Interlocks are required for alcohol related driving under the influences convictions. Utah law does not require the installation of an interlock devices when the underlying conviction does not involve alcohol. 
Utah Code 41-6a-518(2)(e) states:
This section does not apply to a person convicted of a violation of Section 41-6a-502 whose violation does not involve alcohol.
Utah Code 41-6a-518.2 states:
“(b)(iii) “Interlock restricted driver” does not include a person:
(A) whose current conviction described in Subsection (1)(b)(ii)(B) is a conviction under Section 41-6a-502 that does not involve alcohol or a conviction under Section 41-6a-517 and whose prior convictions described in Subsection (1)(b)(ii)(B) are all convictions under Section 41-6a-502 that did not involve alcohol or convictions under Section 41-6a-517;
(B) whose conviction described in Subsection (1)(b)(ii)(A) or (E) is a conviction under Section 41-6a-502 that does not involve alcohol and the convicting court notifies the Driver License Division at the time of sentencing that the conviction does not involve alcohol; or
(C) whose conviction described in Subsection (1)(b)(ii)(A), (B), or (D) is a conviction under Section 41-6a-502 that does not involve alcohol and the ignition interlock restriction is removed as described in Subsection (8). 
. . . .
(8)(a) An individual with an ignition interlock restriction may petition the division for removal of the restriction if the individual’s offense did not involve alcohol.”
