S2 E5 Warehouse Safety By Design: NFPA 13 Classification of Commodities

Greetings everyone and welcome to Mighty Line Minute! Today we're continuing our series on siting a warehouse. So, what are the things that we need to look at? We've covered those after the last few episodes.

Today we'll be getting into the issue of commodity classification and why that's important. Stay tuned!

In recent Mighty Line Minute podcasts, we've discussed the process of siting a new warehouse. We covered environmental factors, logistics, transportation, utilities, and even MFL firewalls. And we discussed specific containment and drainage considerations for hazardous material storage. Today, we'll be covering classification of commodities, a necessary and essential step in the design of today's modern warehouse.

And I will challenge you to listen to this entire podcast, as it may be very confusing. Otherwise, you will need to have that person or team, who is designing or siting your warehouse, listen and pay attention to what's ahead! 

NFPA 13 classifies commodities for storage. The purpose is to determine required fire protection systems, as well as identifying necessary building design features. In other words, commodity classification correlates combustibility and fire load of stored materials with the protection schemes and the building design. NFPA 13 divides commodities into Classes I through IV, with three groups of plastics referred to as A, B, and C.

Class I commodities are considered the least combustible, and include non-combustible products stored on wood pallets, or with single-layer corrugated cartons. Examples include: canned goods, metal tools, cement, glass, etc. Class II commodities are similar to Class I, but with more combustible packaging.

Think about products in multi-layer corrugated cartons. Class III commodities may contain combustible materials, such as wood, paper, natural fibers, though with limited plastics. Examples include: wood furniture, or paper bags. Class IV commodities are more combustible than Class III, due to increased plastic content.

They may include products mixed with plastics, or products including plastic packaging. Separately, if plastic pallets are intended to be used or considered, a deeper evaluation within NFPA 13 is necessary. This is due to their potential impact to overall fire load, exposure, and protection schemes.

Plastic commodities represent a higher fire risk than common Class I through Class IV commodities. 

Group A plastics are considered the most hazardous of the plastics group, and are beyond what's considered a Class IV commodity. They include ABS, polypropylene, polystyrene, polycarbonate, polyethylene, acrylic, nitrile rubber, and highly-plasticized PVC. Group B plastics are considered moderately combustible, such as silicone rubber.

They are also considered a Class IV commodity. Group C plastics are the least combustible of the group, and include fluorplastics, melamine, and PVC with less than 20 percent plasticizer. They are considered a Class III commodity. Some materials, like rubber tires or rolled paper storage, require additional and unique protection strategies further explained within NFPA 13.

So, what about flammable and combustible liquids? NFPA 30's Flammable and Combustible Liquids Code covers materials such as motor oil, engine cleaners, lighter fluid, Tiki Torch® fuel, solvent-based paints or stains, and products containing acetone, isopropanol, MEK, mineral spirits, naphtha, toluene, and many others.

Flammable and combustible liquids are considered by NFPA 30 to be "Ignitable Liquids." They are presently classified by their flashpoints and boiling points, rather than their heats of combustion. Lower flashpoints indicate higher flammability. Relative to closed-cup flashpoints, NFPA's categories, of which there are five, include Class IA and IB flammable liquids, where both have flashpoints <73 degrees F. Class IC flammable liquids with flashpoints between 73 to <100 degrees F. Class II combustible liquids, which are 100 to <140 degrees F. Class IIIA combustible liquids, which are from 140 to <200 degrees F. And finally, Class IIIB combustible liquids, which have flashpoints ≥200 degrees Fahrenheit.

There are further nuances between NFPA 30, OSHA, and GHS, so let's add more confusion. Both the Global Harmonization System and OSHA simply refer to "flammable liquids", as they have dropped the term "combustible liquids."

Flammable liquids under GHS and OSHA are subdivided into four categories: Flammables 1, 2, 3, and 4. Flammables 1 and 2 have flashpoints <23 degrees centigrade. Flammable 3 has a flashpoint between 23 and 60 degrees centigrade, with Flammable 4 having a flashpoint >60 degrees centigrade, and ≤93 degrees centigrade.

FM Global's Data Sheet 7-29 expands upon NFPA's "Ignitable Liquids" definition by including certain water-based coatings, inks, adhesives, emulsions, and vegetable-based biofuels that may actually support combustion.

Moving on, NFPA 30B is the Code for the Manufacture and Storage of Aerosol Products.

This code covers aerosol spray insecticides, cleaners, lubricants, and paints that incorporate the use of flammable propellants. Commodities such as these are ranked by their relative heats of combustion. Generally speaking, Level 1 is the least flammable, Level 2 is moderately flammable, and a Level 3 aerosol product is the most flammable, based upon its contents and the mixture's higher aggregate heat of combustion.

For oxidizers and corrosives, you'll need to spend time reviewing the Hazardous Materials Code, NFPA 400. For example, common oxidizers such as calcium hypochlorite and sodium hypochlorite can react dangerously and release toxic gases. Fire and building codes describe how best to store such materials apart from flammable or ignitable liquids.

Corrosives such as muriatic acid and organic peroxides present unique fire risks. So pay attention to commodities such as, hair bleach and dyes, fast-curing adhesives that are catalysts, high-strength dental whitening products, MEK peroxide used in boat building and automotive applications, and other compounds used in plastics, rubber, or foam manufacturing.

And what about fireworks storage? Follow NFPA 1124 and Building and Life Safety Codes that apply to get the scoop on these commodities and their required storage and protection schemes. 

Once you've studied and aligned yourself with greater knowledge on commodity classifications, only then you will be able to determine the essential building design, construction, and protection schemes required.

In other words, code compliance.

So remember, commodity classification remains just one step in the sequence of many, that is necessary to determine how to properly site, design, and construct a warehouse in today's operating environment. Hopefully, through this podcast today and our earlier ones, you'll have gained more insight into how to achieve warehouse safety by design.

Be sure to go to MightyLineTape.com to learn more about safety excellence, and in particular, how to 5S your facility, whether it be an industrial, manufacturing or warehousing operation .. and take time to learn, the codes, standards, and means to make yourself a better operation.

So thanks everyone for taking time with us today on Mighty Line Minute! 

Take care.