2 typo fix edited Sep 3 '17 at 17:06 DrMoishe Pippik 16.6k1717 silver badges3636 bronze badges You might try horseradish as a catalyst, rather than yeast. Use the fresh root, not the prepared sauce, and test a few different plants - some are more effective than others. Cosmetic supply stores stock 6% (20 volume) $$\ce{H2O2}$$, but that concentration is more likely to cause skin irritation or bleach fabrics. The most effective catalyst for decomposing $$\ce{H2O2}$$] that I've used is potassium permanganate, $$\ce{KMnO4}$$, but it has a few liabilities: It's a strong oxidant and can start a fire when mixed with organic chemicals. It stains skin and fabric anything from pinkish-purple to black. The stain can be removed with sodium bisulfite, $$\ce{NaHSO3}$$, sold as an iron-stain remover. That can be a fun demonstration but is not suitable for young students to use. You might try horseradish as a catalyst, rather than yeast. Use the fresh root, not the prepared sauce, and test a few different plants - some are more effective than others. Cosmetic supply stores stock 6% (20 volume) $$\ce{H2O2}$$, but that concentration is more likely to cause skin irritation or bleach fabrics. The most effective catalyst for decomposing $$\ce{H2O2}$$] that I've used is potassium permanganate, $$\ce{KMnO4}$$, but it has a few liabilities: It's a strong oxidant and can start a fire when mixed with organic chemicals. It stains skin and fabric anything from pinkish-purple to black. The stain can be removed with sodium bisulfite, $$\ce{NaHSO3}$$, sold as an iron-stain remover. That can be a fun demonstration but is not suitable for young students to use. You might try horseradish as a catalyst, rather than yeast. Use the fresh root, not the prepared sauce, and test a few different plants - some are more effective than others. Cosmetic supply stores stock 6% (20 volume) $$\ce{H2O2}$$, but that concentration is more likely to cause skin irritation or bleach fabrics. The most effective catalyst for decomposing $$\ce{H2O2}$$ that I've used is potassium permanganate, $$\ce{KMnO4}$$, but it has a few liabilities: It's a strong oxidant and can start a fire when mixed with organic chemicals. It stains skin and fabric anything from pinkish-purple to black. The stain can be removed with sodium bisulfite, $$\ce{NaHSO3}$$, sold as an iron-stain remover. That can be a fun demonstration but is not suitable for young students to use. 1 answered Sep 3 '17 at 5:39 DrMoishe Pippik 16.6k1717 silver badges3636 bronze badges You might try horseradish as a catalyst, rather than yeast. Use the fresh root, not the prepared sauce, and test a few different plants - some are more effective than others. Cosmetic supply stores stock 6% (20 volume) $$\ce{H2O2}$$, but that concentration is more likely to cause skin irritation or bleach fabrics. The most effective catalyst for decomposing $$\ce{H2O2}$$] that I've used is potassium permanganate, $$\ce{KMnO4}$$, but it has a few liabilities: It's a strong oxidant and can start a fire when mixed with organic chemicals. It stains skin and fabric anything from pinkish-purple to black. The stain can be removed with sodium bisulfite, $$\ce{NaHSO3}$$, sold as an iron-stain remover. That can be a fun demonstration but is not suitable for young students to use.