No. 522 December 2006 

Blast Area Security: Flyrock Safety
 

Objective 

The NIOSH Office of Mine Safety and Health has 

released communication products about flyrock safety 

in the form of informational brochures, flashcards, 

and toolbox talk materials. Both the mining and construction industries are targeted with these helpful 

communication tools. These new products can be 

used as refresher training for employees and as introductory safety materials for onsite visitors. 

Background 

Every blast is associated with the fragmentation, 

and sometimes the projection, of rocks. Flyrock and 

blast area security dominate blasting-related accidents 

in surface mining. From 1978 to 2004, 311 people 

were killed or injured by flyrock at surface mining 

operations. Poor blast area security was often to 

blame. Flyrock is any debris that lands outside the 

designated blasting area. It can vary in mass from 

marble-sized to car-sized and can be incredibly 

dangerous and potentially fatal. Flyrock can be the 

result of an overloaded blast hole, the presence of 

underground voids, insufficient burden, or an inadequately sized blast area. Proper planning by the 

blaster is necessary prior to a blast to prevent or minimize the occurrence of flyrock. 

Forty percent of blasting injuries and fatalities in 

mining occur when people are within the blast area. 

Since blasted material is expected to fall within the 

blast area, good blast area security is essential to 

ensure the safety of site personnel. Figure 1 illustrates 

the importance of securing the blast area. Prior to a 

blast at a surface limestone mine, an equipment 

operator used his pickup truck to guard a road leading 

to the blast site. During the blast, a stone was projected through the truck’s windshield, killing him. 

Preblast planning is essential for determining blast 

area security since each plan has to be site-specific. 

Following a blast, the blaster should walk the blast 

area to determine if the designated area was large 

enough and to see if changes should be made to the 

next shot to improve site safety. 

Figure 1.—Example of flyrock damage to a vehicle at a worksite. 

Approach 

The products described here were developed for 

use in short safety training sessions such as start-ofshift safety talks at the worksite. The information can 

be presented in 15-minute segments. The training can 
be tailored to any work setting by substituting appropriate examples and by discussing the individual 

teaching points in relation to the worksite. 

Specific lessons include: 

• Toolbox Talks 

◦	 What Is Flyrock? – Defines flyrock and its 

characteristics 

◦	 Recognize Blast Area & Signals: Explains 

and identifies the different warnings and signals used in blast areas 

◦	 Clear the Blast Area: Identifies the blast 

area and clearing procedures 

◦	 Protect Yourself: Explains how to prepare 

oneself for each unique blast 

• Visitor’s Hazard Alert: This pamphlet was 

made especially for patrons visiting a blast 

area. It explains how the blasting will be done 

at that particular mine and what signals to 

listen for. 

•	 Worker’s Hazard Alert: This brochure is more 

detailed than the simplified visitor’s pamphlet. 

It explains flyrock in detail, how to protect oneself from it, and what a typical shot scene is 

like, and gives other reminders to think about 

while on location. 

The lessons are in multiple communication formats and informational pamphlets. There are separate 

units focusing on the same topics (Figure 2). The 

pamphlet and flashcards are color-coded into matching sets that relate to the same lesson. This information can be tailored to multiple audiences, including 

both mining and construction. 

Figure 2.—NIOSH communication products on flyrock safety. 

For More Information 

The Blast Area Security–Flyrock Safety communication products are available at: www.cdc.gov/ 

niosh/mining/pubs. For additional information on 

flyrock safety, contact Marcia L. Harris, NIOSH 

Pittsburgh Research Laboratory, P.O. Box 18070, 

Pittsburgh, PA 15236–0070; phone: (412) 386–5780; 

e-mail: MHarris@cdc.gov. 

To receive other information about occupational 

safety and health topics, call 1–800–35–NIOSH 

(1–800–356–4674), or visit the NIOSH Web site at 

www.cdc.gov/niosh 

Mention of any company name or product does not 

constitute endorsement by the National Institute for 

Occupational Safety and Health. 

DHHS (NIOSH) Publication No. 2007–112