• Per 49 CFR 172.302(b), except as otherwise provided in the regulations, markings on a bulk packaging must:
  • Have a width of at least 6.0 mm (0.24 in) and a height of at least 100 mm (3.9 in) for rail cars.
  • Have a width of at least 4.0 mm 90.16 in) and a height of at least 25 mm (1 in) for portable tanks with a capacity of less than 3,785 L (1,000 gal) and intermediate bulk containers (IBCs).
  • Have a width of at least 6.0mm (0.24 in) and a height of at least 50 mm (2.0 in) for cargo tanks and other bulk packagings.
  • Note: a marking on a bulk packaging includes – but is not limited to – the identification number.  For example, in some instances the proper shipping name is required as a marking on the package as well.
• Per 49 CFR 172.332(b), if displayed on an orange panel the identification number must be at least 100 mm high of black helvetica medium numerals.
• Per 49 CFR 172.332(c), if displayed on a placard the identification number must be 88 mm high of black alpine gothic or alternate gothic #3 numerals.
• Per 49 CFR 172.336(b), if displayed on a white square-on-point the identification number must of the same dimensions as it is displayed on the placard at §172.332(c).

• 49 CFR 172.325(c): “HOT” must be in black letters having a height of at least 50 mm (2.0 in).
• 49 CFR 172.326(a): portable tank marked on two opposing sides with proper shipping name with a minimum height of 65 mm (2.5 in).  However, portable tank of with a capacity of less than 3,00 L (792.52 gal) may be reduced to a marking size of not less than 12 mm (0.47 in).
• 49 CFR 172.328(b): cargo tank transporting a Class 2 Compressed Gas – except certain nurse tanks – must be marked in lettering no less than 50 mm (2.0 in).
• 49 CFR 172.328(c): each MC 330 and MC 331 cargo tank marked with “QT” or “NQT” in letters no less than 50 mm (2.0 in) in height.
• 49 CFR 172.328(d): after October 3, 2005, “Emergency Shutoff” (if and where applicable) in letters at least 0.75 in in height.
• 49 CFR 172.330(a)(2): shipping name and identification number marked on multi-unit tank car tank in letters and numerals no less than 50 mm (2.0 in) high.

Conclusion:

That seemed to answer his questions! Here is another example of where compliance isn’t just about avoiding fines, it’s about your business.  If you are in the business of providing products or services to shippers and carriers of hazardous materials you need to know the regulations just as well as your customers.  My USDOT/PHMSA HazMat Employee training can help you to do that!