Dipotassium oxide

Bioaccumulation: terrestrial

Link to relevant study record(s)

Reference

Endpoint:

bioaccumulation: terrestrial

Data waiving:

other justification

Justification for data waiving:

other:

Description of key information

  This substance has a limited potential to bioaccumulate (based on log Kow used : -1.38, Log Kow (experimental):  -1.38 , and predicted bioconcentration factors, log BCF = 0.5 (EPIWIN/BCF Program).
According to “ANNEX IX- STANDARD INFORMATION REQUIREMENTS FOR SUBSTANCES MANUFACTURED OR IMPORTED IN QUANTITIES OF 100 TONNES OR MORE , a bioaccumulation study need not be conducted if:
— the substance has a low potential for bioaccumulation (for instance a log Kow ≤ 3) and/or a low potential to cross biological membranes, or
— direct and indirect exposure of the aquatic compartment is unlikely.
The estimated Log BCF of Potassium oxide is 0.5 (BCF = 3.162 L/kg wet-wt)

Key value for chemical safety assessment

BCF (terrestrial species):

3.16 L/kg ww

Additional information

BCFBAF Program (v3.01) Results:

==============================

SMILES : KOK

CHEM  : Potash (potassium oxide)

MOL FOR: O1

MOL WT : 94.20

--------------------------------- BCFBAF v3.01 --------------------------------

Summary Results:

 Log BCF (regression-based estimate): 0.50 (BCF = 3.16 L/kg wet-wt)

 Biotransformation Half-Life (days) : 0.00627 (normalized to 10 g fish)

 Log BAF (Arnot-Gobas upper trophic): -0.05 (BAF = 0.894 L/kg wet-wt)

 

Log Kow (experimental): -1.38

Log Kow used by BCF estimates: -1.38

 

Equation Used to Make BCF estimate:

  Log BCF = 0.50

 

     Correction(s):                   Value

      Correction Factors Not Used for Log Kow < 1

 

  Estimated Log BCF = 0.500 (BCF = 3.162 L/kg wet-wt)

 

===========================================================

Whole Body Primary Biotransformation Rate Estimate for Fish:

===========================================================

------+-----+--------------------------------------------+---------+---------

 TYPE | NUM | LOG BIOTRANSFORMATION FRAGMENT DESCRIPTION | COEFF | VALUE 

------+-----+--------------------------------------------+---------+---------

 L Kow| * | Log Kow = -1.38 (experimental  )       | 0.3073 | -0.4241

 MolWt| * | Molecular Weight Parameter               |        | -0.2415

 Const| * | Equation Constant                        |        | -1.5371

============+============================================+=========+=========

  RESULT  |       LOG Bio Half-Life (days)           |        | -2.2027

  RESULT  |           Bio Half-Life (days)           |        | 0.00627

  NOTE    | Bio Half-Life Normalized to 10 g fish at 15 deg C  |

============+============================================+=========+=========

 

Biotransformation Rate Constant:

 kM (Rate Constant): 110.6 /day (10 gram fish)

 kM (Rate Constant): 62.17 /day (100 gram fish)

 kM (Rate Constant): 34.96 /day (1 kg fish)

 kM (Rate Constant): 19.66 /day (10 kg fish)

 

Arnot-Gobas BCF & BAF Methods (including biotransformation rate estimates):

  Estimated Log BCF (upper trophic) = -0.049 (BCF = 0.8939 L/kg wet-wt)

  Estimated Log BAF (upper trophic) = -0.049 (BAF = 0.8939 L/kg wet-wt)

  Estimated Log BCF (mid trophic)  = -0.030 (BCF = 0.9325 L/kg wet-wt)

  Estimated Log BAF (mid trophic)  = -0.030 (BAF = 0.9325 L/kg wet-wt)

  Estimated Log BCF (lower trophic) = -0.026 (BCF = 0.9412 L/kg wet-wt)

  Estimated Log BAF (lower trophic) = -0.026 (BAF = 0.9412 L/kg wet-wt)

 

Arnot-Gobas BCF & BAF Methods (assuming a biotransformation rate of zero):

  Estimated Log BCF (upper trophic) = -0.047 (BCF = 0.8975 L/kg wet-wt)

  Estimated Log BAF (upper trophic) = -0.047 (BAF = 0.8975 L/kg wet-wt)