GB/T 20285-2006Toxic classification of fire effluents hazard for materials (English PDF)

3.1 Generating stably smoke from a material

A smoke-generating process in which the mass number of smoke-generating materials remains constant at all times, and the relative proportion of smoke products remains unchanged.

3.2 Concentration of the specimen mass for smoke

A parameter reflecting the relationship between smoke and material mass in a fire scene, specifically the mass of smoke-generating material per unit space, expressed in mg/L.

3.3 Yield of smoke from material

The percentage of the mass of a material entering the space during smoke generation relative to the total mass of the material. It is a parameter reflecting the degree of thermal decomposition or combustion of the material.

3.4 Sufficient yield of smoke

The material's maximum or near-maximum smoke generation rate.

3.5 Flow of fire effluents

A parameter describing the flow performance of flue gas, specifically the volume of flue gas flowing per unit time, expressed in L/min.

3.6 Rate of generating smoke from a material

The mass of material undergoing thermal decomposition and combustion per unit time, in mg/min.

3.7 Inhalation exposure

This refers to a type of injury caused to humans or animals in polluted environments, primarily through respiration, but also including some sensory contact with toxins.

3.8 Acute inhalation exposure

This refers to inhalation exposure with a relatively short time (generally within 30 min).

3.9 End point

A physiological response point in laboratory animals, such as loss of escape ability or death.

5.1 Level classification

5.1.1 The toxicity hazard of the smoke generated by the material is divided into three levels. safe level (AQ level), quasi-safe level (ZA level), and dangerous level (WX level). Among them, the AQ level is further divided into AQ1 and AQ2, and the ZA level is further divided into ZA1, ZA2, and ZA3.

5.1.2 The smoke concentration indicators for different levels of materials are shown in Table 1.

5.2 Test end point for level determination

A group of experimental mice are exposed to toxic fumes generated by the material at its sufficient yield of smoke for 30 min at concentrations specified in Table 1. The following criteria are applied based on the results. If no mice died during the exposure period (including within 1 h after exposure), the material is deemed to be toxic at that concentration level. If no mice died or experienced weight loss after 30 min of exposure, or if their weight decreased but recovered to or exceeded their average weight at the time of the experiment within 3 days, the material was deemed to be irritant at that concentration level. The highest concentration level deemed toxic for both anesthetic and irritant effects shall be defined as the toxic level of fire effluents hazard for the material.

6.1 Equipment composition

The test equipment consists of a ring furnace, a quartz tube, a quartz boat, a flue gas collection and distribution assembly, a mouse rotating cage, an exposure chamber, a mixing control system, a furnace displacement system, an airflow supply system, and a mouse motion recording system, as shown in Figure 1.

6.2 Circular furnace

The annular furnace, as shown in Figure 2, consists of a furnace shell, furnace body, furnace tubes, and electric heating wires. The inner wall of the furnace tubes serves as the heating surface. The inner diameter of the furnace tubes is mm, and the length is mm. The winding and power of the electric heating wires shall meet the requirements of 7.2. […]