Samsung Biologics Union Starts a 3-Week Partial Strike: Why Only 400 Walk Out

The labor union at Samsung Biologics, a major South Korean contract drug manufacturer, began a partial strike at midnight on November 6 that is set to run until November 27, about three weeks. Only about 400 of the union's roughly 4,000 members are taking part. The union had planned a full walkout, but a court order requires nine core production processes to keep running during any strike, so the action is limited to support roles. The dispute is about pay: the company offers a 6.2% base pay raise, while the union wants 9.5% plus a bonus pool equal to 15% of operating profit.

What Samsung Biologics does

Samsung Biologics is a contract development and manufacturing organization, or CDMO. In plain terms, it develops production processes for other drug companies and then makes their biologic medicines at large scale at its plants in Songdo, Incheon, west of Seoul. Biologic drugs are made by growing living cells, so production lines cannot simply be paused and restarted without risk to the material inside them. That technical detail turned out to shape this strike.

Who is striking

According to the union, its members make up about 70% of the company's workforce. About 10% of them, roughly 400 people, are joining this strike. They work in quality control testing, quality assurance, logistics and indirect support roles in production. There are no rallies; members simply stop working. The union says it is reviewing whether to widen the strike later. The company said it keeps the door open for talks and will do its best to keep processes running and product quality stable so that patients and customers are not affected.

This is described as the union's second partial strike. It held a partial strike in late April and a full strike from May 1 to May 5 that involved about 2,800 members, followed by a work-to-rule campaign in which members refused overtime and holiday work.

The court order behind the narrow strike

The company asked a court to bar strike action in key processes. On October 16, an appeals panel of the Seoul High Court expanded the list of protected processes from three, set in the first ruling, to nine. They are flask culture, bioreactor culture, harvest, media preparation and supply, chromatography, virus filtration, concentration and buffer exchange, drug substance filling, and buffer preparation and supply. The court judged that these tasks must continue with normal staffing and hours during a strike to stop materials and products from spoiling. Each violation carries a payment of 20 million won to the company.

A quick note on the legal tool: an injunction against industrial action is a temporary court order, issued before any final ruling, that bars a union from striking in specified tasks. It does not decide who is right in the pay dispute. It only limits where a strike can happen while the dispute continues, which is why the union could still strike in other departments.

The result is that the core production chain keeps running while surrounding work stops. In our view, this is a clear example of how labor disputes look different in industries where production cannot be halted safely: the court, not just the union, effectively set the size and shape of the strike.

How big is the pay gap?

The gap between the two offers is 3.3 percentage points of base pay. To make that concrete, we ran a simple calculation using an assumed monthly base salary of 4 million won (about $2,950 at 1,357 won per dollar). Under the company's 6.2% offer, the raise would be 248,000 won a month. Under the union's 9.5% demand, it would be 380,000 won. The difference is 132,000 won a month, or about 1.58 million won over 12 months. This is an illustration only, since actual base pay differs by employee.

Base pay also matters more than a one-off payment because future raises are calculated on top of it, so a gap in the base rate tends to compound over time. The union's demand for a bonus pool tied to 15% of operating profit could be an even larger number, which is why that item is a second front in the talks.

What to watch next

The two sides failed to agree after mediation broke down on March 23 and later government-brokered talks. A bargaining session scheduled for November 3 did not take place after the company asked for a delay, citing trust issues, and the union called that a unilateral breakdown of talks. The union says it will keep requesting negotiations and may extend action to production processes in stages if the company does not respond.

With core processes running, near-term production disruption may be limited. However, quality control testing is the step a drug must pass before it ships, so a longer strike could put shipping schedules in focus. The key things to watch are whether bargaining resumes before the strike ends on November 27 and whether the union widens its action.