What is "Nursery Foam" and How Do I Know If It's Good Quality?

Thank you so much for asking this question!

Let's start by saying "Nursery Foam" or "Special Nursery-Grade Foam" is NOT a legally defined material. Manufacturers use "Nursery Foam" to imply suitability for babies, but there's no guarantee of its quality or performance.

How Foam is Measured

Foam is measured in density (kg/m³) and also hardness (Newton rating). By using the term "Nursery Foam" and not disclosing the rating, manufacturers are disguising cheap quality foam.

If a company was proud of the foam it's using in its mattress, it would disclose its rating with pride, saying for instance "our foam is 35/135".

No foam rating = low transparency. When a brand doesn't disclose foam density or hardness, it's often because the foam is low-cost and low-density. It wouldn't sell if it was called "low-grade foam" instead of "Nursery Foam"!

Ratings such as 35/135 or 50/130 indicate higher-quality foams. They offer more firmness combined with support and comfort, and of course more durability. Yes, they cost more, but at least you can see what you're getting for your money. I agree it's not easy to sort the real from the fluff!

A Simple (Sort of!) Guide to Foam Ratings

How foam is measured is a little complicated, but here's a simple non-tech guide - well, sort of. I'll do my best!

Density - How Heavy the Foam Is

Think of it like cake: compare a light sponge to a rich fruitcake of the same size. That's density (weight and size combined). The higher the density of foam, the stronger and longer lasting it is.

Density is measured in kg/m³ (kilograms per cubic metre), so 35kg will be a considerable improvement on a foam rating of 26kg (your "special grade nursery foam").

The old British Standard graded foam into these sections:

• L (Light use): 18 kg/m³
• A (Average use): 24 kg/m³
• S (Severe use): 28 kg/m³
• VS (Very Severe use): 36 kg/m³
• X (Extreme use): 50 kg/m³

Hardness - How Firm the Foam Feels

This is measured in Newtons. "Please don't leave me now!" ;)

The Newton measurement is how much weight it takes to squash a 10cm deep piece of foam down to 4cm.

So a cheap piece of foam (A 24 kg/m³) might only need 120 Newtons to squash it down, giving it a measurement of 24/120.

But a quality piece of foam (VS 36 kg/m³) might need 135 Newtons to squash it down, giving it a measurement of 36/135.

What the Numbers Mean in Practice

It's a difficult choice to find the right balance between density and hardness when we're looking for perfection - the perfect mattress offering the best comfort, support, and durability. Fortunately, good manufacturers have been doing this for over 40 years.

New foams are being developed all the time. For instance, a TCPP-free 50/130 foam used 2.5cm deep to cover pocket springs would give the ultimate in support, comfort, and durability.

Poor Quality Foam

Density 20-25, hardness 100-120. This is cheap and will lose shape quickly, has poor support and recovery, and is definitely not durable. Sorry, but that's "nursery foam" - though in all fairness, it is inexpensive.

Top Quality Baby Mattress Foam

Density 35-40, hardness 135-150. Safe, firm, excellent comfort, support, and good recovery. Highly durable and will give you the 5 years needed in a cot bed.

I would say you'd have to buy three cheap "nursery foam" mattresses to last you 5 years, compared to one top-of-the-range mattress.

Why This Matters for Pocket Sprung Mattresses

This is very important when you buy a pocket sprung mattress. The sprung unit is separate and encapsulated in foam.

The sprung unit is 5cm deep. The recommended British Standard for a cot mattress is 10cm. So only 2.5cm depth of foam is added to each top and bottom. (5 + 2.5 + 2.5 = 10) I got maths O-level!

Your baby's weight goes from 7lbs at birth to 50lbs average weight at 5 years old. Take into account the gymnastics, and you sitting on the side of the bed reading a story - all this to be handled by 2.5cm of foam! Cheap foam won't "cut the mustard" - you need high-density foam to perform these tasks.

The Bottom Line

In this day and age when price is a huge factor, I'm not saying a cheap mattress calling itself "nursery foam" is either unsafe or not worth the money for the job it will do.

What I am saying is: buy with informed choice. Don't be fooled when you see meaningless marketing descriptions like "Quality Nursery Foam" or "Cot Foam" implying you're getting a top-grade product when you're not!