1.

Background
 

(1)

The Statutory Framework

Article 38(2) of the Trade Union Act provides that “work to prevent damage to work facilities or the deterioration or decay of raw materials or products shall be carried out normally even during the period of industrial action” (hereinafter referred to as “Preservation Work”). In other words, work necessary to protect the employer’s facilities, raw materials, and products must continue even during a strike. This provision is designed to prevent industrial action from irreparably damaging the very foundation of the business. Despite its importance, the provision’s scope, and in particular which types of work qualify as Preservation Work, has rarely been fully litigated.
 

(2)

The Dispute

In biopharmaceutical culture and purification processes, the raw materials and products are living cells and the proteins those cells produce. Once a process has begun, a stoppage at any stage immediately damages the cells or denatures the proteins, causing the raw materials and products to deteriorate irreversibly. In other words, the affected materials and products cannot be restored once the work stops. On this basis, the Company sought a preliminary injunction asserting that all nine (9) culture and purification processes constitute Preservation Work.

The lower court granted the petition only in part, recognizing only the three (3) final-stage processes as Preservation Work. The Company appealed the partial denial.
 

2.

Key Holdings for the Decision

The High Court held that all nine (9) processes constitute Preservation Work. The Court further enjoined the union from interfering with the continued performance of these processes at the same levels of staffing, operating hours, operating scale, and duty of care before the industrial action commenced.
 
In granting the injunction, the High Court found the requisite need for preliminary relief, citing both the magnitude of the losses the Company would suffer if the processes were halted and the broader societal impact of a disruption in the supply of pharmaceutical products. To ensure the injunction’s effectiveness, the High Court also ruled that any violation of its order would subject the union to penalties.
 

3.

Significance of the Decision
 

(1)

Work That Is Productive in Nature May Qualify as Preservation Work

The central issue in this case was whether work that is also productive in nature can qualify as Preservation Work. The union contended that culture and purification processes are inherently production activities—the very work that a strike is meant to suspend—and therefore cannot constitute Preservation Work.

Kim & Chang, by contrast, drawing on the legislative history and purpose of Article 38(2) of the Trade Union Act, as well as legislation and case law of jurisdictions outside Korea, argued that the test should turn not on the nature of the work, but on whether a stoppage would cause the deterioration or decay of raw materials or products. By granting the Company’s petition in full, including as to the six processes the lower court had excluded, the High Court is viewed as having endorsed this standard.
 

(2)

“Normal” Performance is Measured Against Pre-Strike Operations

The Decision also clarifies what “normal” performance of Preservation Work requires: the relevant processes must continue at the Company’s ordinary pre-strike levels. Preservation Work therefore cannot be reduced to a token, bare-minimum level of activity; it must be performed in substance.
 

(3)

A Preventive Remedy in a Changed Legal Landscape

The Decision is also notable given recent changes in the law governing industrial action in Korea. Traditionally, employers have responded to industrial action by challenging its lawfulness or by suing for damages after the fact. Since March 10, 2026, however, amendments to the Trade Union Act have made proving damage claims by the employer more burdensome and challenging, and the statutory ban on hiring replacement workers during industrial action remains in place. Under these conditions, after-the-fact remedies alone often cannot prevent irreversible harm.

Against this backdrop, the Decision confirms that, even where the industrial action itself is lawful, employers may obtain a preliminary injunction under Article 38(2) of the Trade Union Act to prevent such action from causing irreparable harm in the first place. It also illustrates that such an injunction can be an effective response to industrial action wherever a work stoppage leads directly to the deterioration of raw materials or products. The Decision should therefore provide useful guidance not only for the biotech industry, but also for manufacturers in the semiconductor, chemical, steel, and other businesses whose raw materials or products would deteriorate, or whose equipment would be irreparably damaged, as a direct result of a work stoppage.
 

4.

Practical Considerations

As the mechanism and timing of deterioration or damage caused by a work stoppage can vary from process to process, whether particular work qualifies as Preservation Work must be assessed on a site-by-site basis.

Putting the Decision’s principles into practice therefore requires two parallel efforts. The first is defining the scope of Preservation Work precisely by identifying the specific processes that must continue during a strike, based on a technical understanding of the operations involved. The second is translating that technical analysis into a legal position that can be substantiated in an injunction proceeding. Employers with process-sensitive operations would be well served to undertake this work in advance, so that effective injunctive relief can be secured before irreversible harm occurs.