The packing group of a Class 8 material is indicated in Column 5 of the Sec. 172.101 Table. When the Sec. 172.101 Table provides more than one packing group for a Class 8 material, the packing group must be determined using data obtained from tests conducted in accordance with the OECD Guideline for the Testing of Chemicals, Number 435, ``In Vitro Membrane Barrier Test Method for Skin Corrosion'' (IBR, see Sec. 171.7 of this subchapter) or Number 404, ``Acute Dermal Irritation/Corrosion'' (IBR, see Sec. 171.7 of this subchapter). A material that is determined not to be corrosive in accordance with OECD Guideline for the Testing of Chemicals, Number 430, ``In Vitro Skin Corrosion: Transcutaneous Electrical Resistance Test (TER)'' (IBR, see Sec. 171.7 of this subchapter) or Number 431, ``In Vitro Skin Corrosion: Human Skin Model Test'' (IBR, see Sec. 171.7 of this subchapter) may be considered not to be corrosive to human skin for the purposes of this subchapter without further testing. However, a material determined to be corrosive in accordance with Number 430 or Number 431 must be further tested using Number 435 or Number 404. The packing group assignment using data obtained from tests conducted in accordance with OECD Guideline Number 404 or Number 435 must be as follows:
(a) Packing Group I. Materials that cause full thickness destruction of intact skin tissue within an observation period of up to 60 minutes starting after the exposure time of three minutes or less.
(b) Packing Group II. Materials other than those meeting Packing Group I criteria 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 three minutes but not more than 60 minutes.
(c) Packing Group III. Materials, other than those meeting Packing Group I or II criteria--
(1) 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
(2) That do not cause full thickness destruction of intact skin tissue but exhibit a corrosion on either steel or aluminum surfaces exceeding 6.25 mm (0.25 inch) a year at a test temperature of 55 C (130 F) when tested on both materials. The corrosion may be determined in accordance with the UN Manual of Tests and Criteria (IBR, see Sec. 171.7 of this subchapter) or other equivalent test methods.
Note to Sec. 173.137: When an initial test on either a steel or aluminum surface indicates the material being tested is corrosive, the follow up test on the other surface is not required. [Amdt. 173-224, 55 FR 52634, Dec. 21, 1990, as amended at 56 FR 66270, Dec. 20, 1991; Amdt. 173-241, 59 FR 67508, Dec. 29, 1994; Amdt. 173-261, 62 FR 24733, May 6, 1997; 68 FR 75744, Dec. 31, 2003; 69 FR 76155, Dec. 20, 2004; 71 FR 78631, Dec. 29, 2006; 74 FR 2257, Jan. 14, 2009; 76 FR 3372, Jan. 19, 2011]