Safety is rarely anyone’s favorite topic to cover. However, there’s never a bad time for a quick refresh on some safety signs and signals that could prevent injuries and accidents on site.
To start, let’s go over some construction flag markings that notify crew members and the public of potential ground hazards. These flags are frequently used on heavy/highway, site preparation, bridge, asphalt and concrete paving, airport, and utility projects.
According to the American Public Works Association (APWA) Uniform Color Codes, here is the list of hazard markers that should be used on a job site and what each flag color means:
White: proposed excavation route. This marking can be made with flags, stakes, whiskers, safety skirts, and spray chalk if the area is a paved surface. According to the USA North 811 Excavation Handbook, “Temporary markings should be visible, functional, and considerate to surface aesthetics and the local community.” Contractors should be aware of local ordinances before digging in delineated areas.
Orange: communication, alarm or signal lines, cables, or conduit. Orange signs with black lettering are especially important for our industry. These signs are used to warn drivers of upcoming roadwork. Distracted drivers are one of the biggest hazards road crews face. To get drivers’ attention, it is best to use multiple signals and barricades. Read our previous blog about how to keep roadside crews safe here.
Red: electric power lines, cables, conduit, and lighting cables. Red flag areas pose a significant threat to crew members if not marked properly. Potential electrocution, fires, and explosions can occur in these areas.
Yellow: natural gas, oil, steam, petroleum, gaseous materials. These areas also pose a threat of potential fires and explosions due to the presence of flammable substances. According to OSHA, “If an underground utility is damaged, the utility operator is in the best position to determine the hazards associated with the damage and implement appropriate countermeasures.” Continuing,”OSHA recommends that the excavator notify the utility operator promptly. If the damage results in the release of hazardous gases or liquids, both the utility operator and appropriate emergency response officials should be notified immediately.”
Blue: potable water. The balance small business states that contractors should take steps to avoid erosion and properly discharge water during a dewatering project. For crew safety, it is important to watch for signs of instability in the soil. Warning signs include visible cracks, leaning or curved trees, guardrails and other structures, toe erosion, hummocky slope surface, and changes in the soil moisture.
Green: sewers and drain lines. These warning signs should be clear around manholes to warn passersby and proper PPE should be worn around dangerous contaminants.
Purple: reclaimed water, irrigation, and slurry lines. Always contact your state’s designated “Before You Dig” hotline prior to beginning construction.
Pink: temporary survey markings, unknown/unidentified facilities.
There are a wide variety of hand signals that are important for reducing accidents and near-misses on the job site. Below is a list of hand signals provided by OSHA specifically for heavy machinery operators (rollers, excavators, backhoes, etc.)
Only one person should be giving hand signals for a particular piece of equipment and the signaler and equipment operator should discuss and agree on the hand signals prior to working.
Check out more hand signal basics for earthmoving from Diesel and Iron:
Want to test your hand signal knowledge? Try this Hand Signals For Construction Equipment training quiz.
When putting all of this safety knowledge into action, it is important to do daily toolbox talks to ensure all crew members are on the same page. It is also crucial to document all on-site incidents.
Too many times when accidents happen, companies are caught scrambling for proof that they took the necessary precautions. Without proper documentation, not only are you unable to save yourself from litigation, but you also can’t be sure you’re doing everything in your power to protect your employees.