The recall was triggered after members of the public complained that one of its frozen pizzas smelled of petroleum oil or machine oil.
When the company checked the samples sent back by customers, it found some of them contained malathion, an insecticide used in agriculture
The firm is currently in the process of recalling 88 products produced at its Aqli Foods Co. plant in Gunma Prefecture, northwest Japan.
The plant manufactured 42 products for the general market as well as 46 products for industrial use, including for school meals.
“We are making an all-out effort to investigate, but are still unable to specify the cause at this moment,” the company said in a statement.
No reports of serious illness have been confirmed.
Diarrhea and nausea
Malathion has relatively low toxicity levels for humans, but exposure and ingestion can cause diarrhea and nausea.
According to the company, 42 of the products were sold at retail outlets while the other 46 were supplied to restaurants.
The local health authority has carried out an inspection of the plant and could not find any signs of malathion at the factory.
Maruha Nichiro Holdings is one of the nation’s largest seafood processing companies.
“A check was made of the chemicals and raw materials used at the plant, but the pesticide was not found,” a company official said. “We will look into not only the manufacturing process, but also the possibility that the products were tainted outside of the plant.”