AUSTIN, Texas – All of Texas’ public universities now allow students with a concealed weapons permit to carry concealed handguns on campus, though each school has marked out exempted areas.

The law, which took effect today, allows individuals to carry concealed guns on public college campuses if they are at least 21 years old and possess a valid concealed handgun permit. The law requires those with the weapons to keep them holstered and out of sight, and also allows schools to map out gun-free zones on campus, Fox News reports.

MORE NEWS: Know These Before Moving From Cyprus To The UK

“For example, at the University of Texas at Austin, teachers will be allowed to declare their officers as gun-free zones, but most will post signs announcing it. Dorm residents can have guns in common areas, such as dining areas and lounges, but not sleeping rooms, where no storage of weapons is allowed. Exceptions to the room restrictions will be made for visiting family members who are licensed to carry handguns,” according to the news site.

“At Texas A&M University in College Station, guns are allowed in dorm rooms and teachers must get permission from the administration to ban guns from their office. State law still bans weapons from some campus areas, such as hospitals and sporting events.”

Texas’ open carry law does not allow the public to openly carry weapons on campus. The new law applies to public colleges and universities, and private institutions can opt out to block students from carrying weapons on campus. All but one of Texas’ private universities – the adults-only Amberton University – have opted to continue a ban on concealed weapons, KHOU reports.

At the University of Houston, school officials have posted signs banning students from carrying weapons in labs, daycares, health care facilities, places of worship, and all university housing except Calhoun Lofts, but also instituted a safe process for students to store their weapons on campus.

The secure storage areas “will be armed by station personnel and open 24 hours a day, seven days a week,” KHOU reports. Lock boxes used by the school incorporate fingerprint scanners to allow only the owner of the weapon to retrieve it.

The new campus carry law took effect Aug. 1, and will spread to community colleges in 2017.

MORE NEWS: How to prepare for face-to-face classes

The Dallas Morning News reports the law sustained numerous legal and political challenges since it was approved by lawmakers last summer, including a still-pending lawsuit by UT professors who want to ban guns from their classrooms.

Texas state Rep. Allen Fletcher told the news site the UT lawsuit is “not going to hold up” in court, and concerns from liberals and professors about the new law are “much ado about nothing.”

Fletcher also believes UT’s move to allow professors to designate their offices as gun safe spaces does not comply with the new law.

“A private citizen will say, ‘You can’t tell me I can’t have my gun in your office,’” Fletcher said. “And then that student will win, because the law is very clear.”

The legislation sparked protests and outrage on college campuses, primarily from professors and university staff, across the state when it was approved last June. Since, many who were initially apprehensive have come around.

Texas Woman’s University, for example, initially expressed concerns about the law, but campus police chief Elizabeth Pauley told the Morning News that after reading the actual law she’s confident it won’t be “too much of a problem at all.”

Others, like University of Texas pre-law student Allison Peregory, believe the new law will make campuses safer. The 21-year-old said she often studies late and walks home through some “kind of sketchy” areas at night that are dimly lit.

“I’m a female student on campus who probably wouldn’t put up too much of a good fight if something were to happen,” she said. “It would be reassuring to know that I was able to protect myself the way I saw fit.”

The effective date of the new law falls on the same day of the 50^th anniversary of a deadly campus shooting at the University of Texas. Some folks have insinuated that the timing is no coincidence, but Fletcher disputed allegations that the start date was designed to send some sort of a message.

“I’m like, ‘Are you kidding me?’ We’ve been working on this for years, and for the implementation to fall on that day — that had never even crossed somebody’s mind,” Fletcher told the Dallas Morning News. “I’m not a young man, but it’s a long, long time since that happened, and I haven’t thought about it for a long time.”