Khesari or Lathyrus odoratus is a hardy pulse crop that can grow in both drought as well as waterlogged conditions. The grain has traces of a toxin called beta-amino-propio-nitrile, which, when ingested, causes limb paralysis and bone deformity — the result of a neurological disorder called lathyrism. In 2010, the Planning Commission had asked the ICMR to conduct an epidemiological study of the dal in Chhattisgarh, where its cultivation is the highest.

In 2015 the Scientific Panel citing a report by the Indian Institute of Toxicological Research which had said that lifting the ban on khesari dal would be “improper” since its consumption is “not safe” had called for more scientific efforts to make it safe.

Further, a study conducted by the National Institute of Nutrition, Hyderabad, on goats, also recorded abnormal effect on the animals which were given the toxin reportedly produced by khesari grains.

However, despite the more than 50 year old ban and medical concerns, the pulse is still available across markets, and is used to adulterate other pulses.  With the price of arhar dal shooting up to Rs. 200 per kilogram, retailers have started mixing khesari dal as it looks similar. This also ensured reduction in the price, thereby making it accessible to the economically weaker sections of society.