MYP Design Product Safety and Standards Notes

Safety Is Designed In, Not Labelled On

1. A hazard is the thing that can cause harm, such as a spinning blade, while the risk is how likely that harm is and how bad it would be.
2. Designers work down an order of preference: remove the hazard, then guard it, then warn about it.
3. Removing beats guarding, so a toy with no removable wheels is safer than one with a warning sticker about the wheels.
4. A warning is the weakest control because it depends on a user reading it, understanding it and remembering it at the wrong moment.
5. Design for foreseeable misuse as well as correct use, because somebody will stand on the chair, pull the cable and put the small part in their mouth.

Sharp Edges, Trap Points and Things That Tip Over

1. Every cut edge starts sharp, so laser-cut acrylic gets a light file and a polish, sheet steel gets deburred, and 3D printed parts get their raft scars sanded off.
2. Round external corners rather than leaving them square, and a radius of 2 mm to 3 mm is enough to turn a cutting edge into a blunt one.
3. Trap points are gaps that close on a finger, and folding chairs, hinged lids and scissor mechanisms are the usual offenders.
4. A common rule of thumb is to keep a moving gap either too small for a finger to enter, under about 5 mm, or wide enough that it can never pinch, over about 25 mm.
5. Stability comes from a wide base and a low centre of mass, which is why a tall thin lamp needs a heavy foot.
6. A standard tip test is to stand the product on a 10 degree slope and check it does not topple in any direction.
7. Tall furniture that a child might climb needs an anti-tip bracket into the wall, because a chest of drawers with every drawer open has its centre of mass outside its base.

Small Parts, Cords and Age Warnings

1. Children under three put everything in their mouths, so any part that comes off is checked for choking.
2. Testers use a small parts cylinder of about 31.7 mm diameter and 57.1 mm deep, and anything that drops fully inside it is a choking hazard for that age group.
3. Parts are pulled as well as measured, since a button eye that survives a firm pull test stays on a soft toy in real use.
4. Cords and loops strangle, which is why blind cords now come with breakaway connectors and cleats, and cot toys have strict limits on string length.
5. The crossed-out 0 to 3 symbol is the standard age warning meaning not suitable for children under 36 months, and it has to say why, such as small parts.
6. An age warning is a label for the buying adult, so it never replaces making the part too big to swallow in the first place.

Materials That Can Poison or Burn

1. Toxicity rules cover what can migrate out of a material into a mouth or a hand, which is why lead and cadmium are restricted in toy paints and coatings.
2. Use finishes labelled toy safe or food safe for anything handled by children or touching food, rather than a general purpose gloss from the workshop shelf.
3. MDF dust carries formaldehyde from the resin binder, so cut it with extraction running and a mask on, and seal the edges afterwards.
4. Solvent cements for acrylic give off fumes that need ventilation, and superglue bonds skin fast enough that gloves are sensible.
5. Printing ABS releases more unpleasant fumes than PLA, so an enclosed printer with filtration is the safer classroom setup.
6. Flammability matters for anything soft or worn, and upholstery foam and children's nightwear both have their own fire test requirements.

Electrical Safety Has Its Own Rules

1. For a school project, work at low voltage from a 5 V USB supply or a battery pack, and never wire mains voltage into your own prototype.
2. Mains products are built either as Class I, with an earth wire to the metal casing, or Class II, double insulated and marked with a small square inside a square.
3. A UK plug carries a fuse matched to the appliance, typically 3 A for a lamp or a radio and 13 A for a kettle or a heater.
4. Cables need strain relief where they enter a casing, because the failure is almost always someone yanking the lead and pulling a conductor off its terminal.
5. An IP rating states protection against solids then liquids, so IP65 means dust tight and safe against water jets, which is what a bathroom or outdoor product needs.
6. Lithium cells catch fire when crushed, punctured or overcharged, so a battery needs a rigid pocket in the casing rather than being taped to the inside.

Standards Bodies and Safety Marks Mean Different Things

1. ISO, the International Organization for Standardization, writes standards used worldwide, including ISO 7250 on body measurements for design.
2. BSI, the British Standards Institution, publishes standards numbered BS, and BS EN in front of a number means a European standard adopted in the UK.
3. The Kitemark is BSI's own certification symbol, and it is only awarded after independent testing plus continuing factory checks.
4. The CE mark is the manufacturer's own declaration that a product meets the relevant European rules, so it is a passport for sale rather than a quality award.
5. The UKCA mark, standing for UK Conformity Assessed, does the same job for goods placed on the market in Great Britain.
6. Toys sold in Europe are tested against the EN 71 series, which covers mechanical hazards, flammability and chemical migration in separate parts.
7. The Lion Mark is a British toy industry symbol showing the maker signed up to its code of practice, and shoppers often read it alongside the CE or UKCA mark.

Test It Before the Client Ever Touches It

1. Run a finger check first: slide a hand over every surface, edge and opening of the finished prototype and mark anything that catches.
2. Do the tip test on a 10 degree slope and the drop test from the height it will actually fall from, which is table height for most products.
3. Pull, twist and lever every removable part, then check anything that came off against the small parts cylinder if children are in your user group.
4. Leave it running or loaded for a realistic period, since a motor that is warm after two minutes may be dangerous after twenty.
5. Ask a teacher to check any electrical work before it is powered, and keep the prototype supervised during its first user test.
6. Write down each test, what you were looking for and what happened, because an untested claim of safety is worth nothing to a client.