Irregardless is considered nonstandard because of the two negative elements ir- and -less. It was probably formed on the analogy of such words as irrespective, irrelevant, and irreparable. Those who use it, including on occasion educated speakers, may do so from a desire to add emphasis. Irregardless first appeared in the early 20th century and was perhaps popularized by its use in a comic radio program of the 1930s.
