South Korea to overhaul livestock drug residue testing, focusing on high-risk substances

South Korea is overhauling how it tests livestock products for veterinary drug residues, shifting from a uniform approach to one that concentrates resources on the highest-risk substances. Under the new system, testing targets and volumes will be set based on a comprehensive assessment of violation history, toxicity and usage levels, rather than applying the same standard across the board.

The Animal and Plant Quarantine Agency announced Monday that it has developed guidelines for risk-priority assessment of veterinary drug residues in livestock products, which will take effect starting with next year's national residue testing plan.

Risk level refers to the likelihood that a substance remaining in livestock products will cause adverse health effects when people are exposed to it. The higher a substance's toxicity or the greater the actual exposure through consumption, the higher its risk level.

The National Residue Program (NRP) is a government-run regime for managing harmful residues — including veterinary drugs — throughout the production and retail of livestock products. The quarantine agency sets the substances, livestock species and testing volumes that provincial animal health laboratories must examine each year, covering products from farms and slaughterhouses.

Currently, about 240 veterinary drugs are tested across livestock species and product categories at farms and slaughterhouses. Testing had previously focused mainly on substances with established maximum residue limits, but the scope expanded significantly after the Positive List System (PLS) for livestock products took effect in 2024.

The PLS applies a blanket default limit of 0.01 milligrams per kilogram to veterinary drugs that lack specific residue limits. With all substances now subject to oversight, the agency recognized the need for an objective framework to concentrate testing capacity on the highest-risk materials rather than treating everything equally.

The agency analyzed roughly 100,000 domestic livestock residue test results per year over the past three years, along with data on veterinary drug usage and livestock production volumes by species. It also drew on practices in the United States and the EU, residue management principles from the Codex Alimentarius Commission, and the WHO's classification of antibiotics by medical importance.

The new guidelines divide the process of setting testing targets and volumes into five steps.

The first step is selecting the substances to be assessed. Priorities are then calculated based on violation and detection records over the past three years, acceptable daily intake levels, and the medical importance of antibiotics. Next, sample sizes are determined by factoring in statistically required testing volumes, livestock production scale and minimum testing thresholds, with volumes then allocated according to risk ranking. In the final step, the testing plan is confirmed after accounting for on-site conditions and policy needs.

The agency expects the new approach to concentrate testing on substances that most need oversight while reducing unnecessary testing of relatively low-risk materials. It also believes the framework will improve testing efficiency and credibility, and help boost the export competitiveness of domestic livestock products by aligning the management system with international standards.

Jeong Seung-gyo, head of the agency's animal disease management division, said the new guidelines are significant because they establish a common standard for determining what to test and how much, based on risk level, in the national residue testing program. "Starting with next year's testing plan, we will concentrate our testing capacity on substances that most need to be managed, and work to strengthen both food safety for the public and the international credibility of Korean livestock products," he said.