Don's Home Home & Garden Protectants UV - Ultraviolet sunlight

SunGuard revivex UV protectant aersol $38 2 pack 23 oz each  4.6 (1,259)
Nikwax tent and Gear Solarproof 20 oz $20 4.5 (2,319)
Gear aid revivex uv protectant 4oz pump spray $12  4.2 (254)
ForceField UV SunBlock 23 oz $24 4.0 (978)
Scotchgard Outdoor water & sun shield spray 2 pack 10 oz each $20 4.6 (27,778)

Scotchgard
A 3M brand that can be used on fabric, furniture, and carpets to repel water and stains. Scotchgard Water and Sun Shield with UV Protector can help prevent fabric from fading and repels water more effectively on outdoor fabrics, suede, and leather. However, Scotchgard products contain petroleum distillate solvents and organofluorine chemicals, and one product is not suitable for outdoor furniture, leather, carpets, or rugs.
Petroleum jelly can degrade synthetic fabrics like nylon over time because it can infiltrate the fabric's porous pores.

Revivex UV Protectant
An environmentally safe, water-based product that can protect outdoor equipment from UV rays and restore its original appearance and color. Some say they use Revivex on tents to waterproof and protect the fabric.

Sling Protection Basics: How to Properly Maintain & Store Lifting Slings
Nylon, polyester, and other synthetic fiber materials are especially susceptible to chemical damage. However, nylon and polyester each have their own unique resistance to certain chemicals, so special consideration should be given to the type of synthetic sling you use in a chemically-active environment.

	Nylon	Polyester
Acids	No	*
Alcohols	Yes	Yes
Aldehydes	Yes	No
Strong Alkalis	Yes	**
Bleach Agents	No	Yes
Dry Cleaning Solvents	Yes	Yes
Ethers	Yes	No
Halogenated Hydrocarbons	Yes	Yes
Hydrocarbons	Yes	Yes
Ketonnes	Yes	Yes
Oils (Crude)	Yes	Yes
Oils (Lubricating)	Yes	Yes
Soaps & Detergents	Yes	Yes
Water & Sea Water	Yes	Yes
Weak Alkalis	Yes	Yes

* Disintegrated by concentrated sulfuric acid
** Degraded by strong alkalis at elevated temperatures