Making and Handing Something Over Means Taking Professional Responsibility
Handing something you made to another person. Selling it. Giving it as a gift. Selling the data. All of these are acts of making something and delivering it.
But wait.
From the moment you hand it over, you bear responsibility for that object. What the recipient does with it, how they use it, who touches it — these are no longer within your control. But the responsibility remains.
This article is not written to blame anyone. It is written to raise awareness by sharing knowledge that is taken for granted in the manufacturing industry but has not reached individual makers, through concrete examples.
One thing to note in advance: the author is not a legal professional. This article does not provide legal judgments. Its purpose is solely to raise awareness that these issues exist. For judgment and action on individual cases, please consult a qualified professional such as a lawyer. Knowledge is only the entrance to awareness. Beyond that, always seek the help of professionals.
Additionally, while the issues covered in this article are globally relevant, all legal and regulatory references are based on Japanese law. Readers outside Japan are encouraged to verify the applicable laws in their own jurisdiction.
For issues related to intellectual property rights, data distribution, scanning, and social media posting, please refer to the companion article “What You Need to Know Before Starting 3D Printing (1/2): Rights Edition.”
What Is the Product Liability Act? Why “I Didn’t Know” Is Not an Excuse
The Product Liability Act (PL Act) came into force in 1995. It establishes that when a defect in a manufactured product causes harm to a person’s life, body, or property, the victim may seek compensation from the manufacturer.
The most important aspect of this law is the concept of “no-fault liability.”
In ordinary claims for damages, the victim must prove the other party’s intent or negligence. Under the PL Act, however, this is different. If a product has a defect and damage occurs, liability arises from that fact alone. “I had no bad intentions,” “I didn’t know,” and “I was just doing it as a hobby” do not provide immunity.
And this PL Act applies to individual handmade sales. If a 3D-printed product sold on BOOTH or Minne causes harm to a buyer, the seller may be held responsible as the manufacturer, even if the sales were an extension of a hobby.
The PL Act defines three types of defects.
Design defects arise when a product becomes dangerous due to a design that does not consider safety. Manufacturing defects arise when safety is compromised during the manufacturing process due to material contamination or assembly errors. Instruction and warning defects arise when safety is compromised by failing to communicate information necessary to avoid danger.
The third type is particularly important. Even if the product itself has no problem, there is a possibility of bearing responsibility for “failing to communicate how to use it safely.”
The Gray Zone Between Hobby and Business
Many people believe that “the PL Act doesn’t apply because I’m just doing this as a hobby.” This judgment is extremely risky.
The “manufacturers” to whom the PL Act applies refers to those who manufacture or process goods “as a business.” “As a business” means conducting the activity repeatedly and continuously as part of a business operation. However, there is no clear legal threshold for how many times a sale must occur before it constitutes “as a business.”
This is where the gray zone emerges.
“I sold a few things I made as a hobby.” “I occasionally list items as a side income.” “I made something for a friend who paid me.” These situations may seem too small in scale to constitute a business. However, if items are repeatedly listed and sold on BOOTH or Minne, this may well qualify as “repeated and continuous” activity and fall under “as a business.” Furthermore, even a first-time sale may be included if the seller intends to continue selling in the future.
What about giving something to a friend for free? The PL Act applies upon “delivery,” so even if no payment is involved, there is a possibility of being held liable under civil law for illegal conduct if harm occurs.
The boundary between hobby and business is judged by the reality of the conduct, not the seller’s own perception. The more ambiguous that reality is, the longer the risk of remaining in a gray zone. When in doubt, consult a professional.
The True Purpose of That Instruction Sheet in the Box
When you buy a product, there is often a sheet of instructions and warnings inside. Most people have never read it.
But that sheet exists not to protect you, but to protect the person who made it.
Looking at what professional manufacturers write on that sheet, the precision is striking.
Age specifications (“for children 3 and older,” “use under adult supervision”), usage conditions (“keep out of direct sunlight,” “do not use when wet,” “maximum load capacity: XX kg”), prohibitions (“keep away from open flames,” “do not disassemble,” “do not put in mouth”), warnings (“stop use immediately if broken,” “contains small parts — choking hazard”), and manufacturing information (manufacturer name, contact information, date of manufacture, material names, country of origin).
None of this is courtesy. It is everything necessary to protect the maker from legal liability.
You cannot control how a buyer uses your product. Rather than hoping they use it correctly, the professional manufacturer’s approach is to design with the question: “Would anyone get hurt even in the worst case of use? And at minimum, have I warned them?” The instruction sheet is the evidence of that.
To avoid being held responsible for instruction and warning defects, you must get ahead of every foreseeable use case. That sheet is the proof that you did.
Does the product listing for a 3D-printed item you sell contain any of this? In most cases, the answer is no.
How Far Professional Manufacturers Actually Go
There are manufacturing processes that individual makers know nothing about — the invisible steps of the manufacturing industry.
Before a product reaches a consumer, professional manufacturers go through at least four inspection stages.
Incoming inspection verifies that purchased materials and components meet standards. In-process inspection verifies that production follows specifications. Final inspection verifies that the finished product meets requirements. And outgoing inspection verifies that quality is maintained even after packaging and storage.
Furthermore, outgoing approval requires checking not only quality test results but also manufacturing records, equipment cleaning records, label management records, anomaly reports, and certificates of analysis before approval is given.
For an individual who prints and sells with a 3D printer, none of this process exists.
In manufacturing, roles are also divided. There are people who make things, quality assurance departments who manage quality, and specialist teams who verify safety. Each checks the others. Individual makers must handle all of this alone. Without knowledge, no one will stop them.
The Blind Spot: What You Use During the Process Is More Dangerous Than the Filament
More individual makers are becoming aware of the safety of filaments and resins. However, awareness of what is used during the manufacturing process itself is close to zero. This is the most serious blind spot.
Here is a list of what is commonly used in 3D printing processes.
Glue sticks and hairspray for bed adhesion. Alcohol and acetone for support material removal. Epoxy resin and coating agents for surface finishing. Acrylic paint and lacquer for painting. Instant adhesive and epoxy adhesives for bonding. UV resin coatings for finishing. IPA (isopropanol) for washing resin prints.
Any of these can remain on the surface of a product and be shipped with it.
“Hairspray is safe for use on the body, so it must be safe” is a serious misconception. What is safe for direct application to the human body and what is safe when it remains on the surface of a product that a child touches or puts in their mouth for extended periods are judged by entirely different standards.
Imagine this scenario.
Hairspray was used for bed adhesion. It remained on the surface. The product was sold as a children’s figurine. A child who purchased it put it in their mouth. A chemical entered their body. A health problem arose.
In this case, the manufacturer would be asked: “Did you record what you used in the process?” “Did you confirm that the material would not remain on the product?” “Did you consider the possibility that a child might touch it and conduct safety verification?” “Did you include a warning about this in your instructions?”
If you cannot answer all of these, there is a possibility of bearing responsibility for a manufacturing defect or an instruction and warning defect.
The ultrafine particles (UFP) and volatile organic compounds (VOC) generated during 3D printing also cannot be ignored as health risks for the maker. ABS and ASA are of particular concern, and even PLA may contain harmful substances. Extended use in poorly ventilated indoor spaces raises concerns about respiratory and cardiovascular effects for the maker themselves.
When “It’s Not a Toy” Doesn’t Hold Up
“I sold this as a decorative item, not a toy.” There are situations where this argument does not hold up legally.
One of the criteria for judging defects under the PL Act is “ordinarily foreseeable use.” Safety is judged by considering not only the intended use by the manufacturer, but all the ways a consumer would ordinarily be likely to use it.
Consider the case of selling a figurine aimed at children as a “decorative item.”
Even if not sold as a toy, products that children may touch can be subject to regulations under the Food Sanitation Act. For items aimed at children under 6 years old, there are regulations on harmful substances including heavy metals and arsenic, and designated items include building blocks, dolls, blocks, and balls.
“I did not sell it as a toy” is not grounds for immunity. If it is foreseeable that a child would pick it up during ordinary use, the manufacturer may be held responsible for ensuring its safety.
In the toy industry, compliance with the ST mark (the voluntary safety standard of the Japan Toy Association), food sanitation inspections, physical safety testing (for choking, suffocation, puncture, and similar hazards), chemical safety testing (verification of 8 heavy metal elements), and biennial ongoing inspections are conducted as a matter of course.
If selling a 3D-printed figurine to households where it could be within a child’s reach, knowing these standards is the minimum level of responsibility.
The Hidden Risks in Decorative Items
The assumption that “a decorative item that just sits there is safe” is also risky.
PLA is the most commonly used material in 3D printing, but it shatters on impact. The sharpness of fragments when it falls can be dangerous. Its heat resistance is also low, at around 60 to 65 degrees Celsius, meaning it may deform or collapse on a sunny windowsill or in a car in summer.
A small tabletop figurine was sold. The next day, the buyer made contact. A child dropped it and cut their finger on a fragment. “I sold it as a decorative item” may not hold up against the question, “Was it not foreseeable that a child might pick it up?”
Consider also the warnings that professionals attach to decorative items, from the perspective of instruction and warning defects.
“Keep out of reach of small children.” “If dropped or broken, handle fragments carefully and dispose of immediately.” “Do not place in direct sunlight or high-temperature environments.” “This product is a decorative item. Keep away from food and beverages.”
Are any of these written on the listing page for a 3D-printed decorative item?
What Traceability Means as a Record
Professional manufacturers record which raw materials were used in which process to produce each product, and maintain the ability to trace this information. This is called traceability.
Why is it necessary? To identify what caused an accident when one occurs. And the fact that verification was performed can help reduce liability.
Under the PL Act, claims for product liability can be made within 3 years of the occurrence of damage, or within a maximum of 10 years of the product’s delivery. Records must be maintained throughout that period.
The minimum traceability that individual makers can start immediately is this.
Record the manufacturer, product number, and lot number of the filament used. Record all materials used in the process (glue, solvents, paint, adhesive). Record the date of manufacture and the content of any post-processing. This alone significantly increases your ability to respond when an accident occurs.
Minimum Steps to Take Starting Today
It is difficult for an individual to replicate everything that the manufacturing industry does. But the difference between writing nothing and writing something is enormous. Here is what you can do today.
Write instructions and warnings in your product listing Include material names, target age, prohibited uses (no food contact, no direct sunlight), response to breakage (handle fragments carefully, dispose immediately), and the manufacturer’s contact information. Writing it creates a record that you communicated this.
Keep manufacturing records Record the manufacturer, product number, and lot number of the filament used; all materials used in the process; the date of manufacture; and post-processing details — even as simple notes.
Be aware of process materials Glue sticks, hairspray, acetone, paint, adhesive — develop the habit of checking the SDS (Safety Data Sheet) to understand what components these contain. Be especially careful with products that children may touch.
Consider PL insurance Product liability insurance is available for individuals. It is worth considering as a risk hedge against potential damage claims. Relatively affordable group insurance options are available for handmade sellers.
Be especially careful with children’s items and food-contact items Toys, food-contact products, and anything that infants or young children might touch carry significantly higher risk. If selling any of these, consulting a professional is strongly recommended.
The Era When “I Didn’t Know” Is No Longer Acceptable
In manufacturing, “I didn’t know” does not hold up. Those who enter the manufacturing industry are placed within a structure that conveys necessary knowledge through industry customs, training programs, senior colleagues, and contractual relationships with business partners. There are separate people who make things, who manage quality, and who verify legal risks, all checking one another.
For people who begin making things with a 3D printer, however, that channel does not exist. The entry point is “a hobby.”
They watch how-to videos on YouTube, buy filament, and list on BOOTH. Nowhere in this flow do the PL Act, the Food Sanitation Act, manufacturing records, or traceability ever appear.
If anyone reading this article thinks “this is about me,” that is not criticism — it is the beginning of awareness. Knowing is the first step.
AM Insight Asia Perspective
The democratization of 3D printing manufacturing and sales is spreading rapidly across the world. In Asia and beyond, individual makers and small businesses are entering the space one after another in Europe and North America as well. Yet awareness of product liability remains far from sufficient across the industry as a whole.
What AM Insight Asia wants to emphasize in addressing this issue is not stricter regulation or enforcement. It is the development of educational infrastructure across the industry, and the protection of individuals from being unwittingly caught up in serious problems. People bearing responsibility without knowing it: knowledge is necessary to protect individuals from that kind of injustice.
To put it bluntly, it is as if Formula 1 cars have become affordable and beginners without a driver’s license are now driving them on public roads. Access to the technology has been democratized. But the knowledge and responsibility required to handle that technology have not been taught to anyone.
Writing this article brought a renewed and genuine appreciation for how much professional manufacturers consider in making the products they make. Verifying safety data sheets for materials, recording every chemical used in the manufacturing process, meeting Food Sanitation Act and toy safety standards, legally reviewing warning labels, multi-stage pre-shipment inspection, maintaining traceability for up to 10 years. All of this lies behind a single product that reaches a consumer’s hands.
This is what they do. We express genuine respect to every company and person involved in manufacturing across the world. The products we hold in our hands as a matter of course are built on an enormous accumulation of care and responsibility, invisible to us. The spread of 3D printing has made that invisible reality visible. That is a tremendous opportunity to cultivate a new maker culture built on genuine respect for the act of making things.
The democratization of manufacturing will not stop. That is precisely why the democratization of knowledge is urgent.
For issues related to intellectual property rights, data distribution, scanning, and social media posting, please refer to the companion article “What You Need to Know Before Starting 3D Printing (1/2): Rights Edition.”
