Concentrations above 5ppm in air can cause serious problems. You might want to look at this paper, if only to see that, commercially, HCl solutions have another name which can be misleading, Muriatic Acid. What happens if muriatic acid fumes are inhaled?
Answer: A palapa is a thatched-roof, open-sided structure (see palapa photo). The material to cover the roof of a palapa typically consists of dried and woven palm-tree leaves. A palapa is sometimes referred to as a grass or tiki hut.
Palau is a beautiful tropical paradise, and one of the true unspoiled destinations on the planet. Most of the 100-plus islands are small low-lying coral islands, ringed by barrier reefs. The exception is mountainous Babulthuap, volcanic in origin.