Hawaii has long had one of the lowest rates of gun violence in the country, thanks in part to our famously tolerant culture and strict gun laws. It’s a status worth protecting. So it behooves the state to challenge decisions involving guns that threaten our public safety.

One of them is the July 24 decision by a federal appeals court panel nullifying Hawaii’s tough restrictions on “open carry” — the ability to openly carry firearms in public.

Another is a settlement reached with the U.S. State Department that would allow a company to post online blueprints for making unregistered, untraceable and undetectable plastic guns using 3-D printers.

The state is considering appealing the open-carry ruling, as it should. But it already has joined 18 other states and the District of Columbia to challenge the 3-D printed guns settlement. A federal judge in Seattle temporarily blocked the company, Defense Distributed, from posting the blueprints.

It’s not at all clear whether the states will succeed in blocking the 3-D gun plans. There are important, possibly conflicting interests involved: the states’ interest in public safety, the First Amendment’s guarantees of free speech, and gun ownership rights under the Second Amendment.

Still, Hawaii, along with the other states, are correct to pursue their challenge. They need to know, and perhaps help determine, where the legal line should be drawn.

An unfettered ability to print working firearms at home, effectively bypassing state and federal laws regulating them, poses a unique danger that should not be underestimated.

The manufacture and ownership of plastic-only guns is already illegal under federal law, and for good reason. Metal detectors can’t detect them — an attractive feature for criminals and terrorists.

But just the blueprints themselves? Defense Distributed argues that distributing the plans constitutes speech, and preventing their distribution amounts to illegal prior restraint and a violation of the First Amendment’s freedom of speech protections.

Legal experts will concede that Defense Distributed has a point. It’s not hard to find instruction manuals that provide recipes for making dangerous objects. One of the most famous, The Anarchist Cookbook, teaches how to make Molotov cocktails, among other things. Why should 3-D gun instructions be treated differently?

It doesn’t appear that Cody Wilson, who created the blueprints, did so simply to exercise his right to free expression. He expects his guns to be made.

“I think the state should be as weak as possible relative to the individual,” he told The New York Times. “The proper posture of the state is one that at least is in fear of its citizen, not one that lords over it.”

The states argue that making it easier to obtain an illegal firearm by distributing the blueprints violates the states’ Tenth Amendment authority to exercise its police power and enforce public safety laws, including those regulating guns.

Plastic 3-D guns may not seem like much of a threat. They are often unreliable, prone to exploding, and still require some metal parts to work. It’s easier to get a regular gun. Besides, hobbyists have been manufacturing their own guns for years, using parts ordered online.

But no one expects the 3-D printing technology to remain in its current state; the technology will improve and presumably, so will the guns. Faced with such a possibility, it’s worth arguing that the computer code is an object, not speech, and thus subject to closer regulation.

President Donald Trump himself sounded somewhat skeptical of Defense Distributed’s case. In a July 31 tweet, he said, “I am looking into 3-D Plastic Guns being sold to the public. Already spoke to NRA (National Rifle Association), doesn’t seem to make much sense!”

Indeed, it doesn’t.