Photo/Illutration Hideo Kawaguchi, chief developer of the “3K” salt jelly, in the offices of Sanwa General Contractor Inc. in Osaka’s Yodogawa Ward on July 6 (Takashi Nakajima)

OSAKA--With construction workers at high risk of heatstroke during Japan’s sweltering midsummer, one company in the industry here has come up with a drink that protects those toiling onsite in the intense heat.

To keep construction workers cool, Sanwa General Contractor Inc. developed a jelly drink that provides them with the salt they need to prevent heatstroke. 

“I believe eliminating heatstroke from construction sites is our way of contributing to society, because doing so reduces the trouble we cause to medical workers, who are under pressure to deal with COVID-19,” said Hideo Kawaguchi, 46, the leader of the product’s development team.

Construction industry casualties from heatstroke topped those in all other industry types between 2016 and 2020, health ministry data shows, with 847 heatstroke patients, 39 of whom died, followed by the manufacturing industry, with 806 patients and 15 deaths.

The pandemic may further raise the risk of heatstroke at construction sites as workers often wear face masks to protect themselves from catching COVID-19.

Sanwa, based in this western Japan city, pledged to become a “top runner in the effort to block heatstroke at construction sites” about five or six years ago.

The outcome of its efforts is a product called “3K salt jelly made by a general contractor.” 

Though “3K” refers to its three ingredients: konnyaku (konjac), koragen (collagen) and shiro-kikurage (snow fungus), 3K is also a phrase describing the deep-rooted negative image of the construction industry: “kitsui” (difficult), “kitanai” (dirty) and “kiken” (dangerous).

Sanwa chose the name partly out of the desire to dispel that image by making a product that is not only useful but also tastes good.

Getting it to taste that way wasn’t easy, however.

Sanwa teamed with Iwase Cosfa Co., a Tokyo-based processor of nutritional food products that it once built a warehouse for, to develop a jelly that helps supplement salt to the body.

The project kicked off in February 2020. A trial product was used at Sanwa’s construction sites in the summer of that year.

They paid particular attention to the taste, but many of their concoctions flopped. Among the prototype products they attempted were tomato, cucumber, perilla, cow’s milk and yogurt.

In spring 2021, they completed their final product, a 10-gram stick-shaped pack of the jelly that allows an intake of 0.15 gram or so of salt, available in five flavors, including lychee and grape.

The developers also admixed it with konjac ceramide, collagen and snow fungus, an edible mushroom that grows on trees, which is rich in vitamin D, to counter skin damage from ultraviolet rays.

Sanwa, founded in 1947, had taken a variety of other measures to prevent workers from getting heatstroke before it started working on the drink.

The small to midsize general contractor, with only about 150 employees, had construction site restrooms equipped with air conditioners and built shower facilities so workers could cool off during their lunch breaks.

The company, which has built plants, warehouses and distribution centers, among other types of structures, also tried having its workers take commercially available salt tablets, dried umeboshi pickled plums and other food products to ingest salt.

But those products failed to become popular with the workers. Some of them complained they sucked the moisture out of their mouths. Others said they had an aftertaste that lingered too long.

But things have gone better for the jelly drink that Sanwa co-developed, interest in which rapidly spread by word of mouth within the construction industry, leading Sanwa to receive requests to start selling the product.

“I hope those working in the sweltering heat of midsummer will get it over without a hitch,” said the drink’s development team leader Kawaguchi, who has also worked as a foreman for 15 years.

The 3K salt jelly can be purchased on Sanwa’s e-commerce website on the “Stores” platform, where a set of 100 packs sells for 4,104 yen ($37), including tax. Delivery is free.

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