Reaction mass of calcium dihydroxide and calcium peroxide

Toxicity to terrestrial plants

Link to relevant study record(s)

Reference

Endpoint:

toxicity to terrestrial plants: short-term

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
Studies on terrestrial plants are not deemed necessary for both calcium peroxide and calcium hydroxide. On the one hand, calcium peroxide hydrolyses to calcium hydroxide and hydrogen peroxide when it comes into contact with moist. On the other hand, calcium hydroxide reacts with carbon dioxide in the environment to form calcium carbonate, which is one of the most abundant minerals in the earth's crust. Hydrogen peroxide is a short-lived substance in soil and ground water, because a rapid degradation will occur due to high concentration of catalytic material (transition metals, enzymes, easily oxidised/reduced organic substances and microbes) available. Furthermore, hydrogen peroxide also occurs naturally in the environment, for example in rainwater. In addition, hydrogen peroxide is continuously generated in physiological processes of the plants such as in the mitochondria. A complex system of antioxidant enzymes exists in plants that scavenges reactive oxygen species like hydrogen peroxide. It has also been suggested that hydrogen peroxide at lower doses acts as a signal molecule during plant growth and development. From this it is concluded that terrestrial plants can cope with the levels of exposure to hydrogen peroxide that are to be expected.

Description of key information

Data waiving (study scientifically not necessary): Studies on terrestrial plants are not deemed necessary for both calcium peroxide and calcium hydroxide. On the one hand, calcium peroxide hydrolyses to calcium hydroxide and hydrogen peroxide when it comes into contact with moist. On the other hand, calcium hydroxide reacts with carbon dioxide in the environment to form calcium carbonate, which is one of the most abundant minerals in the earth's crust. Hydrogen peroxide is a short-lived substance in soil and ground water, because a rapid degradation will occur due to high concentration of catalytic material (transition metals, enzymes, easily oxidised/reduced organic substances and microbes) available. Furthermore, hydrogen peroxide also occurs naturally in the environment, for example in rainwater. In addition, hydrogen peroxide is continuously generated in physiological processes of the plants such as in the mitochondria. A complex system of antioxidant enzymes exists in plants that scavenges reactive oxygen species like hydrogen peroxide. It has also been suggested that hydrogen peroxide at lower doses acts as a signal molecule during plant growth and development. From this it is concluded that terrestrial plants can cope with the levels of exposure to hydrogen peroxide that are to be expected.