Emission of gaseous and volatile alkanes such as ethane, pentane, and hexane by plants has also been documented at low levels, though they are not generally considered to be a major component of biogenic air pollution.
ɪmˈɪʃən ʌv ɡˈæʃəs ænd vˈɑːlɐɾəl ˈælkeɪnz sˈʌtʃ ɐz ˈɛθeɪn, pˈɛnteɪn, ænd hˈɛkseɪn baɪ plˈænts hɐz ˈɔːlsoʊ bˌɪn dˈɑːkjuːməntᵻd æt lˈoʊ lˈɛvəlz, ðˌoʊ ðeɪ ɑːɹ nˌɑːt dʒˈɛnɚɹəli kənsˈɪdɚd təbi ɐ mˈeɪdʒɚ kəmpˈoʊnənt ʌv bˌaɪoʊdʒˈɛnɪk ˈɛɹ pəlˈuːʃən.