What natural latex is

Natural latex is a foam made from the tapped sap of the rubber tree, Hevea brasiliensis, cured into a molded block or cut into shredded fill.

Where does natural latex come from?

Sap tapped from the rubber tree, about 30% rubber when fresh, kept liquid with ammonia and concentrated to about 60% before it is foamed.

A tree is first tapped at 5 or 6 years old and gives roughly 50 g of solid rubber per tapping (Britannica). Collectors add ammonia at 0.3% to 0.8% by weight, and a centrifuge lifts the rubber content to 60% (Physics Procedia, 2009). Our guide to how natural latex is made takes each step in order.

What does natural content actually describe?

The share of the foam's rubber that came from trees rather than from synthetic rubber. Curing agents make up a few percent of any latex foam.

One maker puts foam sold as 100% natural at 95 to 97% natural rubber, with a curing package making up the rest (Savvy Rest). A common blend is 30% natural and 70% synthetic (Mayers Bedding). Only 3 of the 9 pillow pages we read gave a percentage. Our guide to reading the percentage on a label shows what to ask when a page gives none.

Why does residual protein matter?

Latex allergy is a reaction to proteins in natural rubber. Washing the foam reduces them but does not make latex safe for someone who is allergic.

Published estimates for the general population run from about 1% (ADA) to 4.3% (Wu et al., 2016). Factories wash and dry each core after curing, yet none of the 21 pillow listings we read mentioned that step, so ask the seller if it matters to you.

What does organic add?

A certificate. The Global Organic Latex Standard requires at least 95% certified organic natural rubber in the product's polymer content and allows no synthetic latex.

The rule comes from version 3.0 of the standard (GOLS 3.0), and transaction certificates trace the latex from plantation to retailer (Control Union). Our guide to whether a natural latex pillow is worth it sets out what each label on a pillow page proves.