Based on Delta Plus's expert guide: the steps for choosing the size, adjusting the straps, positioning the attachment points, pre-use inspection, cleaning and storage of a full body harness.
Choosing the right model is not enough on its own for a fall arrest harness to provide protection: the harness must be correctly adjusted to the user, inspected before every use and stored in suitable conditions. The guide, based on explanations by Delta Plus fall protection expert Cécilia Lemoine and updated in April 2026, sets out these steps in an order that can be applied on site. According to the guide, a harness that is too loose may fail to hold a worker who has lost consciousness, while a harness that is too tight can cause injury and discomfort.
Step-by-step adjustment
- Size: Depending on the model, Delta Plus harnesses come in three sizes: PT (XS–S), GT (S–M–L) and XX (XL–XXL).
- Waist belt: It should sit just above the hip bones without being over-tightened, so that it does not obstruct the chest attachment point. Check that the positioning buckles on the waist belt are level with the projections of the pelvic bone (the iliac bones).
- Leg and shoulder straps: You should be able to slide a hand under the strap, but not a fist.
- Back (dorsal) attachment point: It should be between the shoulder blades; it should not rise as high as the cervical vertebrae, nor sit so low that it changes the fall angle.
- Chest (sternal) attachment point: It should not be too close to the navel, nor so high that it creates a risk of striking the chin.
Pre-use inspection
The guide defines equipment inspection as the first golden rule of fall protection and regards it as the duty of every user. During the inspection:
- Hold the harness by the back attachment point, open out the straps and make the whole harness visible.
- Check the straps for adhesive contamination, cuts, fraying and UV damage.
- Check that the buckles work properly and are free from corrosion.
- On Delta Plus Evolution and Premium harnesses, locate and check the fall indicators.
Partner check, cleaning and storage
The guide's second golden rule is never to work alone with fall protection equipment. In this context, it recommends that a colleague checks, for example, that the straps on the back are not twisted. For care and storage:
- Use mild soap for cleaning and dry the harness in the open air.
- Store the harness in a dry place away from UV light and, if possible, in its original box.
According to the Delta Plus expert, following these good practices gives Delta Plus harnesses a service life of 10 years. This assessment is the manufacturer's own; in every case, the service life, periodic inspection and post-fall withdrawal conditions set out in the product's user instructions must be followed.
A note for OHS teams
Harness adjustment is a skill that is reinforced through training and hands-on checks. In work-at-height training, having users adjust their own harnesses, apply the hand-and-fist test and carry out the partner check together makes it easier to put the guide's steps into practice on site. Recording inspection results and the reasons for withdrawing harnesses from use also provides traceability during audits.
In the Vertex Safety Türkiye catalogue you can browse Delta Plus full body harnesses, including HAR11, HAR22H, HAR24H and HAR42EL, and get support from our technical team on the right model and size for your work.
Frequently asked questions
How tight should the harness straps be?
According to the Delta Plus guide, you should be able to slide a hand under the leg and shoulder straps, but not a fist.
Where should the back attachment ring be?
According to the guide, it should be between the shoulder blades; it should not rise as high as the cervical vertebrae, nor sit so low that it changes the fall angle.
How should the harness be cleaned and stored?
Delta Plus recommends cleaning it with mild soap and drying it in the open air, and storing it in a dry place away from UV light and, if possible, in its original box.
Sources
This article is compiled from these sources; for technical values and obligations, the current edition of the source applies.
