Class 2, Division 6.2 and Class 7 materials have no packing groups.

• Packing Group I – high danger
• Packing Group II – medium danger
• Packing Group III – Low danger

Packing Group	Flash Point	Initial Boiling Point
I		≤ 35°C (95°F)
II	≤ 23°C (73°F)	> 35°C (95°F)
III	≥ 23°C (73°F) but ≤ 60.5°C (141°F)	> 35°C (95°F)

Division 4.1 Packing Groups

Packing Group I – Pyrophoric liquids and solids.

Packing Group II – Positive test result when tested with a 25mm cube size sample at 140°C.

Packing Group III –      If one of the following is true:

• A positive test is obtained in a test using a 100mm sample cube at 140°C and a negative test result is obtained in a test using a 25mm sample cube at 140°C and the substance is transported in packagings with a volume of more than 3 cubic meters
• A positive test result is obtained in a test using a 100mm sample cube at 120°C and a negative test result is obtained in a test using a 25mm sample cube at 140°C and the substance is transported in packagings with a volume of more than 450 liters
• A positive test result is obtained in a test using a 100mm sample cube at 100°C and a negative test result is obtained in a test using a 25mm sample cube at 140°C and the substance is transported in packagings with a volume of less than 450 liter

Division 4.3 Packing Groups

Packing Group I – Material reacts vigorously with water at ambient temperatures and  demonstrates a tendency for the gas produced to ignitespontaneously,  or which reacts readily with water at ambient temperatures such that the rate of evolution of flammable gasses is equal or greater than 10 liters per kilogram of material over any one minute

Packing Group II –  Material reacts readily with water at ambient temperatures such that the maximum evolution rate of flammable gases is equal to or greater then 20 liters per kilogram of material per hour, and the material does not meet the criteria for PG I

Packing Group III – Material reacts slowly with water at ambient temperatures such that the maximum evolution rate of flammable gases is greater than 1 liter per kilogram of material per hour, and the material does not meet criteria for PG I or II

Division 5.1 Packing Groups (liquids)

Packing Group I –  Any material that spontaneously ignites when mixed with cellulose in a 1:1 ratio or any material that exhibits a mean pressure rise time less than the pressure rise time of a 1:1 perchloric acid (50%):cellulose mixture

Packing Group II –  Material that exhibits a mean pressure rise time less than or equal to the pressure rise time of a 1:1 aqueous sodium chlorate solution (40%):cellulose mixture, and does not meet the criteria for PG I

Packing Group III – Material that exhibits a mean pressure rise time less than or equal to the pressure rise time of a 1:1 nitric acid (65%):cellulose mixture, and does not meet the criteria for PG I or II

Division 5.1 Packing Groups (solids)

Packing Group I –  Material that exhibits a mean burning time less than the mean burning time of 3:2 potassium bromate:cellulose mixture

Packing Group II – Material that exhibits a mean burning time less than or equal to the mean burning time of a 2:3 potassium bromate:cellulose mixture and does not meet the criteria for PG I

Packing Group III – Material that exhibits a mean burning time less than or equal to the mean burning time of a 3:7 potassium bromate:cellulose mixture and does not meet the criteria for PG I or II

Division 6.1 Packing Groups

For poisons which are not inhalation hazards:

Packing Group	Oral toxicity LD50 (mg/kg)	Dermal toxicity LD50 (mg/kg)	Inhalation toxicity by dusts and mists LC50 (mg/L)
I	≤ 5	≤ 40	≤ 0.5
II	> 5 but ≤ 50	> 40 but ≤ 200	> 0.5 but ≤ 2
III	solids: > 50 but ≤ 200; liquids: > 50 but ≤ 500	> 200 but ≤ 1000	> 2 but ≤ 10

Class 8 Packing Groups

Packing Group I – Material that causes full thickness destruction of intact skin tissue within 60 minutes, starting after an exposure time of three minutes or less.

Packing Group II – Material that causes full thickness destruction of intact skin tissue within 14 days starting after an exposure time of more than three minutes but not more than 60 minutes.

Packing Group III – Material that cause full thickness destruction of intact skin tissue within an observation period of up to 14 days starting after the exposure time of more than 60 minutes but not more than 4 hours

          Or

Material that do not cause full thickness destruction of intact skin tissue but exhibit a corrosion rate on steel or aluminum surfaces exceeding 6.25 mm (0.25 inch) a year at a test temperature of 55°C (130°F). For the purpose of testing steel P3 (ISO 9328-1) or a similar type, and for testing aluminum, non-clad types 7075-T6 or AZ5GU-T6 should be used. An acceptable test is described in ASTM G 31-72