Polyester slings are unsuitable around which substances?

• A. Concentrated Alkalis and Sulfuric Acids
• B. Water and Air
• C. Oils and Solvents
• D. Aldehydes

Answer: (A)

Polyester slings have limited chemical compatibility. The polyester fiber can undergo hydrolysis when exposed to strong chemicals, especially concentrated bases and strong acids. Concentrated alkalis can break down the ester bonds in the polymer, and concentrated sulfuric acid can attack the polymer chains, weakening the slings and raising the risk of failure under load. In contrast, water and air cause no chemical attack, and polyester slings are generally resistant to many oils and solvents and tolerate aldehydes under normal conditions. So the substances that pose a real risk to polyester slings are the concentrated alkalis and sulfuric acids.