A note on bleach v. HOCl

There is a popular misconception that because bleach (NaOCl) and hypochlorous acid (HOCl) are superficially similar molecules, both of which contain chlorine and oxygen, they are assumed to have similar properties. This not the case.

Bleach is widely used to disinfect, and the most common form used is sodium hypochlorite, which is usually found in household products at a concentration of around 5 to 10% in a highly alkaline solution. It is highly irritating to the eyes, skin and lungs, and inhalation over long periods could be carcinogenic. It can also leave a residue and is corrosive to some metals.

In contrast, HOCl has a temporary, mild chlorine smell that dissipates quickly; it is hypoallergenic and completely safe and, most importantly, is more reactive with organic matter.

The difference between HOCl and household bleach

Sodium hypochlorite is strongly alkaline and highly corrosive.

Whilst HOCl  is considerably less corrosive, depending on the manufacturing process residual salts from electrolysis may cause some corrosion.

Is NaDCC safer than bleach?

Accidental exposure

“NaDCC solutions resulted in lower airborne chlorine exposures and fewer detections at or above the measuring instrument's limit of detection than bleach solutions.”

NaDCC Disinfectant in Janitorial Cleaning and Comparison to Bleach: Exposure Assessment

Deliberate ingestion

Bleach ingestion is frequently used for suicide which results primarily from caustic effects on upper gastrointestinal tract.

However, when at least 11g of NADCC tablets were ingested deliberately, the resultant respiratory failure was successfully treated by extracorporeal membrane oxygenation (ECMO) and the patient was discharged from hospital after 27 days.

Early ECMO initiation in the emergency department for refractory hypoxemic respiratory failure caused by NaDCC intoxication