Pentapotassium bis(peroxymonosulphate) bis(sulphate)

Phototransformation in air

Link to relevant study record(s)

Reference

Endpoint:

phototransformation in air

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

key study

Study period:

2007-07-10

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: It is not a REACH requirement. The estimation is submitted for sake of completeness.

Qualifier:

no guideline followed

Principles of method if other than guideline:

model calculation according to the Atkinson calculation method

GLP compliance:

no

Estimation method (if used):

The photochemical and oxidative decompositions of Potassium peroxomonosulfate and Caro’s acid in air are calculated according to Atkinson.
The calculation is performed with the help of the programme AOPWIN, Atmospheric Oxidation Programme v1.92 for (© 2000 US Environmental Protection Agency).

Light source:

not specified

Details on light source:

not indicated

Details on test conditions:

not indicated

Reference substance:

not specified

Preliminary study:

not indicated

Test performance:

not indicated

Results with reference substance:

not indicated

OH radical reaction rate constant k_OH

The overall OH rate constant is estimated to be:

Potassium peroxomonosulfate kOH = 4.0000 × 10^-12 cm³ molecule-1 sec-1

Caro´acid (Peroxysulfuric acid) kOH =4.1400 × 10^-12 cm³ molecule-1 sec-1

 

Ozone reaction rate constant k_Ozone

As both substances contain no olefinic carbon-carbon double and acetylic triple bonds, Potassium peroxomonosulfate and Caro´s acid are not expect to react with ozone.

 

Atmospheric half-life using

k_OH

The tropospherical half life can be calculated using the following relation: t1/2 = ln2/kOH x [OH] with [OH] being the OH radicals concentration in the troposphere of 0.5 x 10⁶ molecule cm³ considering 24 hours irradiation per day.

The DT50 for Potassium peroxomonosulfate and Caro´s acid are estimated to be 4.011 days (24-hr day; corresponding to 96.264 hours) and 3.875 days (24-hr day; corresponding to 93.009 hours), respectively.

 

Atmospheric half-life using k_Ozone

No ozone reaction is estimated (Potassium peroxomonosulfate and Caro´s acid contain no olefinic carbon-carbon double and acetylic triple bonds)

Validity criteria fulfilled:

yes

Conclusions:

Potassium peroxomonosulfate and Caro’s acid degrade in the atmosphere with a DT50 value of 4.011 days (24-hr day; corresponding to 96.264 hours) and 3.875 days (24-hr day; corresponding to 93.009 hours), respectively. As both substances contain no olefinic carbon-carbon double and acetylic triple bonds, they are not expected to react with ozone.

Executive summary:

Materials and methods

The photochemical and oxidative decompositions of Potassium peroxomonosulfate and Caro´s acid in air are calculated according to Atkinson.

 

Results and discussion

Reaction rate constant

Potassium peroxomonosulfate kOH = 4.0000 × 10-12 cm3 molecule-1 sec-1

Caro´acid (Peroxysulfuric acid) kOH =4.1400 × 10-12 cm3 molecule-1 sec-1

 

Tropospherical half life

The DT50 for Potassium peroxomonosulfate and Caro´s acid are estimated to be 4.011 days (24-hr day; corresponding to 96.264 hours) and 3.875 days (24-hr day; corresponding to 93.009 hours), respectively.

Description of key information

The photochemical and oxidative decompositions of Potassium peroxomonosulfate and Caro´s acid in air are calculated according to Atkinson.

Potassium peroxomonosulfate kOH = 4.0000 × 10-12 cm3 molecule-1 sec-1

Caro´acid (Peroxysulfuric acid) kOH =4.1400 × 10-12 cm3 molecule-1 sec-1

 

Tropospherical half life

The DT50 for Potassium peroxomonosulfate and Caro´s acid are estimated to be 4.011 days (24-hr day; corresponding to 96.264 hours) and 3.875 days (24-hr day; corresponding to 93.009 hours), respectively.

Key value for chemical safety assessment

Half-life in air:

4.011 d

Degradation rate constant with OH radicals:

0 cm³ molecule-1 s-1