How are canvas tents made to be fire retardant?

Question

While reading through this question about adding a stove jack to a canvas tent originally lacking one, I wondered about the feasibility of making an existing canvas tent fire retardant. Is it simply a matter of adding an additional material or chemical layer to the canvas, or is the process of making the canvas fire-retardant a component of the canvas-making process itself?

For example, is it possible to send a non-fire-retardant canvas tent back to the manufacturer to be made fire retardant, or is it going to be that the customer would need to purchase another tent that is fire-retardant from the start?

In general, how are canvas tents made to be fire retardant?

Answer 1

They are treated with chemicals to be fire retardent.

Fire retardant canvas tarps are treated with substances that lessen flammability. They are not exactly resistant to flames. When fire comes in contact with these tarps, they can delay or stop its spread. Fire retardant canvas tarps are nature friendly. They produce less waste material because they are made of natural fibers.

Source

So what are chemically treated fire retardant fabrics? Well, they are fabrics that have been coated with a fire resistant chemical.

Today, there are more than 175 different types of flame retardants, according to the International Association of Certified Home Inspectors (InterNACHI). These types of chemicals are divided into classes including: brominated, chlorinated, phosphorus-containing, nitrogen-containing, and inorganic flame retardants. Flame retardant chemicals are also known as PBDE’s or polybrominated diphenyl ethers.

Source

Its possible to buy sprays to treat canvas, but from what I can see its not exactly recommended as compared to buying pretreated canvas. It adds both weight and cost to a tent.