Synthetic Web Slings

Synthetic web slings are regulated under the MIOSHA Part 49 Slings. Synthetic web slings must be purchased from a manufacturer who has proof tested the slings. Do not make one from synthetic webbing. Synthetic webbing is usually made from nylon or polyester; choose the correct sling based on each job.


  • A synthetic sling must have a permanently affixed, durable identification, stating the size, grade, rated capacity and reach.
  • Synthetic slings must be inspected daily before using, for signs of wear and stress.
  • Synthetic slings must be thoroughly inspected and the inspection documented at least every 12 months.
  • The sling must be proof-tested by the manufacturer when new, repaired or reconditioned. Proof testing is a non-destructive tension test to verify construction and workmanship.
  • A synthetic sling can only be repaired by the manufacturer.
  • Nylon and polyester slings must not be used at a temperature of 180ºF or greater.
  • Polypropylene slings must not be used at a temperature in excess of 200ºF.
  • Stitching is the only method to be used to attach fittings to webbing and to form eyes.
  • A web sling with aluminum fittings cannot be used when caustics are present.
  • Nylon slings cannot be used when acids are present.
  • Polyester and polypropylene slings cannot be used when caustics are present.

Selection and Maintenance

  • Do not store slings in sunlight.
  • Slings may be laundered but hang dry. Using a drying with significantly reduce their strength.
  • Moisture can damage synthetic slings, store in a dry area.
  • Chemicals may affect synthetic slings. Refer to the manufacturer’s specifications for chemical resistance.

Daily Inspection

Remove slings from service if

  • The identification tag is missing or unreadable.
  • Red warning stitches or other warning devices are visible indicating that the sling has been overloaded and damaged.
  • Broken or worn stitching
  • Excessive abrasive wear
  • Knots in any part of the sling
  • Bleached sling color
  • Holes, tears, cuts and snags.
  • Increased stiffness of the material. Acid or caustic burns.
  • Crushed webbing or imbedded particles.
  • Melted or burned areas.
  • Excessive pitting, corrosion, distortion or cracked metal fittings.
  • Other visible damage that may change the strength of the sling.

Safe Lifting

  • Refer to the manufacturer’s lifting tables for the load reductions when lifting with a multi-leg sling.
  • Avoid kinks, loops or twists in the legs.
  • Lift slowly to avoid shock loading and stressing the sling.Do not pull a sling out from under the load with the load resting on the sling. Block the load up to remove the sling.
  • Do not shorten the sling by any means such as knots or bolts.
  • Slings should not be loaded over the rated load.
  • Make sure the sling is assembled properly before lifting.
  • Make sure the periodic inspections have been done before lifting.
  • The manufacturer should perform all repairs and the manufacturer must proof test all repairs.
  • Consult the manufacturer if slings are used at an angle of less than 30º
  • Do not drop slings if they have metal fittings.
  • Sharp corners on items being lifted should be padded to avoid cutting the sling.