Hi swkeist5,
There is no consensus on which mattress or material is “best” for children but one of the most important issues for most parents is that their child’s mattress uses “safe” materials. There is also a lot more information in post #2 here and the more detailed posts and information it links to about safe, natural, organic, “chemical free”, and “green” mattresses and mattress materials that can help you sort through some of the marketing information and terminology that you will encounter in the industry and can help you differentiate between them and answer “how safe is safe enough for me” and that can help you decide on the type of materials and components you are most comfortable having in your child’s mattress and help you answer “how safe is safe enough for me”. These types of issues are complex and are generally specific to each person and their individual sensitivities, circumstances, criteria, beliefs, and lifestyle choices.
The only reliable way to to assess the “safety” of different materials in more general terms is based on lab tests and the certifications they have for harmful substances and VOCs so that you have some assurance than the VOCs are below the testing limits for the certification (see post #2 here for more information about some of the more reliable “safety” certifications). If the materials in a mattress or the mattress itself has a reliable “safety” certification then for most people they would certainly be “safe enough” … regardless of the type of material or the name of the manufacturer on the label.
While this applies more to babies and younger infants that are not yet able to change position … with too much soft material in a mattress the risk of suffocation with stomach sleeping increases for infants. This is more of an issue with memory foam than other materials (this of course is in addition to any chemical or offgassing issues from synthetic materials that young children may be more sensitive to than adults). I would avoid memory foam for younger children in particular (see post #2 here).
Once you have decided on the types of materials you are comfortable with then there are also some general firmness guidelines in post #2 here for choosing a mattress for a child in different age ranges that may also be helpful.
Any mattress that uses materials that are “durable enough” (see the durability guidelines here) that you would also consider to be “safe enough” and is in a suitable firmness range for their age would generally be a suitable choice for a child. The choice between different mattresses that meet these criteria (outside of memory foam) would really be more of a budget and preference choice than a “better/worse” choice (see this article).
There are also many forum posts and topics that discuss the different needs of children that may be helpful which also include some good sources for children’s mattresses as well. The better ones include this topic, and this topic, and this topic, and this topic, along with post #21 here and this topic, and this topic, and this topic and this topic and this topic, and this topic, and post #2 here, and this topic and this topic, and this topic, and this topic, and this topic and this topic (which includes links to some good information about cosleeping and bed sharing).
This topic and this topic and this topic and this topic and this topic also include some information and sources for crib mattresses
While this may seem like a lot of reading … most of the topics are fairly short and they include some very good options and sources for mattresses for children of all ages and will give you a very good sense of the types of mattresses and materials that will be the best “match” for your child and for the criteria that are most important to you. They would be well worth the hour or two it will take to read them and to read about the many good options that they include.
With the ages of your children … I wouldn’t be quite as concerned with offgassing and completely natural materials may not be as important as they would be for many people if their children were younger but this would be a judgement choice that each parent will need to make for their own children (although I still wouldn’t choose memory foam for younger children). Because children aren’t as developed and generally need firmer support and have different needs than adults … I would tend towards slightly firmer choices than the lighter, curvier, and more developed bodies of an adult would normally require. A mattress that would be comfortable for adults that prefer softer and more conforming comfort layers would likely be too soft for a child. You can also add a softer topper to any firmer childrens’ mattress when they get older and develop more adult proportions if and when they need a softer comfort layer in their “sleeping system”.
This means that a latex choice with a sleeping surface in the range of 28 - 32 ILD (medium range) would generally be better than softer as a general guideline although with more supportive materials like latex with smaller children then slightly softer would be less risky than other materials because of their lighter weight and frames and may also make a suitable choice. The quilting foam would also give them a little extra “cush” without affecting alignment and support.
Girls tend to prefer softer than boys.
Hope this helps.
Phoenix