For 24 years, Gabe Scuderi had a job, not a purpose.

That changed one afternoon last month when he returned home from the Lysol factory where he works to find his daughter waiting for him. She had been watching news coverage of the coronavirus pandemic and told him that by manufacturing disinfectant spray, he was “literally helping to save the entire world right now.”

Mr. Scuderi, a 54-year-old Italian immigrant, remembers the moment in sharp definition: “It‘s the first time I felt this isn’t only a job. We’re on the front lines now.”

The explosive spread of the coronavirus has transformed the way employees see themselves at the Lysol factory in Somerset County, N.J., owned by U.K.-based Reckitt Benckiser Group PLC.

“Everybody used to say, ‘Oh, it’s just a disinfectant spray,’ ” said Omar Ortiz, who keeps production-line machinery working. “Now it’s like we need it to try to fight back against this virus.”

A century ago, Lysol marketed itself as a weapon against the Spanish flu, which rolled across the planet, killing between 20 million and 40 million people. “Fight Spanish Influenza With Daily Disinfection,” a Lysol ad in the New York Times advised in 1918. “Use Lysol daily to kill germs that are always present in garbage cans, toilets, sinks, drains and in dark, damp, sunless corners.”

Managers at the Lysol plant in New Jersey are urging workers to think of their jobs in the same heroic way. At the end of each shift recently, Saad Islam, head of plant operations, gathered workers from the packaging and processing departments in the cafeteria. They sat at the lunch tables while Mr. Islam, a 38-year-old Pakistan-born mechanical engineer, flipped through PowerPoint slides.

One showed federal data tracking the spread of the coronavirus. Another showed a grocery-store shelf stripped bare of Lysol spray.

“I need everybody’s help,” one manager told Mr. Scuderi and the maintenance team. “This is serious.”

During a normal flu season, the 400,000-square-foot plant dedicates 70% of aerosol production to Lysol. Now, Lysol is the only product rolling off the 250-foot aerosol lines. No more Easy-Off Oven Cleaner. No more Easy-On Spray Starch.

Usually 30 or 40 tanker cars each month pull onto the plant’s rail siding to deliver alcohol, a key ingredient in disinfectants. Today the factory is getting more than 50 railcar deliveries a month to feed aerosol lines that operate 24/7.

“We prepare every year” for the winter flu season, said Mr. Scuderi. “This is something that just came like a storm, like a big wave that just keeps coming.”

Mr. Scuderi met his wife, an Italian-American, when he was 20. She was vacationing in Italy and he was working at the family restaurant. He chased her back to the U.S.

Mechanically minded, he was fascinated by the spray mechanism on Lysol cans and excited in 1996 to find work in the place that fills them with disinfectant and ships them around the country.

These days, he starts his shift at 7:30 a.m. and usually stays voluntarily into the next shift. Six days a week, up to 12 hours a day. “He has been like a man on a mission,” said his daughter, Chantale Wizman.

When he finally drives home, he often notices people spraying Lysol on their mailboxes before retrieving their letters.

Relatives in Italy, a country ravaged by Covid-19, the disease caused by the coronavirus, call to see if he and his family are safe in the U.S.

Jamie Tancredi, 33, started her job as production engineer in the factory’s aerosols department in August.

She used to get a kick out of spotting Reckitt Benckiser brands on store shelves. “Hey, I work at the place that makes that,” she recalls thinking.

Everything has changed since then. Both her father, a plumber, and her bookkeeper mother have lost their jobs to the coronavirus slump, she says.

The pandemic was in full swing when she got a text message from her friend Payal Patel, a chemist at a medical-devices company. Ms. Patel wanted to sanitize her car-door handle and backpack after leaving work but suddenly couldn’t find Lysol in shops. “Jamie,” she wrote, “can you get any cans of Lysol at RB?”

Ms. Tancredi set aside a can for her friend.

Steve Esock, who is in charge of mixing Lysol ingredients, says the coronavirus is worse than the hard days of the H1N1 flu epidemic in 2009 and Superstorm Sandy three years later. “I’ve been through all sorts of situations where the chips are down and the plant comes together and we get it done,” said Mr. Esock, 50, who went to work at the factory straight out of high school.

The company distributed wallet cards to factory employees, in case they’re stopped by police enforcing the state’s stay-at-home order. The cards display the seal of the New Jersey Office of Emergency Management and say the bearer’s “services are considered essential to gubernatorial or federally declared statewide emergency response or recovery operations.”

Nurses check employees’ temperature as they arrive each day at the factory door. Inside, workers wear gloves and safety glasses but haven’t been issued the coveted N-95 respirators, employees say. Some bring surgical masks from home. Workers space themselves out on the production lines. The company wouldn’t say whether any had contracted the coronavirus.

“It feels like we have a responsibility now,” said Mr. Ortiz, 39. “Everybody is counting on us to do our part.”

He has two stepsons, two daughters and a new granddaughter. “I have to make sure I do as much as I can not only for everyone else but for my own family, too,” he said.

Every morning at 5:30, Reza Turki, an Iranian-born forklift operator, stops for a coffee at the Wawa on the way to the factory. Someone inevitably asks him if he can procure some Lysol wipes. The company has given workers a box or two of Lysol spray cans and some wipes for their families and friends. Mr. Turki, 51, gave a can to a pregnant neighbor from Ghana and two more to a Peruvian friend.

“This is tough time for everybody in the United States,” Mr. Turki said. “At least we can help each other, be kind to each other.”

Mr. Turki was an accountant back in Shiraz, Iran. After he reached the U.S. 18 years ago, he found work on the graveyard shift at a UPS facility in Kentucky.

The lure of a job where he could work during the day and sleep at night brought him to Lysol in 2012. He loads pallets of Lysol onto the trucks that stream in and out of the factory, checking a safety diagram to make sure the weight is properly balanced.

Last month, his brother-in-law died of Covid-19 in Shiraz. A trip to Iran wasn’t possible. The factory offered Mr. Turki three days to mourn, he says. He took one day off and then went back to work.

“I’m just trying to be an example for my son,” he said. “I do my part.”

Write to Michael M. Phillips at michael.phillips@wsj.com