Hi I have purchased a portacot lambs wool underlay for my portacot. My son will be 14 months when we go away. At his age, is it safe to use? We have a fitted sheet that goes in the top to get the wool in place.

Red Nose recommends that a baby should be placed for sleep on a firm, clean, well-fitting mattress & to avoid anything on the mattress that may create a soft surface. This includes sheepskins.

While the risk for asphyxiation due to soft mattress is low in babies over 12mths, the general recommendation is continue placing him on a firm surface while he is in the cot.

Product Safety Australia (ACCC) has the following information about Portable cots.
Ensure that the mattress, padding and cushioning material is sufficiently firm to prevent it from moulding to a child’s face.
https://www.productsafety.gov.au/products/babies-kids/kids-furniture/folding-cots

Red Nose has the following
Only use the firm, thin, well-fitting mattress that is supplied with the portable cot. Never add a second mattress or additional padding under or over the mattress, which has been specifically designed for the portacot, as baby may become trapped face down in gaps between the mattress and the sides.
https://rednose.org.au/article/portable-cots