- Introduction: Burden of proof in product liability cases under Korean law
Like the common law, Korean law holds a party subject to strict liability where such party is responsible for a product defect that caused personal injury and property damage. This no-fault liability is acknowledged based on the principle of equity to protect the general public and consumers, who are at a disadvantage in litigation due to the lack of professional knowledge and difficulty in collecting evidence to prove their case.
However, in cases where criminal liability is at issue, the principle of strict liability based on the principle of equity does not apply. Unlike civil trials, criminal trials aim to discover the evidentiary truth and operate based on the principle of criminal liability (actus reus). Thus, the prosecution has the burden of proof to demonstrate the elements of the crime beyond a reasonable doubt, including causal relationships.
- Example of product defect in household chemicals: humidifier disinfectant case
Beginning in 2011, an outbreak of product defect claims related to a particular household chemical – humidifier disinfectant – shocked the Korean public. Named as the world's first “biocide case,” a series of claims regarding humidifier disinfectant products has been extensively covered by the Korean media in response to public concerns.
The claims surfaced when many users of humidifier disinfectant products began to show symptoms of severe pulmonary disease. The medical staff of a university hospital recognized the significance of the phenomena and reported the issue to the Korea Disease Control and Prevention Agency (KDCA), which initiated an epidemiologic investigation concerning the humidifier disinfectant products.
Through the investigation, it was presumed that chemical substances in the humidifier disinfectant used to prevent the growth of microorganisms within the humidifier products may have caused the disease. Following the investigation, toxicology tests were conducted to ascertain the impact of the humidifier disinfectants on human health.
As a result, the humidifier disinfectant products on the market at that time were classified into two types: (i) products comprised of cationic polymer substances, PHMG and PGH Product group (Type A); and (ii) products comprised of non-ionic monomolecular substances called CMIT and MIT (Type B). An example of Type A disinfectant was a product manufactured and distributed by Company O using the raw material supplied by Company S. An example of Type B disinfectant was the humidifier disinfectant product supplied by Company S and distributed and sold by Company A. According to animal inhalation tests conducted as part of the investigation efforts, a distinct difference was that Type A disinfectants were found to have a causal link to the lung injuries. In contrast, Type B disinfectants were not found to have such a causal link. As such, a compulsory recall of six product containing Type A components was carried out. As for Type B products, although Type B had no confirmed toxic effects on the human body, manufacturers and distributors such as Company A voluntarily recalled and banned the sale of the product in their efforts to respond to the public controversy.
- Results of criminal proceedings of the humidifier disinfectant case
In 2016, based on the aforementioned results of the KDCA's experiments, the prosecution indicted the executives of Company O on the charge of death and/or injury by occupational negligence1. On January 25, 2018, the defendants were found guilty of death and/or injury by occupational negligence as the court acknowledged their breach of duty by failing to verify the safety of the Type A product.
While the executives of companies involved with Type B products (e.g., Company S and Company A) were excluded from the 2016 indictment, the prosecution reopened the case based on additional experiments conducted by the Ministry of Environment later in 2018. In 2019, thirteen executives of Company S and Company A were indicted on the charge of death and/or injury by occupational negligence.
In January 2021, the Court held that there was insufficient evidence to prove a causal link between the use of Type B products and the occurrence or aggravation of the pulmonary disease and asthma suffered by the claimants (insufficient “causation”). Accordingly, the defendants were acquitted without the court further determining whether there was a breach of duty or not.
The prosecution subsequently appealed, and the appeal is currently pending.
- Importance of the causation element in criminal proceedings regarding household chemical product defect cases
As seen in the above case, for crimes of death and/or injury by occupational negligence against corporate executives for injury caused by household chemical products generally have issues of proof from two aspects.
- “Causation” element: There must be sufficient evidence that inhalation of Type B substance caused death and/or injury suffered.
- “Breach of Duty” element: There must be sufficient evidence that the relevant corporate executive has breached his or her duty to verify the product's safety and foreseeability of damages on human bodies.
It is noted that for crimes of death and/or injury by occupational negligence related to chemical products, the causation element would need to be dealt with prior to the breach of duty element. This is in contrast with the criminal cases of occupational negligence resulting from general (non-chemical) product defects, where most of the time the existence of the defect and the link to the resulting injury are easily proven, thus making the breach of duty element practically the more important element to dispute or defend.
However, when it comes to household chemicals, the causation element is particularly important and must be satisfied prior to the breach of duty element, because a biocide that removes bacteria innately has the toxicity that may or may not be toxic to the human body depending on the degree of exposure or method of usage. Thus, it must first be confirmed that such chemical substance in fact has the ability to cause the injury suffered. Furthermore, such causation element is further split into two separate parts as seen in below: general causation and individual causation.
- “General Causation” element: There must be sufficient evidence that the household chemical substance in question is able to cause the disease or injury suffered (likeliness), and this should be proven by ample scientific evidence.
- “Individual Causation” element: There must be sufficient evidence without reasonable doubt showing that the individual victims (claimants) have used the household chemical substances, have been exposed to the toxicity of the chemical substances, and have suffered symptoms leading to death and/or injury without the intervention of other causal factors.
The above two “causation” elements must be satisfied beyond the reasonable doubt before moving on to disputing the breach of duty element. In other words, if such causation element is not satisfied, there is no need to question whether there was a breach of duty . Thus, the decision by the court of the first instance to acquit the defendants for Type B products can be understood in this vein.
As a matter of principle, the prosecution needs to prove both the general and individual causation elements. As for the defense counsel, the following factors and pieces of evidence play important roles in relation to the above “causation” elements:
- In-depth understanding of the legal importance of the
“causation” element and obtaining the relevant
supporting evidence:
- Securing scientific evidence that raises reasonable doubt on the credibility of the prosecution's scientific evidence that is used to prove the toxicity of the chemical substance;
- Deducing technical, structural, or calculation errors in the evidence through the analysis of experiments, studies, papers reports, and/or any other materials relied upon by expert witnesses such as professors, doctors, and researchers, and thereby raising reasonable doubt on the conclusions deduced from the prosecution's evidence.
- Reviewing the existence of any potential independent causes that may have led to the injury suffered, such as the existence of underlying diseases or history of past exposure to other unrelated toxic substances.
In sum, unlike the regular crimes of death and/or injury by occupational negligence where a breach of duty is usually the main issue, for the same crimes related to household chemical products – in particular related to the toxicity of biocide – the causation element (both general and individual) plays a much more critical role.
Footnote
1 The elements of the crime of death and/or injury by occupational negligence are: (i) foreseeability and breach of duty; (ii) death and/or bodily injury; and (iii) causation between (i) and (ii).
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.
