When a worker is subjected to a potential fall from a height of 6 feet or greater vertically, the employer is required to provide one of the following fall prevention measures:
- Guardrails around a hazard area
- Install safety nets
- Provide a personal fall arrest system
Safety nets, when installed properly, are able to reduce the distance of a fall from a high level, or prevent the fall altogether. Safety nets are gaining more popularity among employers, as they can provide an alternative to guardrails. For more on guardrails, check out Safety Moment: Guardrail Systems. Safety nets eliminate the need to provide individual equipment to employees, and, in doing so, eliminates the need to inspect each individual item. This makes safety nets a cost effective solution on larger job sites.
As with any fall protection system, OSHA outlines regulatory specifications for the proper use of safety nets. The following provisions must be made by the employer and regulations complied with when a safety net is the chosen form of fall protection.
Safety nets must be installed as close as possible to the working surface, or surface from which the fall may take place, but must not be further than 30 feet below in any case.
When safety nets are used on bridges, the potential fall must be unobstructed.
Safety nets must be drop-tested on the job site at the following times:
- After installation and prior to first use
- If the net is relocated
- After a major repair
- If the net is left in place, after 6 months
The safety net must extend outward from the outermost projection of the work surface in the following manner:
- The vertical distance from working level to horizontal plane of net will determine the minimum required horizontal distance of outer edge of net from the edge of the working surface
- If the vertical distance is up to 5 feet, the maximum horizontal distance of outer edge of the net from the working surface is 8 feet
- If the vertical distance is between 5 and 10 feet, the maximum horizontal distance of outer edge of the net from the working surface is 10 feet
- If the vertical distance is over 10 feet, the maximum horizontal distance of outer edge of the net from the working surface is 13 feet
The drop-test consists of a 400 lb. sandbag dropped from the highest height that a potential fall might occur, and not from less than 42 inches above that level.
Safety nets must be installed with enough clearance to prevent contact with any other surface or structure under them when subjected to an impact force equal to the weight used in the drop-test.
Once the safety net has been drop-tested and has been shown that it is capable of absorbing an impact force equal to the weight used in the drop-test, the net may be certified for use by the employer or other competent person.
The certification means that the net is compliant with the regulations for impact absorption, as well as sufficient clearance.
The certification record must include:
- Identification of the net to be used and the net installation
- Date at which the net was demonstrated as showing compliance to the impact force standards
- Signature of the individual deeming the net as being in compliance and the certification
The employer must keep the most recent certification available on the job site and readily available for inspection.
Nets must also be inspected at regular intervals, at least once per week, and after any occurrence that might have affected the integrity of the system. Defective nets must never be used, and should be tagged and repaired or removed from service. The net should be inspected at least once yearly for UV related deterioration.
Objects that have fallen into the net, must be removed immediately.
The maximum mesh size must not exceed 6 inches by 6 inches. Mesh crossings must be secured in an effort to reduce possible enlargement of the mesh opening. This must be no larger than 6 inches when measured centre-to-centre.
Each safety net, or section of net, must be equip with a boarder rope for webbing with a minimum breaking strength of 5000 pounds.
Connections between nets must meet the same minimum requirements as any other net components, and must not be spaced more than 6 inches apart.
For more details regarding OSHA standards for safety nets, click here.