Here is some Info on the OMB.
6. How long can OIRA take to review a draft regulation?
Answer: The period for OIRA review is limited by the Executive Order to 90 days. There is no minimum period for review. Under the Executive Order, the review period may be extended by the head of the rulemaking agency, and the OMB Director may extend the review period on a one-time basis for no more than 30 days. The average review time for the 712 rules submitted to OMB during 2003 was 53 days.
Office of Information and Regulatory Affairs (OIRA) Q&A’s | The White House
Rules & Regulations