Should I worry about closet mold or use bleach myself?« Back to Previous Page

Given your description and the scratchy throat, this is a situation that warrants professional inspection, not a DIY bleach attempt. The appearance after a humid period on an external wall strongly suggests a condensation or moisture intrusion issue, which is the root cause that must be addressed.

In Dubai's climate, that external wall is likely a "cold bridge," where the intense outdoor heat meets your AC-cooled interior, causing persistent condensation inside the wall cavity. Bleach only removes surface discolouration on non-porous materials; it cannot penetrate porous surfaces like drywall or address hidden mould growth inside the wall. More critically, it poses respiratory risks in an enclosed space and can actually feed certain mould types by adding moisture.

The urgency is moderate. Isolate the area by keeping the closet door closed until it can be assessed. A professional inspection will use a moisture meter to identify the exact source of water and may recommend thermal imaging to see the extent of the condensation problem behind the wall. The goal is to diagnose and fix the moisture issue first; only then can the mould be properly remediated. For health verification, a lab analysis can identify the species, which helps assess potential risk, especially since "black mould" is often used to describe many different types.