The ‘Isothiazolinone Story’

Genetic validation of Aspergillus fumigatus phosphoglucomutase as a viable therapeutic target in invasive aspergillosis

“…ISFP1 contains an isothiazolone ring that is known to react with cysteine thiols as has been demonstrated for several proteins ( Table S4 ) involved in a range of biological processes ( 101 ). As a consequence, isothiazolones are biocides against several classes of organisms ( 128 , 129 , 130 ). For instance, isothiazolones inhibit the growth of Aspergillus niger and C. albicans with MIC ranging from <0.01 to 100 mg/l ( 131 , 132 ), although the mechanism of lethality is unknown.…”

“…Similarly, while we have observed in preliminary experiments that ISFP1 inhibits the growth of A. fumigatus with an MIC of 10 mg/l, it is not clear if this is (solely) through inhibition of Af PGM. Due to their biocidal activity, isothiazolones have long been utilized as industrial biocides for cosmetic products ( 128 , 133 , 134 ). Recently, several studies have raised concerns about the safety of isothiazolones.…”

The sensitizing potential of various biocides in the guinea pig maximization test

“…In this study, patch testing with isothiazolinones in guinea pigs clearly indicated that these compounds have an important allergic potential, except for BIT, and these experimental results correlate closely with the high percentage of people sensitized by these compounds (5). Indeed, isothiazolinone derivatives are frequently used and are now marketed under more than 30 trade names (13). Thus, up to 80% of water‐based paints contain MCI/MI, and a large proportion of the general population has been exposed over long periods of time to these compounds, meaning that MCI/MI became one of the top 10 contact allergens in Europe (14).…”

Increasing the effectiveness of a liquid biocide component used in antifungal waterborne paints by its encapsulation in mesoporous silicas

“…Isothiazolinone-based biocides are very commonly used in the coating industry for growth inhibition of bacteria, fungi and yeast [10,11]. A typical commercial waterborne paint formulation used in the coating industry consists of an aqueous mixture of different ingredients, where both 5-chloro-2-methyl-4-isothiazolin-3-one (CMIT) and 2-methyl-4-isothiazolin-3-one (MIT) are present in a CMIT/MIT = 3 wt ratio [12]. Nevertheless, the expected increase in restrictions on the use of toxic biocides, coupled with the increased public awareness of air pollution, will reduce their consumption [13].…”