutes.