In this blog post, we will look at the ethical issues of the company and the loopholes in the hazard assessment system, focusing on the Oxy humidifier sterilizer incident.
The Oxy humidifier sterilizer incident is the worst disaster in the history of South Korea, with 239 deaths and 1,528 lung disease patients. The specific causative agents of the disinfectant are PHMG and PHG, which are toxic substances designated as pesticide ingredients in the United States. The shocking fact is that the toxic substances were distributed in the market for 17 years until 2011, when the Korea Centers for Disease Control and Prevention became aware of the situation and began an investigation. Not only the victims but also the people who did not use the product were outraged, which led to a boycott of the company’s products. What was even more shocking was that the products of Oxy, which we learned about in the process, were already readily available items in our daily lives. We were living without being aware of the toxic substances that were close to us.
So, should the public live with toxic substances at the mercy of the companies’ conscience? Of course not. Under current law, toxic substances go through many testing stages before they are sold on the market. This testing stage is called a hazard assessment. Only products with a hazard level below a certain level can be marketed. PHMG and PHG were already designated as toxic substances in the United States, and they had to undergo a hazard assessment to be used as disinfectants. Many people who heard about the Oxy incident criticized the sales company for how it sold toxic substances without a hazard assessment. The shocking fact is that the toxic substances in question underwent a hazard assessment, and the conclusion was “no hazard.”
To better understand the Oxy case, it is necessary to know the steps involved in a hazard assessment. Before that, it is necessary to clarify the terms “harm” and “hazard” used in toxicology. This is because even a slight difference in the spelling of a single letter can have a significant impact on the meaning.
“Excessive accumulation of heavy metals is hazardous,” and “Excessive accumulation of heavy metals is harmful.” There is a clear difference between the two. We all know that “hazard” and “harm” are toxic terms that mean danger. To distinguish the difference between hazard and harm, let’s first look at the dictionary meaning. Hazard refers to the inherent risk of a chemical substance that has an adverse effect on human health or the environment, such as the toxicity of a chemical substance. Risk refers to the risk associated with situations in which hazardous substances may be exposed.
The difference between the two terms may still not be clear from the dictionary definition alone. Hazard refers to the degree to which a substance itself is dangerous, while harm refers to the degree to which the harmful effects of a substance are dangerous to humans when exposed to it. The level of harmfulness is affected by the toxicity of the substance itself and the factors related to exposure to the substance. The latter factors include the possibility of exposure, the duration of exposure, the frequency of exposure, and the intensity of exposure. This is why the hazard of a substance is assessed from the perspective of humans. No matter how harmful a substance may be, it will not harm humans if they are not exposed to it for their entire lives. This is why the toxicity assessment of humans is called hazard assessment rather than risk assessment.
The hazard assessment consists of four major steps: hazard identification, dose-response assessment, exposure assessment, and hazard determination. Hazard identification means identifying the types of diseases and health disorders that may occur. There are various methods for classifying toxicity, but the most representative is acute toxicity assessment. This is distinguished by a toxicity index that shows the magnitude of toxicity in relative terms, called the LD50. The LD50 refers to the dose that kills 50% of the test group when administered to laboratory animals. The acute toxicity assessment is divided into six levels of toxicity, ranging from “practically non-toxic” to “extremely toxic.”
The dose-response assessment is to identify the relationship between the exposure dose and toxic reaction of hazardous substances through animal clinical trials. Hazardous substances with no threshold even at low doses are carcinogens, and substances with a threshold and toxicity at or above the threshold are non-carcinogens. The method of calculating the reference exposure dose varies depending on whether the substance is a non-carcinogen or a carcinogen. The third step, exposure assessment, involves estimating the amount of hazardous substances that are actually exposed to the human body. The effects of the emission area, emission volume, emission time, and the characteristics of the substance itself, such as mobility, degradability, and the human absorption pathway of the hazardous substance, are all taken into account. After that, exposure factors are determined, and information on lifespan, body weight, and average exposure period are quantified and presented. This is used to calculate the final chemical intake.
As such, the hazard assessment is a fairly systematic assessment procedure. However, the issue in the SK chemicals incident arose at the first step of the hazard assessment process, which is the confirmation of toxicity. At the confirmation of toxicity stage, SK chemicals deliberately hid the toxicity by misrepresenting the toxicity. In addition, in the Material Safety Data Sheet (MSDS) prepared on March 6, 1997, SK Chemicals stated that PHMB is a hazardous substance under the Industrial Safety and Health Act and has severe eye and mucous membrane irritation. However, in the patent filed by SK on the 7th, the very next day, it was stated that it is not regulated by the Industrial Safety and Health Act and has low eye and mucous membrane irritation. In other words, the patent also falsely stated its toxicity.
The second stage, the dose-response evaluation, also revealed problems. In this stage of the clinical trial on animals, the results of the inhalation toxicity evaluation of 15 experimental rats were falsified. Professor Cho Mo of Seoul National University, the top authority in the field of toxicology, conducted a hazard assessment by analyzing only the data of the two surviving rats from the inhalation toxicity evaluation results for a monetary reward.
No matter how systematic the risk assessment method is, it is up to people to make this system work properly. Almost all problems with toxic substances are caused by people who do not follow the risk assessment, not by problems with the risk assessment. The price of ignoring the risk assessment specified by law to protect one’s own interests was enormous. Risk assessment is more important because it is directly related to life. In particular, the effects of toxic substances do not appear immediately, but often accumulate in the body. Since the damage does not appear immediately, the cause of the disease cannot be accurately identified and the person is exposed to it for a long period of time. In the case of victims, it becomes difficult to prove that the damage was caused by the item. Even if the damage is proven and financial compensation is received, all that remains is a body already damaged by toxicity.
Even now, people live in fear that there may be products on the market that are being distributed while concealing their hazardousness. In the end, we cannot rely on human conscience and ethics to ensure the safety of the entire population. Only when there is an institutional mechanism to control human greed and corporations can the hazard assessment system play its role properly. Experts in risk assessment should clarify their professional ethics, and each individual in the company should clarify their professional ethics. One alternative is to disclose all experimental data related to the risk assessment process. By disclosing this information, the transparency of the assessment can be ensured and its reliability can be guaranteed. It is urgent to introduce institutional mechanisms for the proper operation of the risk assessment system.
