A woman died on Tuesday in the eastern city of Al-Marj after applying henna on her hands, health authorities have announced.
Spokesperson of Al-Marj Hospital Mabrokh Saleh said Hanya Othman, 35, was admitted to hospital in critical condition after using henna, but she died shortly after admission.
Mabrookh added that the death toll of henna application deaths have risen to 42 since the registration of the first case in 2011.
"I call on all concerned authorities to reveal the real reason behind these deaths in a scientific way," she said.
Initial tests have shown a high concentration of toxic substance in the henna being used in the market there.
Henna application is a traditional custom in Libya especially during wedding ceremonies.