A new World Health Organisation (WHO) review has shown that insecticide lindane could cause cancer in humans.
A specialist panel found sufficient evidence to link the chemical, which is already banned in the European Union and the United States, to a cancer called non-Hodgkin lymphoma.
It is however still used in some developing countries and is an ingredient in some head lice and scabies treatments used in some countries like China, India, the US and Canada.
The International Agency for Research on Cancer (IARC) panel also concluded that other insecticides, DDT and 2,4-D , were "probably carcinogenic to humans" - meaning it's a possible cancer-causing agent.
According to BBC, most uses of DDT have been banned since the 1970s, but the IARC says exposure to DDT still occurs, mainly through diet, as DDT and its breakdown products are highly persistent and can be found in the environment and in animals.
2,4-D, on the other hand, has been widely used to control weeds in agriculture, forestry, and urban and residential settings.
Exposure to 2,4-D can occur during manufacturing and application, and the general population can be exposed through food, water, dust, or residential application, and during spraying.
This is according to IARC.
The group's head, Dr Kurt Straif said the evidence on lindane and cancer was largely based on studies among agricultural workers that showed a consistent, approximately 50% increase in risk, with higher risks in heavily exposed agricultural workers.