Ammonium 2-amino-4-(hydroxymethylphosphinyl)butyrate

Bioaccumulation: aquatic / sediment

Description of key information

Glufosinate-ammonium has no potential to bioaccumulate in fish. The BCF was determined to be < 1 (Fischer & Schwalbe-Fehl, 1985; M-112648-01-1).

Additional information

The potential for bioaccumulation of glufosinate-ammonium in fish was investigated by Fischer & Schwalbe-Fehl (1985; M-112648-01-1) in accordance with EPA Pesticide Assessment Guidelines, Subdivision N: Environmental fate, §165-4 (October 1982). Lepomis macrochirus were exposed to the test substance 3,4 -¹⁴C-glufosinate-ammonium (AE F039866, purity 98%) in a continuous flow through system at a nominal concentration of 0.1 mg/L (mean measured concentration: 0.094 ± 0.010 mg/L) for 28 days followed by a 14 day depuration period. In total, 100 fish (age 5 months, 51 mm length) were exposed. The mean test temperature was 22 °C, pH 8.2. The radioactivity in fish and water was measured on day 0, 1, 3, 7, 14, 21 and 28 of the exposure period and on days 1, 3, 7, 10 and 14 of the depuration. Measurements were made in whole fish, and edible/non-edible parts. On days 3 and 21 fish were taken for metabolite identification.

The measured radioactivity in fish on day 28 of the uptake phase were 0.018 µg glufosinate-ammonium equivalents/g whole fish (fresh weight), 0.012 µg/g in edible tissues, and 0.034 µg/g in non-edible parts of the fish. At the end of the depuration phase, radioactivity concentrations were either below the limit of detection (0.004 µg/g) for edible tissues or insignificantly higher (0.005 µg/g for whole fish and 0.006 µg/g for non-edible tissues, respectively).. From the results it can be concluded that BCF for fish is <1. Hence, no bioaccumulation of glufosinate-ammonium is expected.

During biodegradation simulation studies in water, water-sediment and soil systems several metabolites with an amount > 0.1 % were determined. For assessment of their potential bioaccumulation potential their logKow was calculated using the KOWWIN v1.68 module of EPI Suite v4.11.

All calculated logKow values were clearly below the threshold value of 4.5 as stated in ECHA Guidance on Information Requirements and Chemical Safety Assessment Chapter R.7c. Therefore an bioaccumulative potential of metabolites of glufosinate-ammonium under environmental conditions can be excluded.

Compound information	Log Kow	Comments
MPA CP(=O)(CC(=O)O)O	-1.10	AE F064619 Soil (aerobic) at 28% TAR
MPP CP(=O)(CCC(=O)O)O	-1.41	AE F061517 Soil (aerobic) at 62% TAR Water/Sediment (aerobic) at 59%TAR
PPO CP(=O)(CCC(=O)C(=O)O)O	-2.74	AE F065594 Soil (aerobic) at 25% TAR Mineralization in surface water (aerobic) at 8.0% TAR
Glufosinate Free Acid CP(=O)(CCC(C(=O)O)N)O	-4.49	AE F035956 Free acid form of active substance. Used as reference item in analysis but not used as test item.
AE F130948 CP(=O)(O)O	-1.00	AE F130948 Soil (aerobic) at 58% TAR
Glufosinate hydrochloride AE F035125 CP(=O)(CCC(C(=O)O)[NH3+])O.[Cl-]	-4.49	The log Kow for glufosinate free acid is used here. Log Kow is not predcited for a salt, only the organic part of the salt. The salt would not exist in solution. AE F035125 Not used as test item. Used for preparation of radio-isotope.
Glufosinate ammoniun AE F039866 CP(=O)(CCC(C(=O)[O-])N)O.[NH4+]	-4.49	The log Kow for glufosinate free acid is used here. Log Kow is not predcited for a salt, only the organic part of the salt. The salt would not exist in solution. AE F039866 Active substance
AE F078091 [H]P(=O)(C)O	-1.17	AE F078091 Soil (aerobic) at <2.0% TAR Water/Sediment (aerobic) at 47%TAR
AE F130947 CP(=O)(C(=O)O)O	-1.86	AE F130947 Water/Sediment (aerobic) at 23% TAR
NAG CC(=O)N[C@@H](CCP(=O)(C)[O-])C(=O)[O-].[Na+].[Na+]	-2.10	Log Kow is not predcited for a salt, only the organic part of the salt. The salt would not exist in solution. AE F099730 Mineralization in surface water (aerobic) at 26% TAR Water/Sediment (aerobic) at 14%TAR
AE 0015081 CP(=O)(/C=C/C(=O)O)O	-1.62	AE 0015081 Water/Sediment (aerobic) at <5.0% TAR