The incident occurred at Phule Nagar slums in Filterpada, Powai, at 8pm on Thursday. Police said Gawhane used to have frequent fights with Ayush's parents over trivial issues.
Police said Gawhane was infuriated as Ayush always played outside her house. After arguing with Ayush's mother on Wednesday night over this, Asha took a bottle of floor cleaning chemical from her house and flung it at Ayush who was playing outside.
Ayush's father came running on hearing his cries. "The child was taken to hospital but his skin had turned black by then. We then arrested Gawhane who had taken shelter at a neighbour's place. We have recovered two bottles of carbolic acid from her possession. Samples have been sent for a chemical analysis," Sawant said.
Gawhane, who works as a sweeper at a hospital, used to have frequent fights with Ayush's parents. "The accused was at loggerheads with her neighbours. She used to argue over minor issues such as children making noise while playing and so on. She does not have any criminal record," Sawant said.
The police have registered a case under sections 326 of the Indian Penal Code for voluntarily causing grievous hurt by dangerous weapons or means.