政策法规现行有效美国危险品合规

§ 173.121 Class 3—Assignment of packing group.

效力	法规类型	发布日期	生效日期	发文机构
现行有效	部门规章	2026-08-07	2026-09-08	Code of Federal Regulations (CFR) - Transportation (Title 49)

发布08-07

生效09-08

摘要总结AI 辅助解读

该条款规定了美国49 CFR下第3类易燃液体（Class 3）包装组别（Packing Group, PG）的判定标准。核心依据为闭杯闪点与初沸点：PG I（闪点≤35°C且初沸点≤35°C）、PG II（闪点35°C）、PG III（闪点≥23°C且≤60°C且初沸点>35°C）。对于高粘度物质，若满足溶剂分离测试、无次要危险性（6.1/8类）及特定粘度/闪点组合条件，可从PG II降级至PG III。建议核实产品理化数据以准确分类。

(a)(1) The packing group of a Class 3 material is as assigned in column 5 of the § 172.101 Table. When the § 172.101 Table provides more than one packing group for a hazardous material, the packing group must be determined by applying the following criteria:

Packing group Flash point (closed-cup) Initial boiling point I ≤35 °C (95 °F) II <23 °C (73 °F) >35 °C (95 °F) III ≥23 °C, ≤60 °C (≥73 °F, ≤140 °F) >35 °C (95 °F)

- (2) The initial boiling point of a Class 3 material may be determined by using one of the following test methods:

(i) Standard Test Method for Distillation of Petroleum Products at Atmospheric Pressure (ASTM D 86) (IBR; see § 171.7 of this subchapter);

- (ii) Standard Test Method for Distillation Range of Volatile Organic Liquids (ASTM D 1078) (IBR; see § 171.7 of this subchapter);

- (iii) Petroleum Products—Determination of Distillation Characteristics at Atmospheric Pressure (ISO 3405) (IBR; see § 171.7 of this subchapter);

- (iv) Petroleum Products—Determination of Boiling Range Distribution—Gas Chromatography Method (ISO 3924) (IBR; see § 171.7 of this subchapter);

(v) Volatile Organic Liquids—Determination of Boiling Range of Organic Solvents Used as Raw Materials (ISO 4626) (IBR; see § 171.7 of this subchapter); or

- (vi) Petroleum products containing known flammable gases—Standard Test Method for Determination of Light Hydrocarbons in Stabilized Crude Oils by Gas Chromatography (ASTM D7900) (IBR; see § 171.7 of this subchapter) where the initial boiling point is the temperature at which 0.5 weight percent is eluted when determining the boiling range distribution.

(b) Criteria for inclusion of viscous Class 3 materials in Packing Group III. (1) Viscous Class 3 materials in Packing Group II with a flash point of less than 23 °C (73 °F) may be grouped in Packing Group III provided that—
(i) Less than 3 percent of the clear solvent layer separates in the solvent separation test;

- (ii) The mixture or any separated solvent does not contain any substances with a primary or a subsidiary risk of Division 6.1 or Class 8;

- (iii) The capacity of the packaging is not more than 450 L (119 gallons); except that for transportation by passenger aircraft, the capacity of the packaging is not more than 30 L (7.9 gallons) and for transportation by cargo aircraft, the capacity of the packaging is not more than 100 L (26.3 gallons); and

- (iv) The viscosity 1 and flash point are in accordance with the following table:

1 Viscosity determination: Where the substance concerned is non-Newtonian, or where a flow-cup method of viscosity determination is otherwise unsuitable, a variable shear-rate viscometer shall be used to determine the dynamic viscosity coefficient of the substance, at 23 °C (73.4 °F), at a number of shear rates. The values obtained are plotted against shear rate and then extrapolated to zero shear rate. The dynamic viscosity thus obtained, divided by the density, gives the apparent kinematic viscosity at near-zero shear rate.

Kinematic viscosity (extrapolated) ν (at near-zero shear rate) mm2/s at 23 °C (73.4 °F) Flow-time t in seconds Jet diameter in mm Flash point c.c. 20 < ν ≤ 80 20 < t ≤ 60 4 above 17 °C (62.6 °F). 80 < ν ≤ 135 60 < t ≤ 100 4 above 10 °C (50 °F). 135 < ν ≤ 220 20 < t ≤ 32 6 above 5 °C (41 °F). 220 < ν ≤ 300 32 < t ≤ 44 6 above −1 °C (31.2 °F). 300 < ν ≤ 700 44 < t ≤ 100 6 above −5 °C (23 °F). 700 < ν 100 < t 6 No limit.

- (2) The methods by which the tests referred to in paragraph (b)(1) of this section shall be performed are as follows:

(i) Viscosity test. The flow time in seconds is determined at 23 °C (73.4 °F) using the ISO standard cup with a 4 mm (0.16 inch) jet as set forth in ISO 2431 (IBR, see § 171.7 of this subchapter). Where the flow time exceeds 100 seconds, a further test is carried out using the ISO standard cup with a 6 mm (0.24 inch) jet.

- (ii) Solvent Separation Test. This test is carried out at 23 °C (73 °F) using a 100.0 mL(3 ounces) measuring cylinder of the stoppered type of approximately 25.0 cm (9.8 inches) total height and of a uniform internal diameter of approximately 30 mm (1.2 inches) over the calibrated section. The sample should be stirred to obtain a uniform consistency, and poured in up to the 100 mL (3 ounces) mark. The stopper should be inserted and the cylinder left standing undisturbed for 24 hours. After 24 hours, the height of the upper separated layer should be measured and the percentage of this layer as compared with the total height of the sample calculated.

[Amdt. 173-224, 55 FR 52634, Dec. 21, 1990]

Editorial Note: For Federal Register citations affecting § 173.121, see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at www.govinfo.gov.