George Laurer had no idea his design would reach well beyond retail outlets when he created the black line and number sets known as the modern bar code while working for IBM as an engineer.

Forty years ago today, Laurer's creation — the Universal Product Code (UPC) — was first put to use in a U.S. grocery store. Since then, a new generation of bar code cataloguing devices has infiltrated multiple industries and even human bodies.

"I did not even envision that happening," Laurer, a Raleigh, N.C., resident who is now retired save for the occasional freelance consulting gig, said to CBC News in an email. "It was designed for the grocery industry. It proved that bar codes … were the way to go."

40 years later, UPC still in common use

On June 26, 1974, an Ohio cashier scanned Laurer's bar code, which was on a 67-cent pack of Wrigley's gum being purchased by a customer, for the first time. The Universal Product Code is still used widely today, mostly in retail stores.

The Smithsonian National Museum of American History once displayed a replica of that 10-pack of gum in one of its exhibitions. It also has one of the first 10 scanners used in the Marsh supermarket where the Wrigley pack was purchased.

The first bar code did not come from Laurer.

Joe Woodland and Bernie Silver created what is affectionately dubbed the bull's-eye bar code — for its circular shape — after the food industry pleaded for someone to develop an automatic checkout system.

Before the UPC, paying for groceries could be tedious. Employees had to manually input prices for every product at the checkout and replace price tags whenever an item's cost fluctuated.

On June 26, 1974, Sharon Buchanan, a cashier at an Ohio supermarket, was the first person to scan a GS1 barcode. (GS1) Despite successful testing of the bull's-eye bar code in an Atlanta grocery store backroom, it did not catch on.

But the grocery store industry continued to push for some type of standardization, so IBM tasked Laurer with designing a standardized bar code. He strayed from the design by Woodland and Silver, opting for a rectangular, picket-fence resembling code.

Printing presses back then could not reproduce the bull's-eye code without smudging it, Laurer explains. His linear code could be arranged so that the inevitable smear only lengthened the code's bars without compromising its reading.

On April 3, 1973, a U.S. panel chose Laurer's design over seven others and designated it the UPC as the only standard for identifying products at the time.

Microchipped IDs, health care

Bar codes, now known by various names, have evolved well past supermarket shelves and into government-issued IDs, hospital rooms and even human bodies.

What is a bar code? A code, usually scanned and read by a machine, that relays information about a product it is attached to. Bar codes can be visually represented in a variety of ways, but the most common UPC code is a set of vertical black lines separated by white spaces with a set of numbers attached to it.

"When we look to the future, the future is really limitless," says Ryan Eickmeier, the senior director of marketing, communications and government relations at GS1. The global, not-for-profit organization designs and manages supply chain standards across the world.

One type of ID system slowly phasing out the bar code, radio frequency identification or RFID, relies on radio waves to identify people or objects. A microchip with an antenna — sometimes the same size as a grain of sand — carries information about the person or product.

While RFID is not a traditional bar code, Eickmeier recognizes it as a modern system of identifying, capturing, sharing and using information — just like the four principles behind the historic bar code.

RFID chips are commonplace in Canadian passports and some provincial drivers' licences now. Ontario and B.C. offer RFID-chipped drivers' licences, allowing for a passport alternative when Canadians cross over the American border by car or foot.

The chips also exist in so-called contactless credit cards, which let users tap their card to a reader instead of inserting or swiping.

GS1 has been working to standardize their use in hospitals to help eliminate human error in patient care.

Toronto's North York General Hospital uses bar code scanning to ensure patients are receiving the right medication, says Eickmeier.

An automated prompt lets a caregiver know if the patient is allergic to a certain type of medication or if they are being administered the wrong dose.

"It's not just, 'Are they giving you the wrong medication?'" he says. "It goes to the food served in hospitals. Is this food right for the patient? Is this patient allergic to peanuts? Is there peanuts in this food?"

RFID chips fixed to hospital equipment can also help administration better track surgical tools and patient equipment, like wheelchairs and crutches.

A bar code for the body

Some companies have even experimented with technologies similar to bar codes inside the human body.

The U.S. Food and Drug Administration once approved — with some limitations — a human microchip.

VeriChip, the size of a grain of rice, was often compared to a pet's microchip. Placed under the skin of a person, it could transmit a 16-digit ID number to a scanner during a medical emergency. First responders or doctors could cross-reference the ID with a patient directory and access the person's medical history, including any drug allergies.

A couple and their then teenage son were the first people to receive VeriChip implants in 2002. Several years later, more than 100 Alzheimer's patients and caregivers received the chip as part of a special project.

But people worried the chips could be used to track them and invade their privacy, and the company, renamed PositiveID Corp., stopped actively marketing the chip in 2009.

An 'internet of things' catalogue

Laurer predicts the UPC system will stay in place for about another decade before the industry opts for a newer system.

He points to the use of QR codes as one new technology revolutionizing the market.

QR codes are squares filled with black and white boxes that can be scanned using a smartphone. They direct the users' phone to a URL.

QR codes are often used by advertisers, but some creative minds have used them to direct prospective employers to their resumés, to inform tourists at museum exhibitions, or to allow shoppers to record personalized messages on gift tags.

But Eickmeier has more hope in the UPC's lasting power, saying the industry has already invested in the technology necessary to use the classic bar code

"The next 40 years are really the exciting part of what can we continue to do with it," he says.

One such project is GS1's 'internet of things,' which Eickmeier says he hopes will be available to the public within the next five years.

The massive database would allow customers to scan bar codes and receive information on a product's nutrition and allergens, among other things.

While some smartphone apps already provide this service, their information is crowdfunded and not as trustworthy, Eickmeier claims.

"I think the bar code will always have a use ... in the industry," he says. "It will just have to kind of evolve with time."