Decoding the Alphabet of Clean Air

When we design for a child's environment, our choices are guided by a simple reality that children do not just interact with furniture, they live with it. They breathe faster than adults, and on a body-weight basis, meaning they absorb more of the pollutants present in their immediate environment ①. Because of this physiological reality, their developing systems are far more sensitive to the spaces they inhabit.

True safety in furniture design is rarely visible. It is not found in a marketing slogan or a superficial finish, but in the deliberate choices made before manufacturing even begins. We select materials intentionally to ensure they are durable, safe for your family, and kind to the environment.

Recently, we made the conscious decision to transition our structural particle board to the global gold standard of air quality: F☆☆☆☆ (F4-star grade). This shift naturally impacts our production costs and product pricing, but when designing for the next generation, we refuse to compromise on material quality.

How the Standards Measure Up

When shopping for home furniture, parents are often confronted with a confusing alphabet of material grades - E1, E0, and F☆☆☆☆ (F4-star grade). To make informed decisions, it helps to understand where these standards originate and what they actually measure.

The 'E' grading system is the traditional European framework, established to regulate formaldehyde emissions in manufactured wood products. Under the European standard EN 13986, emission limits for the widely accepted E1 class are capped at ≤ 0.124 mg/m³ ②. These European grades are tested using a chamber method ③, which measures how much gas naturally floats out into a room's air space over time. While the European Union officially recognizes E1 standard, the industry eventually pushed forward to create the E0 grade as manufacturing capabilities improved.

The 'F-star' rating system, however, originates from the incredibly rigorous Japanese Agricultural Standards (JAS) ④. Unlike the European framework, the Japanese standard uses a desiccator method to test materials ⑤. This process suspends the wood core directly over water. The water acts like a sponge, forcing out and trapping chemical molecules from deep within the wood layers. Developed specifically to combat indoor air quality issues in modern residential spaces, it stands today as the strictest framework in the world.

The crucial difference lies in how these boards are permitted to be used. Under the Building Standard Law of Japan, materials that carry the F☆☆☆☆ (F4-star grade) are designated as having the absolute lowest levels of hazardous substance emissions and are subjected to no usage area restrictions within residential architecture ⑥. It requires emissions to be a fraction of E0 boards, making it the safest possible choice for closed, intimate spaces like a child's bedroom.

A Balanced & Purposeful Approach to Materials

Maintaining an honest approach to design means recognizing that different materials serve different structural purposes. We do not blindly chase single material labels for marketing appeal, we select the right grade for the right technical job.

Our upgraded F☆☆☆☆ (F4-star grade) particle board provides multidirectional stability and flexural strength, making it ideal for larger, structural pieces to bear weight without warping over time. At the same time, we intentionally select E0 grade Medium-Density Fiberboard (MDF) or solid wood multilayer board for specific components. These specialized material types do not come in F4-star grades, so we use the highest standard possible (E0 grade) for them. We use MDF for the back panels of some of our Plus and Cube Max cabinets to achieve a slim profile that particle boards cannot provide, and for the shelving of our No. 1 Desk to ensure a smooth finish for a better effect. These selections ensure the highest standards of safety and environmental compliance throughout the manufacturing process.

The Full Scope of Safe Design

When we invest in material upgrades like F☆☆☆☆ (F4-star grade) particle boards, eco-friendly water-based paints, and FSC-certified solid woods, the impact extends beyond the walls of your child's bedroom.

Real sustainability and ethical production consider the entire lifecycle of an object, including the environment where it is produced. The decision to eliminate toxic chemical solvents and reduce emissions to a global minimum directly shapes the workplace environment within our factories. The craftsmen turning these raw elements into functional furniture breathe the same air on the factory floor every single day. Protecting their well-being is just as vital to our brand mission as protecting the families who welcome our products into their homes.

We choose durability and responsibility. Transparent choices, intentional material sourcing, and honest pricing are the terms of our partnership with you. Thank you for choosing a safer, more intentional path for the spaces where your children grow.

Data Sources

① World Health Organization (WHO), 2018
② European Commission (EC), 2023
③ Environmental Protection Agency (EPA), 2009
④ Japanese Standards Association (JAS), 2015
⑤ Ministry of Agriculture, Forestry and Fisheries of Japan (MAFF)
⑥ Ministry of Land, Infrastructure, Transport and Tourism of Japan (MLIT), 2003

💭 Food for Thought

In case you are wondering why we do not just use solid wood instead of particle board for the selected products - we actually tried it. Read more about what we learned in our blog post, Think Out of the Cube.