As green seaweed presence dramatically multiplies and intensifies on coasts, there are many other “annoying” algae as well that strands on the seashore.
When they decompose (anaerobic fermentation), these organic matters release an easily recognizable gas (at very low concentration) with a rotten egg smell that disappears at higher concentrations. This gas is hydrogen sulfide – also known as sulfurated hydrogen or sour gas.
Hydrogen sulfide is considered as a toxic and hazardous gas. Prolonged inhalation of this gas may cause degeneration of the olfactory nerve (making the gas undetectable through smell), lead to loss of consciousness (even at low concentration) or can even lead to death…
Using a portable H2S gas detector (single-gas or multigas) remain the safest way to get alerted on the presence of hydrogen sulfide in the atmosphere. This device will moreover clearly indicate the instant concentration as well as the time-weighted average value (TWA) and the exposure limit value (ELV). When a limit is exceeded, the gas detector will alert through an audiovisual signal up to 95 dBA.
In case of an H2S dangerous concentration alert, operators need to wear respiratory protective masks equipped with B filter cartridges (preferably B2). It is also possible to wear a half-mask but as hydrogen sulfide might irritate eyes it would be preferable to wear a full-face respirator for enhanced protection…
So, even on vacation on the beach, stay vigilant …
Have a good swim!