Table 3.

The virucidal activity of chlorine-releasing disinfectants and chlorine dioxide against SARS-CoV-2.

Product/Active Ingredient	Production Type	Concentration	Disinfection Phase	Contact Time	Reduction of Viral Infectivity (log10)	Reference
Trichloroisocyanuric acid (TA)	Disinfection solution (mixed with ethylene glycol as antifreeze)	≥1000 mg/L	Carrier test on cloth (−20 °C)	5 min	4	[58]
	Disinfection solution	250 mg/L	Suspension test (with organic matrix)	5 min, 10 min, 20 min	3.25, 4.0, ≥4.75	[24]
		500 mg/L		30 s, ≥5 min (5 min, 10 min, 20 min)	3.58, ≥4.75
		1000 mg/L		30 s, 5 min, 10 min, 20 min	≥4.75
Sodium hypochlorite (NaOCl)	Disinfection solution	0.5% (v/v)	Carrier test on stainless steel (with organic matrix)	30 s, 1 min	2.03, 3.45	[30]
				5 min, 10 min	>4 *
	Wipe			0–5 min drying post-wiping	>4 *
	Disinfection solution	80 ppm	Suspension test	10 s–3 min	>4	[78]
		8 ppm		10 s–3 min	2–3
		0.8 ppm		10 s–3 min	1
		80 ppm	Suspension test (with organic matrix)	10 s–3 min	>4
		8 ppm		10 s–3 min	1
		0.8 ppm		10 s–3 min	1
84 disinfectant (NaOCl)	Disinfection solution	600 mg/L	Suspension test	5–30 min	>3 #	[79]
		500 mg/L		5 min, 10–30 min	2–3, >3 #
		400 mg/L		5–10 min, 15–30 min	2–3, >3 #
		300 mg/L		5–30 min	1–2
Bleach (NaOCl)	Disinfection solution	10%	Suspension test	1 min, 5 min	≥3.25	[25]
Household Bleach	Disinfection solution	1:49 (~150 ppm)	Suspension test	5 min, 10 min, 30 min	>4.8	[7]
		1:99 (~75 ppm)	Suspension test	5 min, 10 min, 30 min	>4.8
Sodium hypochlorite and hypochlorous acid	Disinfection solution	0.002% and 0.013%	Suspension test	1 min, 5 min	2.3, 3.75	[25]
Dilutable cleaner (Sodium hypochlorite)	Disinfection solution	0.14% w/w	Suspension test	30 s	≥5.1	[59]
		0.32% w/w	Suspension test (with organic matrix)	5 min	≥5.1
Chlorine dioxide (ClO2)	Disinfection solution	100 ppm	Carrier test on stainless steel (with organic matrix)	30 s, 1 min, 5 min, 10 min	<1.15	[30]
		500 ppm		30 s, 1 min	2.07, 2.53
				5 min	>4 **
				10 min	>4 *
	Wipe	100 ppm		0 s drying post-wiping	2.78 ***
		500 ppm			4.27 ***
Cleverin a	Disinfection solution	80 ppm	Suspension test	10 s–3 min	>4	[78]
		24 ppm		10 s–3 min	>4
		8 ppm		10 s–3 min	3–4
		0.8 ppm		10 s–3 min	1
		80 ppm	Suspension test (with organic matrix)	10 s–3 min	>4
		24 ppm		10 s–3 min	3–4 a
		8 ppm		10 s–3 min	2–3
		0.8 ppm		10 s–3 min	1
Chlorine dioxide b	Disinfection solution	80 ppm	Suspension test	10 s–3 min	>4
		8 ppm		10 s–3 min	>4
		80 ppm	Suspension test (with organic matrix)	10 s–3 min	>4
		8 ppm		10 s–3 min	~2

^a Cleverin (Taiko Pharmaceutical Co., Ltd., Osaka, Japan) is a mixture of 500 ppm ClO₂, 17,900 ppm sodium chlorite, 3300 ppm decaglycerol monolaurate, and 80 ppm silicone. When the viruses were treated with 24 ppm ClO₂ in the presence of 1.0% FBS (fetal bovine serum), the viral titer was decreased by about 4 log₁₀ TCID₅₀ even in 10 s. ^b Pure ClO₂: ClO₂ gas is dissolved in ultrapure water. * No viable virus remained. ** No detectable virus remained on the carrier surface in TCID₅₀ assays; however, one of nine biological replicates (i.e., a single carrier from only one of three independent experiments) showed CPE in safety tests at the 5 min mark. *** Considerably high amounts of viable virus were recovered from both test (0 s, 30 s, 60 s, 5 min drying post-wiping) and transfer carriers, indicating that transferring an infectious material from one surface to another via wiping can occur. ^# Below the detection limit.