As President Donald Trump reaches his 100th day in the White House on April 29, he will have worked with Congress to rescind more regulations using the Congressional Review Act than any other president.

“We’re excited about what we’re doing so far. We’ve done more than that’s ever been done in the history of Congress with the CRA,” Rep. Doug Collins, R-Ga., told The Daily Signal in an interview, referring to the law called the Congressional Review Act.

The Congressional Review Act, the tool Trump and lawmakers are using to undo these regulations, allows Congress to repeal executive branch regulations in a certain window of time.

“Under the Congressional Review Act, Congress is given 60 legislative days to disapprove a rule and receive the president’s signature, after which the rule goes into effect,” Paul Larkin, a senior legal research fellow at The Heritage Foundation, wrote in a February report. The 60 days begins after Congress is notified that a rule has been finalized.

Once the House and Senate pass a joint resolution disapproving of a particular regulation, the president signs the measure.

Passed in 1996 in concert with the Small Business Regulatory Enforcement Fairness Act and then-Speaker Newt Gingrich’s Contract with America reform agenda, the Congressional Review Act is what the Congressional Research Service calls “an oversight tool that Congress may use to overturn a rule issued by a federal agency.”

The law also prevents agencies from creating similar rules with similar language.

Until this year, the law had been used successfully only once—in 2001, when Congress and President George W. Bush rescinded a regulation regarding workplace injuries promulgated by the Occupational Safety and Health Administration during the Clinton administration.

Here’s a look at 13 regulatory rollbacks Congress has passed and Trump has signed:

1. Regulations governing the coal mining industry (H.J. Res 41).

Mandated by President Barack Obama and finalized in 2016, these regulations “threatened to put domestic extraction companies and their employees at an unfair disadvantage,” White House press secretary Sean Spicer said.

The resolution, signed by Trump in February, repealed the rule and “could save American businesses as much as $600 million annually,” Spicer said.

2. Regulations defining streams in the coal industry (H.J. Res 38).

“Complying with the regulation would have put an unsustainable financial burden on small mines,” Spicer said.

The so-called Stream Protection Rule included “vague definitions of what classifies as a stream,” Nick Loris, a fellow in energy and environmental policy at The Heritage Foundation, told The Daily Signal in an email, and undoing it does away with ambiguities:

For many regulations promulgated by the Obama administration, they fundamentally disregarded the nature of the federal-state relationship when it comes to energy production and environmental protection. The Stream Protection Rule … removed flexibility from mining steps and simply ignored that states have regulations in place to protect water quality. State and local environmental agencies’ specific knowledge of their region enables them to tailor regulations to promote economic activity while protecting the habitat and environment.

'Trump signs bill undoing Obama coal mining rule' https://t.co/yMfT5r5RGh — Donald J. Trump (@realDonaldTrump) February 16, 2017

3. Regulations restricting firearms for disabled citizens (H.J. Res 40).

This rule, finalized during Obama’s last weeks in office, sought to “prevent some Americans with disabilities from purchasing or possessing firearms based on their decision to seek Social Security benefits,” Spicer said.

The repeal protects the Second Amendment rights of the disabled, Senate Judiciary Chairman Sen. Chuck Grassley, R-Iowa, said.

“Those rights will no longer be able to be revoked without a hearing and without due process. It will take more than the personal opinion of a bureaucrat,” Grassley said on the Senate floor.

But Rep. Mike Thompson, D-Calif., said the regulation didn’t cover “just people having a bad day,” adding:

These are not people simply suffering from depression or anxiety. These are people with a severe mental illness who can’t hold any kind of job or make any decisions about their affairs. So the law says very clearly they shouldn’t have a firearm.

4. A rule governing the government contracting process (H.J. Res. 37).

Undoing the regulation will cut costs to businesses and free federal contractors from “unnecessary and burdensome processes that would result in delays, and decreased competition for federal government contracts,” Spicer said.

5. A rule covering public lands (H.J. Res. 44).

The rule gave the federal government too much power “to administer public lands,” in the words of the official website of House Majority Leader Kevin McCarthy, R-Calif.

Sen. Mike Lee, R-Utah, told The Daily Signal in an interview that the Bureau of Land Management’s rule restricted the control that states and their citizens had, especially in the West.

“The Obama administration wanted to shift land policy from local governments with specific expertise to the federal government, basically shifting even more of the land management policy away from those affected by it,” Lee said.

“Repealing this harmful rule will go a long way toward empowering local stakeholders and ensuring that Arizona’s cattlemen, miners, and rural land users have a voice in the planning process,” Sen. Jeff Flake, R-Ariz., said in prepared remarks.

6. Reporting requirements regarding college teachers (H.J. Res. 58).

The rule mandated annual reporting by states “to measure the performance and quality of teacher preparation programs and tie them to program eligibility for participation in the Teacher Education Assistance for College and Higher Education grant program,” Spicer said.

Anne Ryland, a research assistant in education policy at The Heritage Foundation, told The Daily Signal in an email that the rule “gave the federal Department of Education power to evaluate teacher preparation programs at universities, and to link college students’ access to federal financial aid in the form of TEACH grants to the rating of the programs.”

“University programs,” Ryland added, “would be rated based on the effectiveness of their teaching graduates, with effectiveness determined by elementary and secondary students’ test scores and achievement gains.”

7. Regulations on state education programs (H.J. Res. 57).

Congress and Trump rescinded federal rules that “require states to have an accountability system based on multiple measures, including school quality or student success, to ensure that states and districts focus on improving outcomes and measuring student progress,” Spicer said.

The repeal is the first step in “a reconceptualization of Washington’s role in education,” Ryland said.

“These regulations were prime examples of federal micromanagement,” she said. “They were highly prescriptive and highly complex, serving only to put more power in the hands of bureaucrats and to distract schools and teachers from the work of educating students.”

8. Drug-testing requirements (H.J. Res 42).

Spicer said the regulation mandates an “arbitrarily narrow definition of occupations and constrains a state’s ability to conduct a drug-testing program in its unemployment insurance system.”

Four Republican governors—Scott Walker of Wisconsin, Greg Abbott of Texas, Gary Herbert of Utah, and Phil Bryant of Mississippi—wrote Rep. Kevin Brady, R-Texas, chairman of the House Ways and Means Committee, to ask that states be allowed to implement their own policies.

“We believe this rule should be replaced with a new rule that allows increased flexibility for states to implement … drug testing that best fits the needs of each state,” the governors said in the February letter.

9. Hunting regulations for wildlife preserves in Alaska (H.J. Res 69).

These regulations restricted Alaska’s ability “to manage hunting of predators on national wildlife refuges in Alaska,” Spicer said.

In a formal statement, Rep. Liz Cheney, R-Wyo., daughter of former Vice President Dick Cheney, called the rule “another example of the federal government’s determination these past eight years to destroy a state’s ability to manage their wildlife.”

10. Internet privacy rule (S.J.Res. 34).

Published during the final months of Obama’s presidency, the rule sought to force “new privacy standards on internet service providers, allowing bureaucrats in Washington to pick winners and losers in the industry,” Spicer said.

Flake, who sponsored the resolution of disapproval under the Congressional Review Act, said repeal helps keep consumers in charge of how they share their electronic information.

“My resolution is the first step toward restoring the [Federal Trade Commission’s] light-touch, consumer-friendly approach,” Flake said. “It will not change or lessen existing consumer privacy protections. It empowers consumers to make informed choices on if and how their data can be shared.”

11. Rule for logging workplace injuries (H.J. 83).

This rule from the Occupational Safety and Health Administration sought to squelch a more lenient one from the Labor Department. Spicer said the rule “disapproved” of a Labor regulation “extending the statute of limitation for claims against employers failing to maintain records of employee injuries.”

“This OSHA power grab was completely unlawful,” said Rep. Bradley Byrne, R-Ala., chairman of the House workforce protections subcommittee. “It would have done nothing to improve workplace safety while creating significant regulatory confusion for small businesses.”

Through extensive use of the Congressional Review Act, Collins said, Trump is establishing a “legacy” of deregulation.

“I think there’s really a legacy really to be had here,” the Republican congressman from Georgia said.

Congress, with backing from Trump, is making good on promises and saying, “We’re not going to allow our jurisdiction and our constitutional authority to be overrun by the executive branch,” Collins said.

Past administrations from both parties, he said, have not been so devoted to deregulation.

“There was a definite disconnect between the previous administration, and even previous Republican administrations, on doing things on their own and not going through the proper legislative process,” Collins said.

12. Rule preventing states from withholding funds from Planned Parenthood (H.J. Res 43).

By undoing this rule, Congress and the president allow states to opt out of letting federal funds go to Planned Parenthood, the nation’s largest abortion provider.

“This resolution that [Trump] signed today overturns a regulation that was put in place by the previous administration on their way out the door that would have taken away the right of states to set their own policies and priorities for Title X family-planning programs,” Spicer said Thursday.

Undoing this regulation–which became effective days before Obama left the White House–allows states, if they choose, to withhold federal family planning funds or Title X monies from Planned Parenthood clinics and disperse them instead to other health providers.

Rep. Phil Roe, R-Tenn., hailed the change.

“I am proud to support the sanctity of life and to continue to be a strong voice for the right to life,” Roe said in a statement. “States will now no longer be forced to use Title X money to fund Planned Parenthood or other entities that provide abortions.”

“Reversing this will mean that states can continue prioritizing taxpayer dollars for providers who offer real health care to women–not abortions,” Melanie Israel, a research associate at The Heritage Foundation, told The Daily Signal in an email.

13. Rule on retirement savings (H.J. Res 67).

The rule allowed state governments “to trap individuals’ savings in accounts that individuals cannot access or control,” Rachel Greszler, a research analyst at The Heritage Foundation, said.

Promulgated during Obama’s last full month in office, the rule allowed states to create public retirement funds. However, it also eliminated protections from those public plans that initially were covered under a law that set standards for private sector employee pension and health plans.

Critics said the rule removed protections from employees and encouraged employers to drop employees from retirement plans–and put them on the government-run plan–because of high costs.

“Any new employer that’s just starting up is never going to set up their own plan now because why would they do that when they have a cost-free, liability-free option,” Greszler said, adding:

There are costs associated with [creating retirement accounts for employees] and there’s the legal liability with it. So they’re probably going to shift their employees into these plans that have no protections; they can’t make contribution into them … it’s like the Obamacare for savings.

Repealing the Obama-era rule safeguards the retirement funds of individuals who work in the private sector, Rep. Francis Mooney, R-Fla., said.

“This last-minute regulatory loophole created by the previous administration would have led to harmful consequences for both workers and employers,” Rooney said in a formal statement. “Hardworking Americans could have been forced into government-run plans with fewer protections and less control over their hard-earned savings.”

Sarah Sleem contributed to this report.

It has been corrected to reflect that Trump and Congress have used the Congressional Review Act to roll back regulations more than 11 times, and to clarify which regulations are eligible to be undone using the law. It also has been updated to include two additional joint resolutions of disapproval signed by Trump to undo regulations.