Sodium peroxide and potassium superoxide react with carbon dioxide to form the alkali metal carbonate and oxygen gas, which allows them to be used in submarine air purifiers; the presence of water vapour, naturally present in breath, makes the removal of carbon dioxide by potassium superoxide even more efficient.
sˈoʊdiəm pəɹˈɑːksaɪd ænd pətˈæsiəm sˌuːpɚɹˈɑːksaɪd ɹɪˈækt wɪð kˈɑːɹbən daɪˈɑːksaɪd tə fˈɔːɹm ðɪ ˈælkəlˌaɪ mˈɛɾəl kˈɑːɹbənˌeɪt ænd ˈɑːksɪdʒən ɡˈæs, wˌɪtʃ ɐlˈaʊz ðˌɛm təbi jˈuːzd ɪn sˈʌbmɚɹˌiːn ˈɛɹ pjˈʊɹɹɪfˌaɪɚz; ðə pɹˈɛzəns ʌv wˈɔːɾɚ vˈeɪpɚ, nˈætʃɚɹəli pɹˈɛzənt ɪn bɹˈɛθ, mˌeɪks ðə ɹᵻmˈuːvəl ʌv kˈɑːɹbən daɪˈɑːksaɪd baɪ pətˈæsiəm sˌuːpɚɹˈɑːksaɪd ˈiːvən mˈoːɹ ɪfˈɪʃənt.