As the United Automobile Workers union seeks to organize Tesla’s Fremont car factory, some employees say they never received proper training to handle hazardous chemicals they blame for causing rashes, dizziness, nosebleeds and, in one case, eye damage — an accusation the company calls “completely false.”

An organizing committee of Tesla employees has spoken with 22 workers raising complaints about chemical training and handling within the bustling plant, which is revving up production of Tesla’s latest electric car, the Model 3.

“This is just one of many issues, but it’s one of the scarier ones,” said Jonathan Galescu, a repair technician at the factory and member of the organizing committee.

Some employees say their training on use of the chemicals — including one that can cause birth defects — was limited to warnings from supervisors not to let the substances touch their skin and, in case of contact, wipe the chemicals off with a rag and water or alcohol.

California law requires companies that use hazardous chemicals to give employees training on the proper handling of those materials and make available detailed information on their potential dangers.

“I’ve only been trained through the Internet and the union on how to deal with the chemicals,” said Dennis Cruz, who has worked on the factory’s auto body line since 2014. Residue from an adhesive used within the cars, he says, caused chemical burns in his eyes after he rubbed them at the end of a night shift.

“I was like a blind person bumping into walls — I had to count the steps to the bathroom,” said Cruz, 41.

Tesla, however, says it follows all local, state and federal labor laws, and regards the questions about chemical safety as another attempt by the union to pressure the company.

Tesla says that all employees who handle potentially hazardous chemicals must undergo training on how to handle those substances, as well as wear any personal protective gear recommended by the product’s manufacturer. In addition, every new employee must attend orientation sessions that include health and worker safety training, down to learning how to read hazard warnings on product labels.

“Anyone who does not complete this orientation does not become a Tesla employee,” a Tesla spokesman said in an email.

The company accused union organizers of spreading misinformation both inside and outside the factory.

“Given the UAW’s overwhelming election loss at a Nissan plant earlier this month, the recent corruption charges leveled against union leaders who misused UAW funds, and the fact that their efforts have failed to gain any traction with our employees, it’s no surprise that the union is feeling pressured to continue their public relations campaign against Tesla,” the spokesman said.

Galescu, two other Tesla employees and the union complained to the federal government in April that Tesla was trying to prevent its workers from distributing pro-union flyers, alleging intimidation. The Oakland office of the National Labor Relations Board on Thursday ordered Tesla to respond by Sept. 14 and scheduled a hearing for Nov. 14. Tesla, in a statement, called the allegations baseless and “meant only to generate headlines.”

In May, the Worksafe occupational safety group in Oakland released a report on accident rates at the plant, after the UAW and several Tesla employees who want to join the union raised complaints about workplace conditions. The report found that Tesla’s Fremont factory in 2014 and 2015 suffered a higher accident rate than the auto industry’s average. Tesla countered that its accident rates have substantially decreased since then.

The complaints about chemical safety suggest that Tesla’s factory operations do not adequately protect workers from known hazards, said Mike Wilson, director of the Occupational and Environmental Health program at the BlueGreen Alliance, a coalition of environmental groups and unions pushing for a cleaner economy.

Wilson, a former chief scientist in the California Department of Industrial Relations and director of UC Berkeley’s Labor Occupational Health Program, interviewed some of the affected Tesla workers at the UAW’s request, although the UAW is not part of the Alliance.

“What we’ve seen in these cases is this persistent pattern of employees describing a pretty striking lack of controls in the workplace, things I would describe as routine industrial safety practices that just don’t appear to be there,” he said.

For nearly two years, Charley Briese had to apply an adhesion promoter to auto parts, squeezing it from a clear bottle. Sometimes the chemical would spray out, particularly if the bottle had been sitting unused overnight, and the adhesion promoter would land on her clothes and skin. It itched and burned, she said.

It also produced a strong, sweet smell that gathered in the work space. She began experiencing vertigo, numbness, nosebleeds and what Briese describes as “borderline fainting spells.”

Briese recalls signing papers when she was hired stating that she understood she would be working around potentially dangerous chemicals. But she says she was not given any training or information on the adhesion promoter, nor was it named on the bottles she used. Its label, however, was on larger bottles used to refill the ones she used.

It turned out to be a 3M product whose safety data sheet, a standardized description of a chemical’s potential hazards, warns against breathing in the fumes, saying it should be used only in a well-ventilated area. The adhesion promoter, according to the data sheet, can cause dizziness, affect fertility, damage fetuses and prove fatal if it is swallowed and enters the airways.

Briese requested work assignments elsewhere in the factory to get away from the chemical. That helped her symptoms, but they only went away after she went out on leave with a shoulder injury. She returned to the plant earlier this month and wants Tesla to use an alternate chemical.

“If it’s possible to stop using it, that would be ideal,” said Briese, 21. “But if not, we need education on what it is and the dangers.”

Tesla says it has extensively monitored workplace exposure to the adhesion promoter, finding that exposures were “effectively controlled” and below regulatory limits. The company also held meetings with employees to explain those findings and answer questions about the product’s safe use.

Cruz says an adhesive used to bind parts together got into his eyes after he absentmindedly rubbed them in December. Within days the eyes grew painful, filled with mucus and pus and became difficult to open, he said.

“I had a 4-year-old (son) going, ‘Daddy, look at me,’ and I was like, ‘I can’t,’” he said.

A doctor told him he had suffered chemical burns on the eyes. Although the mucus and pus are long gone, he says he still has to take eye drops daily.

Tesla says that employees who work with that adhesive undergo specific training for its use. Cruz says he was not trained how to use the product but was told to try to avoid touching it. In case of contact, he says, he was told to clean it off with a rag or, if necessary, wash it off in the bathroom. The product’s safety data sheet calls for washing it off with soap and water, and in the case of eye contact, rinsing the eyes for several minutes.

Wilson said the Tesla employees he met generally did not realize the potential long-term harm these chemicals can cause.

“Charley came with complaints of nosebleeds, but the real danger was reproductive toxicity,” Wilson said. “Sitting there, talking with these folks, they didn’t understand the magnitude of what they were telling me.”

David R. Baker is a San Francisco Chronicle staff writer. Email: dbaker@sfchronicle.com Twitter: @DavidBakerSF