In his first year working as a cleaner in a foodcourt 10 years ago, Mr Rick Lee, 48, accidentally knocked into a patron and splashed gravy from a bowl on the middle-aged man's white shirt.
The patron was livid and shouted at Mr Lee: "This is branded, you know? I paid $200 for it. I was going to a nice dinner, but you dirtied my shirt. You have to pay for it."
The stain was the size of a golf ball, and Mr Lee believed it would be removed after a wash. But the patron was insistent, so Mr Lee bought him a new shirt that cost about $50, took the dirty shirt off the man's back and got it dry- cleaned by the next day.
Mr Lee and other cleaners tell The Sunday Times that they and their co-workers have encountered unreasonable behaviour from customers.
He says: "We have to 'lower' ourselves and apologise, even if it is not our fault. We have no choice. That's the way it is in the service industry."
The spotlight has been cast on the verbal abuse cleaners are sometimes subjected to, following an incident that happened about a week ago at Jem mall's foodcourt. A deaf and mute cleaner, Mr Png Lye Heng, 64, was yelled at by a woman because he cleared her food before she had finished her meal.
A video, which later went viral, shows the woman lashing out at a manager of the company providing cleaning services to the foodcourt when he tried to explain that his worker was deaf and mute.
Operations manager Winson Soh of cleaning firm Horsburgh Engineering says confrontations between patrons in hawker centres or foodcourts and deaf cleaners are quite common.
He explains that while deaf cleaners have no speech impediments, they are used to communicating with grunts or by gesticulating.
"But the patrons cannot see anything wrong with them, so they get offended and wonder why the cleaner can't just speak to them properly and ask to clear their food," Mr Soh, 40, adds.
Some patrons then end up shouting at the cleaners in anger. Mr Soh says he watches such employees closely and intervenes quickly when a negative situation arises.
Able-bodied cleaners also get scolded for clearing patrons' food when they are not done.
Mr Lee, now a cleaning supervisor employed by Sergent Services, says cleaners are instructed to clear food that is left unattended for 10 to 15 minutes. But some patrons leave their food at the table to buy drinks, which sometimes takes a while.
"They get angry when they return and find their food gone. Some demand that we replace the meal," he says, adding that he has done so in the past.
Cleaners say they also often find themselves on the receiving end of unkind remarks and allegations.
Once, Mr Lee heard a woman telling her son when he was cleaning their table: "If you don't work hard, you will end up like him."
He was hurt, but let it slide. "I tell myself that I am earning an honest living. I am not begging or stealing," he says.
When things go missing, however, cleaners say they are the first to be accused.
Mr Thomas Lee, 48, manager of cleaning firm Friendly Supplies, says: "The question, 'Did you take my things?', is offensive to my staff."
Cleaning managers say the accusers usually do not apologise after the cleaner is found to be innocent.
The cleaners find different ways to deal with the challenges at work.
Madam Soh Ai Kim, 60, recounts that an office employee told her not to touch her bag when cleaning the area because her hands were not clean. "I was hurt, but I just wore a pair of gloves after that," she says.
Those who are told that they have body odour try to change their uniforms multiple times a day.
Mr Mohamed Kahir, 52, who is now in a supervisory position with cleaning firm ISS Facility Services, says he simply nods quietly and smiles when the other party is being unpleasant or unreasonable.
"I try to be humble, and I never go into a direct challenge," he says.
His positive attitude has paid off. He has won awards and certificates of commendation from customers. "I'm proud of the work I do," he says.
"Cleaners are important to the society. We do the dirty work for you that you do not do yourself."