What Does MSHA Approved SOOW Portable Cord Mean? | The Mine-Safe Cable Guide

Understanding MSHA Approved SOOW Cords

If you are purchasing materials for a sand and gravel quarry, a rock crushing plant, or a heavy underground tunneling operation, your project submittals will likely demand "MSHA-approved wire".

At the same time, your field crew is probably asking for a few reels of standard SOOW portable cord to run temporary lighting strings, conveyor pull-switches, and heavy-duty power tools.

This raises a massive question at the supply counter: What does an MSHA approved SOOW portable cord actually mean? And are all SOOW cords automatically compliant?

Let’s look at the jobsite realities, decode the compliance terms, and make sure your materials pass a field audit.

The Short Answer: What Does the MSHA Stamp Mean on SOOW

To put it simply: An MSHA stamp means the SOOW cord has been structurally engineered and chemically formulated to withstand severe physical abuse and completely self-extinguish if exposed to a catastrophic fire.

SOOW is a broad industry classification for any 600-volt heavy-duty service cord built with oil-resistant rubber insulation and an oil/weather-resistant outer jacket. However, to legally take that SOOW cord onto a regulated mine site, the manufacturer must have submitted that specific jacket compound to the Mine Safety and Health Administration (MSHA) for intense flame-resistance testing.

When you buy SOOW from Wire America, our premium lines feature a specially formulated, vulcanized Chlorinated Polyethylene (CPE) rubber jacket. This compound passes federal flame tests, meaning our SOOW stock is both a high-performance commercial cord and a fully compliant mine-rated wire.

What Does MSHA Actually Test on a SOOW Cord?

In an underground mining or tunneling environment, an electrical fire is the absolute nightmare scenario. Because portable cords are dragged over sharp rocks, pinched under heavy machinery tracks, and exposed to continuous moisture, they face severe physical punishment.

If a cheap plastic or standard PVC cord gets nicked and shorts out, it will ignite and continue to burn, feeding the fire along the cable run and filling the air with toxic smoke.

When MSHA evaluates an SOOW cord under 30 CFR Part 7, Subpart K, they test its ability to survive an open-flame breakdown:

• The Burn Test: They blast the rubber jacket with an intense, high-temperature burner flame.

• The Self-Extinguishing Threshold: Once the flame source is removed, the SOOW jacket must completely self-extinguish within a strict timeframe and cannot allow the fire to travel up the cord.

The Checklist: How to Verify Your Cord is Mine-Safe

When a federal safety officer or project inspector conducts a site audit, they aren't going to look at your receipt—they are going to look directly at the text printed on the wire. To make sure your cable passes inspection, look for these stamps molded into the rubber outer skin:

1. The Core Specs: The gauge size, conductor count, and 600V rating.

2. The MSHA Number: A permanent, stamped code string directly on the jacket (for example: MSHA No. 07-KA-XXXX).

How Wire America Supplies MSHA Approved SOOW Cords

At Wire America, we don't believe in forcing you into buying massive master reels that leave you with hundreds of feet of expensive, unusable scrap material. We supply premium MSHA-accepted SOOW Portable Cords cut straight to the exact foot. You buy only what your layout demands—keeping your project lean, safe, and fully code-compliant.

Need to verify the MSHA specifications or select the right conductor layout for an upcoming project? Connect directly with our sales team for fast, accurate support.

Call us today at (833) 268-8644 or email: sales@wireamerica.com  for custom quote support.

SHOP OUR MSHA APPROVED SOOW PORTABLE CORDS HERE>>

At Wire America, we believe in genuine conversation. You'll always talk with real people who understand that every project requires careful product selection. We supply several different types of Flexible Portable Cords such as SOOW, SJOOW, SEOOW, SJEOOW, STOW, Type W Cable, and Generator Cables. We're here to ensure you feel educated, confident, and great about your final purchase. Feel free to give us a call to discuss your project! You can reach us at: 833-268-8644 or email sales@wireamerica.com

⚠️ Important Disclaimer: Safety and Compliance

Wire America provides this information as a guide only. Electrical installations must strictly adhere to the National Electrical Code (NEC) and all state, local, and jurisdictional requirements, which vary widely. Always consult a licensed electrician, electrical engineer, or the local inspecting authority before purchasing material or starting any electrical project. Wire America assumes no liability for the installation, use, or interpretation of these guides.