At a McDonald’s plant outside Mumbai, 200 workers walk through air dryers and disinfectant pools, then get to work making the day’s 25,000 patties from chicken painstakingly sourced in a country with one of the world’s worst food safety records.

To safeguard its multibillion-dollar brand, McDonald’s says more than 100 checks it applies across its international operations are then carried out after that.

India’s tainted water, patchy cold storage network and a retail sector made up of tiny local grocers present a major risk for international food brands, whose reputation can suffer globally from one local slip.

This can mean educating hundreds of small, often illiterate, farmers – critical in a fragmented farming sector that in some cases still uses “night soil”, or human faeces, for composting.

“There are thousands of farmers you need to reach out to, each with maybe an acre, two acres of land,” said Vikram Ogale, who looks after the supply chain and quality assurance for McDonald’s India.

Swiss food group Nestle is currently battling India’s biggest food scare in a decade and an unprecedented branding crisis in the country, after regulators reported some packets of its noodles contained excess lead, a finding the company disputes.

Its woes have laid bare the risks of operating in a country where it is difficult to build a watertight supply chain, and where state food safety infrastructure is minimal, at best.

Nestle uses external audit firms to check suppliers.

Wal-Mart, which operates as a wholesaler in India, says its checks mean rejecting 10-11 percent of produce daily.

Nestle is now pushing ahead with India’s first ever national recall, pulling some 27,400 tonnes of its popular Maggi noodles off India’s shelves, a process that will take at least 40 days.