Registration Dossier

Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
PNEC aqua (freshwater)
PNEC value:
0.1 mg/L
Assessment factor:
1 000
Extrapolation method:
assessment factor
PNEC freshwater (intermittent releases):
0.1 mg/L

Marine water

Hazard assessment conclusion:
PNEC aqua (marine water)
PNEC value:
0.1 mg/L
Assessment factor:
1 000
Extrapolation method:
assessment factor

STP

Hazard assessment conclusion:
PNEC STP
PNEC value:
1 mg/L
Assessment factor:
1 000
Extrapolation method:
assessment factor

Sediment (freshwater)

Hazard assessment conclusion:
no data available: testing technically not feasible

Sediment (marine water)

Hazard assessment conclusion:
no data available: testing technically not feasible

Hazard for air

Air

Hazard assessment conclusion:
no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:
no data available: testing technically not feasible

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no data available: testing technically not feasible

Additional information

Aquatic: This substance is an inorganic synthetic version of Hectorite clay, which commonly occurs in nature and is in the same family of clays as bentonite.

The material is inorganic and by virtue of this it is non-biodegradable, retaining its clay structure in the environment. At normal water course pH’s this material is stable and insoluble. It does not dissolve in water but disperses to form a clear sol and in the pH range 4 – 9 does not hydrolyse.

The majority of the applications for which this substance is used will not result in the material being released to water courses directly. Personal care product applications such as toothpaste, shower gels, shampoos, cosmetics etc and also household product applications such as dishwasher detergent and toilet cleaners will result in very low concentrations of this substance (<100 mg/l) being released into the domestic sewage system and finding its way into water treatment works. This substance has a high molecular weight, when hydrated forms a sol (or a gel at higher concentrations) and studies within the manufacturing effluent treatment facility suggest that the material sediments and is retained in the solid waste rather than going forward in the flume / purified water released to the river.

If low concentrations do get through the water treatment process and enter the water course, the fact that the material does not biodegrade, is not soluble, does not hydrolyse and is of a high molecular weight suggest that transfer across biological membranes is unlikely. In addition, short term aquatic toxicity tests carried out on fish and daphnia show this substance is not toxic to marine life. On this basis the need for long term aquatic testing is waived.

Soil: This substance is an inorganic synthetic version of Hectorite clay, which occurs in nature and is part of the soil mineralogy in parts of the world. Hectorite clay is a smectite clay and is in the same family of clays as bentonite, which is common in nature. Clays are not known to be detrimental to animals, birds, insects, microbes or plants.

The material is non-biodegradable because of it is inorganic, retaining its clay structure in the environment. At normal soil environmental pH’s this material is stable. It does not dissolve in water but disperses to form a clear sol and in the pH range 4 – 9 does not hydrolyse.

The majority of the applications for which this substance is used will not result in the material being released to the soil. However, Laponite®, which is a commercial product of this substance, has applications in agriculture and horticulture as an inert ingredient in formulations applied to growing crops or to raw agricultural crops after harvest. It is used as a medium for seed germination and a rooting medium and also as a non-toxic antistatic and barrier coating for seeds.

Conclusion on classification

Not classified as hazardous. Effect on algal growth seen to be due to water chemistry effects and not directly to toxicity of the substance