[iminobis(ethyleneiminomethylene)]bis(phosphonic) acid, N,N-bis(phosphonomethyl) derivative, sodium salt

Biodegradation in soil

Administrative data

Endpoint:

biodegradation in soil

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study well documented, meets generally accepted scientific principles, acceptable for assessment. The test substance in this study is the penta-phosphonate form and is one of the components in the substance to be registered.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1978

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

20-unit biodegradation test using 14CO2 evolution to determine degree of biodegradation. Sterilised soils used as a control.

GLP compliance:

no

Test type:

laboratory

Test material

Test material information

Constituent 1

Reference substance name:

[[(phosphonomethyl)imino]bis[ethane-2,1-diylnitrilobis(methylene)]]tetrakisphosphonic acid

EC Number:

239-931-4

EC Name:

[[(phosphonomethyl)imino]bis[ethane-2,1-diylnitrilobis(methylene)]]tetrakisphosphonic acid

Cas Number:

15827-60-8

IUPAC Name:

[(bis{2-[bis(phosphonomethyl)amino]ethyl}amino)methyl]phosphonic acid

Radiolabelling:

yes

Study design

Oxygen conditions:

aerobic

Soil classification:

not specified

Soil properties

Soil properties 1

Soil no.:

#1

Soil type:

other: Meramec river bank

% Org. C:

0.7

pH:

7.7

Soil properties 2

Soil no.:

#2

Soil type:

other: St. Charles Ray Silt Loam

% Org. C:

0.56

pH:

7.05

Parameter followed for biodegradation estimation:

radiochem. meas.

Results and discussion

% Degradation

% Degr.:

64

Sampling time:

148 d

Half-life / dissipation time of parent compound

Type:

(pseudo-)first order (= half-life)

Transformation products:

not measured

Evaporation of parent compound:

not measured

Volatile metabolites:

no

Residues:

not measured

Any other information on results incl. tables

Cumulative C-14 Evolved (% theory)
Day of exposure:  Silt loam (microbial), Silt loam
(sterile); River bank (microbial), River bank (sterile)

LAS
Day   2:   0.03, 0;     0.05, 0.02
Day   6:   0.14, 0.02;  0.20, 0.05
Day  12:   2.20, 0.05;  1.90, 0.08
Day  16:   4.53, 0.05;  4.51, 0.08
Day  21:   7.69, 0.05;  9.20, 0.08
Day  28:  11.46, 0.07; 15.79, 0.08
Day  35:  15.68, 0.07; 24.02, 0.08
Day  43:  20.49, 0.07; 33.92, 0.08
Day  58:  29.44, 0.07; 51.04, 0.08
Day  72:  36.34, 0.08; 61.98, 0.10
Day  86:  41.92, 0.08; 68.46, 0.10
Day 100:  46.59, 0.08; 72.36, 0.10
Day 114:  50.41, 0.08; 74.86, 0.10
Day 128:  53.60, 0.08; 76.80, 0.10
Day 148:  56.97, 0.10; 79.12, 0.15

Test substance
Day   2:  16.60, 12.79; 15.89, 1.81
Day   6:  25.11, 15.46; 21.62, 2.32
Day  12:  30.38, 17.00; 26.24, 2.60
Day  16:  33.22, 17.55; 29.19, 2.72
Day  21:  36.00, 17.97; 32.93, 2.82
Day  28:  39.03, 18.23; 36.86, 2.94
Day  35:  41.75, 18.45; 40.65, 3.01
Day  43:  44.37, 18.61; 44.18, 3.08
Day  58:  48.64, 18.83; 49.50, 3.20
Day  72:  51.86, 18.96; 53.14, 3.30
Day  86:  54.60, 19.04; 56.01, 3.37
Day 100:  56.96, 19.10; 58.36, 3.45
Day 114:  58.88, 19.14; 60.30, 3.51
Day 128:  60.50, 19.17; 61.92, 3.58
Day 148:  62.55, 19.23; 63.97, 3.67

The data suggest that no induction period is required before
degradation occurs.

The high C-14 evolution observed in the sterilised St.
Charles ray-silt loam soil samples is likely to be due to
the time required for the sodium azide sterilant to be
distributed throughout the soil.

Applicant's summary and conclusion

Conclusions:

There are degradation modes operative in the environment
which could prevent long-term persistence.