The Chinese government has ordered a nationwide review of workplace safety, after last week’s warehouse explosion that killed at least 114 people and destroyed dozens of buildings in the port city of Tianjin.

The incident was particularly hazardous for first responders, according to news sources. Among the dead: 21 firefighters – a number which could go much higher, because the 70 people still missing after the blast include 64 firefighters, as well as six police officers.

The directive from the country’s Ministry of Industry and Information Technology demanded that government authorities check on companies within their jurisdiction that produce or store hazardous materials, to determine whether or not they comply with safety regulations.

More than 700 tons of sodium cyanide were being stored at the warehouse that exploded – well above the ten tons allowed by safety regulations. Additionally, the facility was closer to residential areas than is allowed under current regulations.

When it comes into contact with water, sodium cyanide can form combustible substances. It can also release hydrogen cyanide gas, a highly toxic chemical asphyxiant that interferes with the body's ability to use oxygen, according to the CDC – something that has raised fears about air quality in the area.

Authorities have also said that they will investigate the potential of criminal charges relating to the incident.

The massive explosions – which generated mushroom-shaped clouds, reportedly followed a fire at the warehouse.

China has had a number of serious industrial accidents in recent years. A fire at a poultry plant in the province of Jilin in 2013 claimed 121 lives. A dust explosion at a metal plant in the province of Jiangsu killed 97 people.