Before considering PPE to protect people from excessive hot or cold pipework, have you investigated what engineering/physical controls are possible?

Thermal insulation, distance guards (typically wire mesh) fitted around the pipework.

Safety by distance - ie remove the need for people to go near very hot or cold surfaces or re-route pipework?

Process changes (less likely) - but do processes need to be so hot or cold? Energy saving benefit as well.

I'm a bit surprised that your process engineers haven't swathed the equipment in lagging. It's more likely to pay for itself than other solutions but failing that treat it a bit like dangerous machinery - fixed guards at a sufficient distance/mesh size to keep people away. Dear old PD5304 will help on this.

safetodo01
Your question was clear enough. I guess the lack of an answer suggests that there may not be widely accepted standards or guidelines.

From what I can gather, the requirements are purely to do what has to be done to prevent people contacting surfaces that are above or below the temperatures that can cause harm to the skin. Perfectly logical, but I think you probably understood that.

I have looked as a company standard I have access to. It refers to momentary and prolonged contact. For low temperatures the requirement is to prevent contact to anything below 0C for both situations. For high temperatures the limits are 65C for momentary and 49C for prolonged.

Not sure how helpful that is. However, as stated lagging introduces other risks and so needs to be considered carefully.