Properties of Polyhexamethylene Guanidine (PHMG) Associated with Fatal Lung Injury in Korea.

Dong-Uk Park,Jihoon Park,Kee Won Yang,Ju-Hyun Park,Jung-Hwan Kwon,Han Bin Oh

doi:10.3390/molecules25143301

Abstract

The use of humidifier disinfectant (HD) has been determined to be associated with lung injuries (HDLI) in Korea. Although HD brands containing polyhexamethylene guanidine (PHMG) oligomers have been found to cause more HDLI compared to brands containing other disinfectants, the physicochemical properties of PHMG have been poorly defined. We aimed to quantify the PHMG dissolved in HD brands, characterize the number-average (Mn) and weight-average (Mw) molecular masses, and identify the polymerization degree of PHMG. Analysis of the PHMG oligomers was performed using a matrix-assisted laser desorption/ionization time-of-flight mass spectrometer (MALDI-TOF MS) operated in positive-ion reflectron mode. Eight brands of HD containing PHMG were identified. The PHMG concentrations in these brands ranged from 160 to 37,200 ppm (mean = 3100.9 ppm). Concentration was a significant variable among and within HD brands. The degree of PHMG oligomerization fell within the range of two to four. The averages of Mn and Mw were 517.2 g/mol (range: 422–613 g/mol) and 537.3 g/mol (range: 441.0–678.0 g/mol), respectively. Based on the average molecular weight and the degree of polymerization, the PHMG examined here could be regarded as oligomers, which may be associated with the highest proportion of HDLI being caused by PHMG.

Highlights

Several types of chemicals were widely used as humidifier disinfectants (HD) in South Korea from 1994 until the end of 2011
The objectives of this study are to quantify the concentrations of polyhexamethylene guanidine (PHMG) dissolved in HD brands
A total of eight HD brands have been identified as containing PHMG

Summary

Introduction

Several types of chemicals were widely used as humidifier disinfectants (HD) in South Korea from 1994 until the end of 2011. The use of HD brands containing polyhexamethylene guanidine (PHMG), oligo (2-(2-ethoxy) ethoxyethyl guanidinium (PGH), and a mixture of chloromethylisothiazolinone (CMIT) and methylisothiazolinone (MIT) has been confirmed to be associated with lung injury, including interstitial pneumonitis and widespread lung fibrosis. This has been named humidifier-disinfectant-associated lung injury (HDLI) [1,2,3]. Molecules 2020, 25, 3301 the government has operated the Humidifier-Associated Lung Injury Investigation 2and Decision.

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