At which stage of fire would you expect high smoke production and difficulty breathing?

In the context of fire development, the freeburn stage is characterized by an active fire that produces significant heat and extensive smoke. During this phase, the fire is fully developed, and combustion is well underway. The high levels of smoke created can contain various harmful gases and particulate matter, which can severely impair visibility and create a dangerous atmosphere that makes breathing very difficult.

Within this stage, flames and smoke can spread rapidly, and the rate of oxygen consumption increases, further contributing to the hazardous conditions present. Individuals exposed to the environment during this stage may experience acute respiratory distress due to the inhalation of smoke and toxic byproducts of combustion.

In contrast, the incipient stage refers to the initial phase of fire where conditions are still developing and may not pose immediate danger in terms of smoke or breathing difficulty. The extinguished stage implies that there is no active combustion happening, and while residual smoke may remain, the risks associated with high smoke production would not apply. The term 'initial stage' is somewhat vague in this context, as it overlaps with the incipient phase but does not necessarily indicate the presence of the severe smoke and breathing issues characteristic of the freeburn stage.