More transparency from Chinese authorities on the handling and storage of hazardous waste could have mitigated, or possibly even prevented, the disaster in Tianjin, a UN expert says.
About 700 tonnes of highly toxic sodium cyanide were at the site devastated by last week's major blasts, which killed at least 114 people, and fears are rising that spreading pollution could cause further suffering.
"The lack of information when needed - information that could have mitigated or perhaps even prevented this disaster - is truly tragic," said Baskut Tuncak, the United Nations Special Rapporteur on human rights and hazardous substances and wastes.
"Moreover, the reported restrictions on public access to health and safety information and freedom of the press in the aftermath are deeply disturbing, particularly to the extent it risks increasing the number of victims of this disaster," he added.
Tuncak called on the Communist government to show complete transparency in the investigation of the chemical disaster in the northern port city.
Clean up efforts have been complicated by heavy rainfall on the remains of the industrial site, with anxiety in the area mounting over the extent of contamination.
Officials have insisted that the city's air and water are safe, but locals have voiced scepticism.
Tuncak said China needed to review whether its existing laws on hazardous waste met international standards, and underscored that all information about such material "must be available and accessible" to the public.
The warehouse owner, Ruihai International Logistics, had a licence to handle dangerous chemicals at the time of the blast, but questions have been raised about its credentials.