| HYDROGENPEROXIDE | Chemical compound, with the formula H2O2, used as an oxidiser, bleaching agent and antiseptic (8,8) |
| PEROXIDED | Treated with H2O2 in order to bleach it (hair) (9) |
| MALEICACID | Chemical compound with the formula HOOCCH:CHCOOH, used in making synthetic resins (6,4) |
| LYE | Chemical compound with the formula NaOH |
| OXALICACID | Chemical compound with the formula H2C2O4 |
| ISOMER | Chemical compound with the same formula as another |
| SILICA | White colourless chemical compound with the chemical formula SiO2 (6) |
| HYDROGENCYANIDE | Organic compound with the formula HCN, also known as prussic acid (8,7) |
| ETHANE | Natural-gas compound with the formula C2H6 |
| CHLORINE | Halogen used to sterilize water and wastes, and it's used as a bleaching agent for paper or textiles. During World War I, it was an important component of phosgene gas. |
| CLASSIFIEDAWARDS | Best Secret Agent and others? |
| SILVERIODIDE | Light-sensitive compound with the chemical formula AgI, used in pre-digital photography (6,6) |
| NITROUS | Chemical compound, commonly known as laughing gas, with the formula N2O; ... oxide |
| TEATREEOIL | Liquid from an Australian plant with antibacterial and antiseptic properties (3,4,3) |
| OZONE | What is the name of the pungent gas with the formula O3? (5) |
| METHANE | Compound with the chemical formula CH4 (7) |
| STEROL | Chemical compound in some plants with the formula C17H28O (6) |
| ODORANT | Chemical compound with an aroma |
| ETHER | An organic compound with the group -O- in its molecules |
| PEROXIDE | Ten, in the time of one lesson, start to examine a bleaching agent (8) |
