Phosphorus

Endpoint summary

Additional information

TOXICITY TO FISH

Short-term toxicity to fish

Since red phosphorus is an amorphous polymeric form of elemental phosphorus, it is insoluble in water or organic solvents. However, there is a slow (probably kinetically controlled) decomposition of red phosphorus in water: disproportioning and oxidizing reactions in aqueous solution produce mainly phosphorus acids(H₃P0₄, H₃P0₃₎H₃P0₂) and traces of unknown phosphorus compounds in small mg per liter concen-trations.

Therefore red phosphorus was tested in 3 Guideline tests in zebra fish (Danio rerio) for 96 hours in a static system.

The contents were stirred for 24 hours or 7 days with a magnetic stirrer in order to test the toxicity of the water soluble decomposition products. The reaction period of 7 days is recommended by the European Chemicals Bureau for substances which decompose or react very slowly in water. To remove undissolved particles the dispersion was filtered through a cellulose filter and/or a membrane filter. The resulting solution was visually clear. No particulate matter was observed.

In the acute toxicity studies of red phosphorus the following EC/LC50 values were determined:

 

	LC50/EC50-values nominal concentration (mg/L)				corresponding mean measured concentration of total phosphorus (mg/L)
	24 hours	48 hours	72 hours	96hours	24 hours	48 hours	72 hours	96hours
LC50	> 50	33.2	33.2	33.2	> 1.41	0.95	0.95	0.95
EC50	>100	>100	>100	>100	>0.73	>0.73	>0.73	>0.73
EC50	>100	>100	>100	>100	>0.73	>0.73	>0.73	>0.73

 

Under the conditions of these tests the LC50 of Phosphorus Red SF after 96 hours was 33.2 mg/L (based on nominal concentration). This value corresponds to a concentration of total phosphorus in solution of 0.95 mg/L, calculated from analytical determinations.

Long-term toxicity to fish

Red phosphorus is physically insoluble in water due to its polymeric nature. Therefore the aquatic environment is not the target compartment and a direct or indirect exposure of the aquatic compartment is unlikely.

Short-term toxicity tests are available according AnnexVII, Column 1, 9.1.1 and 9.1.2 and according Annex VIII, Column 1, 9.1.3 and 9.1.4. The chemical safety assessment according Annex I does not indicate the need to investigate further the effects on aquatic organisms. Based on this fact long-term toxicity tests are not warranted.

The statement given above fulfills the requirement for waiving as given in 1907/2006/EC Annex IX Column 2, 9.1: "The chemical safety assessment according Annex I does not indicates the need to investigate further the effects on aquatic organisms".

TOXICITY TO DAPHNIA

Short-term toxicity to aquatic invertebrates

Phosphorus red was tested in 2 Guideline studies in Daphnia magna (water flea) for 48 hours in a static system.

Since red phosphorus is an amorphous polymeric form of elemental phosphorus, it is insoluble in water or organic solvents. However, there is a slow (probably kinetically controlled) decomposition of red phosphorus in water: disproportioning and oxidizing reactions in aqueous solution produce mainly phosphorus acids (H₃P0₄, H₃P0₃, H₃P0₂) and traces of unknown phosphorus compounds in small mg per liter concentrations.

 

For each individual test concentration the test substance was weighed into a beaker and mixed with water for dilution. The mixture was transferred quantitatively into a 5 liter glass bottle. The bottles were filled up to their maximum and were closed. The contents were then stirred for 24 hours or 7 days with a magnetic stirrer. The reaction period of 7 days is recommended by the European Chemicals Bureau for substances which decompose or react very slowly in water. To remove undissolved particles the dispersion was filtered through a cellulose filter and/or a membrane filter. The resulting solution was visually clear. No particulate matter was observed.

In the 48-hour acute toxicity studie of red phosphorus the following EC50 immobility values were determined:

	EC-values nominal concentration (mg/L)		corresponding mean measured concentration of total phosphorus (mg/L)
	24 hours	48 hours	24 hours	48 hours
EC50	36.7	10.5	1.57	0.63
EC50	130.6	35.6	1.18	0.63

Under the conditions of these tests theEC₅₀of red phosphosrus after48hours was10.5 mg/L.This value corresponds toaconcentration of total phosphorus in solution of 0.63mg/L, calculated from analytical determinations.

Long-term toxicity to aquatic invertebrates

Red phosphorus is physically insoluble in water due to its polymeric nature. Therefore the aquatic environment is not the target compartment and a direct or indirect exposure of the aquatic compartment is unlikely.

Short-term toxicity tests are available according AnnexVII, Column 1, 9.1.1 and 9.1.2 and according Annex VIII, Column 1, 9.1.3 and 9.1.4. The chemical safety assessment according Annex I does not indicate the need to investigate further the effects on aquatic organisms. Based on this fact long-term toxicity tests are not warranted.

The statement given above fulfills the requirement for waiving as given in 1907/2006/EC Annex IX Column 2, 9.1: "The chemical safety assessment according Annex I does not indicates the need to investigate further the effects on aquatic organisms".

TOXICITY TO ALGAE

The purpose of the two studis was to determine the effects of red phosphorus on the growth of a unicellular green algae species. Exponentially-growing cultures of Desmodesmus subspicatus were exposed to various concentrations of the test substance over several generations under defined conditions. The test solutions were incubated for a period of 72 hours.

Since PHOSPHORUS RED is an amorphous polymeric form of elemental phosphorus, it is insoluble in water or organic solvents. However, there is a slow (probably kinetically controlled) decomposition of red phosphorus in water: disproportioning and oxidizing reactions in aqueous solution produce mainly phosphorus acids (H3P04, H3P03, H3P02) and traces of unknown phosphorus compounds in small mg per liter concentrations.

In the key study for each individual test concentration the test substance was weighed into a beaker and mixed with water for dilution. The mixture was transferred quantitatively into a 5 liter glass bottle. The bottles were filled up to their maximum and were closed. The contents were then stirred for 7 days with a magnetic stirrer. The reaction period of 7 days is recommended by the European Chemicals Bureau for substances which decompose or react very slowly in water. To remove undissolved particles the dispersion was filtered through a membrane filter of 0.2 µm pore size. The resulting solution was visually clear. No particulate matter was observed.

On the basis of the experimental data a nominal EC50 of 18.3 mg/L based on growth rate was determined. The details of the nominal effect concentrations are summarized in the following table:

	Biomass(mg/L)	Growth rate(mg/L)
EC50(0-72h)	9.5	18.3	Aventis 2001
EC10(0-72h)	4.9	6.6
NOEC(0-72h)	n.c.	5.0
EC50(0-72h)	56.5	246.0*	Ibacon 2000
EC10(0-72h)	16.7	43.5
NOEC(0-72h)	12.5	12.5

 

TOXICITY TO AQUATIC MICROORGANISM

The EC50 of red phosphorous in contact with bacteria sludge of a communal sewage treatment plant is above the nominal contentration of the test

EC50: > 1000 mg/1