Where does “pollution-free” come from?

pollution-free (English) comes from English pollution, from Middle English pollucioun, from Middle English polluten, from Middle French pollution, from Latin pollūtiō, from Latin -tiō, from Latin dissertātiō, from Latin dissertus — small stone, pebble; gravel, rubble.

Ancestry of “pollution-free”, step by step

pollution-free traces back through two separate lines of ancestry.

via English pollution

StepLanguageWordMeaning
1EnglishpollutionThe desecration of something holy or sacred;...
2Middle EnglishpolluciounThe ruining of the sacred; desecration
3Middle EnglishpollutenTo ruin the sacred; to desecrate
4Middle Frenchpollution
5Latinpollūtiōpollution, contamination, defilement
6Latin-tiōtion, -ation, -ing
7Latindissertātiō(spoken) dissertation, discourse, disquisition
8Latindissertusarranged, disposed; explained
9Latindissereresecond-person singular future passive indicative...
10Latindis-asunder, apart, in two; reversal, removal;...
11Latincalceusshoe
12Latincalxlimestone; chalk; the finish line
13Ancient Greekχάλιξsmall stone, pebble; gravel, rubble

via English Free

StepLanguageWordMeaning
1EnglishFreeUnconstrained
2EnglishfallerOne who falls; A fruit that falls from the tree,...
3English-erA person or thing that does an action indicated...
4Middle English-eragentive suffix; agent noun suffix
5Old French-erAlternative form of -ier, verbal suffix;...
6Latin-ārefirst conjugation
7Proto-Italic-āōForms primarily denominative verbs
8Proto-Indo-European-eh₂yétiCreates iterative/ frequentative/ intensive...
9Proto-Indo-European-yétiCreates intransitive, often deponent,...
10Proto-Indo-Europeanyé-
11Chichewaiyehe, she
Every word from Ancient Greek χάλιξEvery word from Latin -tiōEvery word from Latin dis-