Reaction products of sulphuric acid, rock phosphate and humic acids, potassium salts

Endpoint summary

Description of key information

Data to characterise the acute toxicity of the components of the submission substance is available from ammonium phosphate (oral LD50 in rats >2000 mg/kg bw, dermal LD50 in rats >5000 mg/kg bw, inhal. LC50, 4hvalue in rats >5 mg/L), calcium sulfate (oral LD50 in rats >1581 mg/kg bw, inhal. LC50, 4 h in rats >2.61mg/L) and from humic acids, potassium salts (oral and dermal LD50 in rats > 2000 mg/kg bw).

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

Sufficient: reliable studies for all components of the submission substance complex available

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

Sufficient: reliable studies for components phosphate and Ca sulfate of the submission substance complex available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

Sufficient: reliable studies for components phosphate and humic acid, potassium salt, of the submission substance complex available

Additional information

Read-across data is available from ammonium phosphate (oral, dermal, inhal.):

Acute oral toxicity of ammonium phosphate was determined according to OECD TG 425 and GLP. In total 3 female and 3 male sprague-dawley rats were administered 2000 mg/kg bw test substance by gavage and observed for 14 days. All animals survived, appeared active and healthy throughout the study period, gained weight and did not show gross abnormalities in necropsy and histopathology. Other findings were not reported. Therefore, the test substance did not seem to cause signs of toxicity in rats at the tested dose. It is concluded that the acute oral LD50 in rats is above 2000 mg/kg bw.

Assessment of acute inhalatory toxicity with diammonium hydrogenorthophosphate in the rat (OECD 403 and EU B.2): Diammonium hydrogenorthophosphate was administered as an aerosol by inhalation for 4 hours to one group of five male and five female Wistar rats. Animals were subjected to daily observations and determination of body weight on Days 1, 2, 4, 8 and 15. Macroscopic examination was performed after terminal sacrifice (day 15). The mean actual time-weighed concentration was 4.84 ± 0.28 mg/L. The nominal concentration was 442.92 mg/L. The generation efficiency (ratio of actual and nominal concentration) was 1.1%. The Mass Median Aerodynamic Diameter (MMAD) and geometric standard deviation (gsd) were determined twice. The MMAD was 6.0mm and 5.6mm respectively and the gsd was 1.8 in both cases. No mortality occurred and no clinical signs were noted during and after exposure. The body weight gain shown by the animals over the study period was considered to be normal. No abnormalities were found at macroscopic post mortem examination of the animals. Agglomeration of aerosol particles at this high concentration tested resulted in MMAD values to exceed the recommended range of 1 - 4 µm. Additional efforts to reduce the MMAD were unsuccessful and the MMAD remained significantly larger than 4 µm (i.e. use of a micronizing jet-mill and two cyclones, lowering the concentration down to 1 mg/L). Since the gsd of 1.8 determined during the actual exposure indicated that the aerosol was polydisperse and since approximately 20% of the particles were smaller than 4 µm, it can be assumed that test substance deposition in the lower respiratory tract occurred during the exposure. It was therefore considered that the outcome of this study is valid for the limit concentration of 5 mg/L.Since no mortality occurred at the limit concentration, no full study using lower concentrations was conducted. The inhalatory LC50, 4h value of diammonium hydrogenorthophosphate in Wistar rats was considered to exceed 5 mg/L under the conditions in this study.

Acute dermal toxicity of the ammonium phosphate was determined according to OECD TG 402 and GLP. Five male and 5 female sprague-dawley rats were applied 5000 mg/kg bw (as a paste of 85% test substance in water) occlusively for 24 hours and observed for 14 days. All animals survived, appeared active and healthy throughout the study period, gained weight and did not show gross abnormalities in necropsy and histopathology. No other signs of gross toxicity, adverse pharmacologic effects or abnormal behavior were observed. Therefore, the test substance did not seem to cause signs of toxicity in rats at the tested dose. It is concluded that the acute dermal LD50 in rats is above 5000 mg/kg bw.

Data is also available from the component calcium sulfate (oral, inhal.):

An acute oral toxicity study was performed with calcium sulfate dihydrate in rats which gave an LD 50 >2000 mg/kg. Based on this result the oral LD50 of calcium sulfate anydrous is >1581 mg/kg bw.

The acute inhalation median lethal concentration (4 hr LC50) of Calcium sulfate dihydrate, in the HsdHanTM : WIST strain rat, was greater than 3.26 mg/L, the equivalent LC50 value for the anhydrous form of this material is considered to be >2.61mg/L (added as the key value for CSA above).

The following data is available for humic acid potassium salt:

The tests of acute oral toxicity and acute dermal toxicity of humic acid potassium salts in rats were performed according to the following methods: B.1 tris: Acute Oral Toxicity - Acute Toxic Class Method, Directive 2004/73/EC, published in O.J. L152, 2004; B.3 Acute Toxicity (Dermal), Directive 92/69/EEC, published in OJ L 383A, 1992. Both: GLP study

Results of both acute toxicity studies (oral and dermal in rats): LD50 > 2000 mg/kg bw.

The acute toxicity of the components of the submission substance is very low for all relevant routes of administration.

Therefore, the submission substance is considered to have a very low acute oral, dermal and inhalative toxicity.

Justification for classification or non-classification

Based on the data described above, the submission substance does not have to be classified and has no obligatory labelling requirement for acute toxicity according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the United Nations (2007) and Regulation (EC) No 1272/2008 on classification, labelling and packaging of substances and mixtures.