for all intensive purposes

adverb

a) Misconstruction of “for all intents and purposes”.<ref name="ET2">“[ for all intensive purposes]” \@ everything2 by “jadams2484” (2001)</ref><ref name="CEiE">“[ for all intensive purposes]” in Common Errors in English, by Paul Brians</ref><ref name="ActGram">ActionGrammar by Joanne Feierman (found in the chapter “Mistakes Your Boss Minds the Most”, in the section “Twenty More Language Pet Peeves”, on page 26, and also listed on page 212)</ref><ref name="TDoDE">The Dictionary of Disagreeable English by Fiske, page 136</ref><ref name="AUE-FAQ">“[ to all intents and purposes]” Mark Israel’s AUE FAQ (September 1997)</ref><ref name="GBW">The Broadview Guide to Writing by Doug Babington & Don LePan, page 241 (3 Ed., 2005)</ref><ref name="HoW">The How of WOW: A Guide to Giving a Speech That Will Positively Blow ‛Em Away by Tony Carlson, page 159 (2005)</ref><ref name="WR!">Write Right!: A Desktop Digest of Punctuation, Grammar, and Style by Jan Venolia, page 112 (2001)</ref><ref name="AngEng">Anguished English: An Anthology of Accidental Assaults Upon the English Language by Richard Lederer, page 178 (2006)</ref><ref name="TED">“[ intensive purposes]” in The Eggcorn Database (version 0·5), by Chris Waigl</ref>

This fire-resistant material is a perfect electrical insulator for all intensive purposes.

b) For all highly demanding purposes.<ref name="ET2"/>

See Also: for all intended purposes, for all intense and purposes, for all intense purposes, for all intrinsic purposes