Rules not subject to congressional review may still be at risk. The most radical shift has perhaps come at the Federal Communications Commission, which voted on Wednesday to halt new government rules related to data security from taking effect this week, after objections were raised by companies including Comcast, Verizon and AT&T.

Ajit Pai, a Republican whom Mr. Trump recently named as the F.C.C. chairman, has also made clear that he intends to push to roll back or abandon several other major rules, including the landmark net neutrality regulation intended to ensure equal access to content on the internet, as well as efforts to keep prison phone rates down and a proposal to break open the cable box market.

The efforts have been praised by telecommunications giants, like Comcast, but condemned by consumer advocates.

The administration started its campaign against regulation on the afternoon of Inauguration Day, with a memo from Reince Priebus, Mr. Trump’s chief of staff, instructing agencies to halt work on new regulations and to delay putting completed regulations into effect.

So far, the effective dates of at least 75 rules have been delayed as a result of this order, based on an analysis of the Federal Register. That includes a measure intended to prevent potentially toxic formaldehyde exposure in homes caused by certain furniture products — an effort that has been underway since victims of Hurricane Katrina in 2005 were moved into contaminated government-issued trailers.

Such delays are not uncommon with new presidents — both George W. Bush and Mr. Obama did the same, to differing degrees. And certain measures are still going into effect as the Trump administration gets underway, including one that prohibits smoking in public housing nationwide as of Feb. 3.

Still, the general Trump administration freeze has drawn broad opposition, some of it surprising. The Department of Agriculture has delayed a rule that would make it easier for chicken farmers to sue chicken processors. Business groups, including the National Federation of Independent Business, want to kill the rule.