FMVSS 226 Ejection Mitigation: Coverage, Testing, and Compliance

Federal Motor Vehicle Safety Standard No. 226, the ejection mitigation rule, requires manufacturers to build systems into covered vehicles that keep occupants from being thrown through side windows during a crash, especially a rollover. NHTSA published the rule in January 2011 to address the leading killer in rollover crashes: partial or full ejection. Rollovers make up about three percent of crashes but cause roughly a third of occupant deaths, and ejection drives most of that toll.

Which Vehicles the Standard Covers

FMVSS 226 applies to passenger cars, multipurpose passenger vehicles, trucks designed to carry at least one person, and buses with a gross vehicle weight rating of 4,536 kilograms (10,000 pounds) or less. It covers side window openings next to the first three rows of seating and any window openings in a cargo area behind those rows. Windshields and windows too narrow for an occupant’s body to pass through are outside the scope.¹

Several vehicle types are excluded. Convertibles, walk-in vans, and vehicles with modified roof structures do not need to comply. Neither do vehicles with no doors or with doors designed to be easily removed for operation. Law enforcement vehicles, correctional institution vehicles, and taxis or limousines with a fixed security partition between rows are also excluded, provided they were produced by more than one manufacturer or were altered after initial manufacture.¹

What the Standard Requires

The performance requirement is a single number. When a test device simulating a human head strikes the side window area, the outermost surface of that device cannot travel more than 100 millimeters past what the regulation calls the “zero displacement plane,” which is essentially the inside surface of the window glass. Go past 100 millimeters, and the vehicle fails.¹

Manufacturers meet that number in one of two ways. The common approach is an advanced side curtain airbag that deploys during a rollover or side impact and stays inflated long enough to cover the window opening throughout a prolonged event. The alternative is high-strength glazing that resists penetration. The rule explicitly bars relying on movable glazing alone, so a closed power window does not count as a compliant countermeasure. Whatever the manufacturer chooses, the system must activate automatically, without any action from the occupant.¹

How Compliance Is Tested

NHTSA verifies compliance with a guided impactor. The device, called the ejection impactor, is a featureless headform on a shaft with a combined mass of 18 kilograms, propelled into target locations around the perimeter of the side daylight opening. Target points are set by a prescribed geometry, not chosen freely.¹

For a vehicle with a deployable countermeasure such as a side curtain airbag, the test runs twice. The first impact comes 1.5 seconds after the countermeasure activates, at 20 km/h; this checks whether the system covers the window fast enough. The second comes 6.0 seconds after activation, at 16 km/h, and checks whether the system stays inflated long enough to protect occupants during a sustained rollover. For the second impact, any movable glazing is removed or fully retracted so only the countermeasure itself is tested. At both impact points, the headform cannot push more than 100 millimeters past the zero displacement plane.¹

When the Rule Took Effect

NHTSA phased FMVSS 226 in over four model years starting September 1, 2013, with rising percentages of each manufacturer’s production required to comply. Since September 1, 2017, every covered vehicle manufactured for sale in the United States must comply, and advance credits from the phase-in are no longer available.¹

Certification, Readiness Indicator, and Penalties

Like all federal motor vehicle safety standards, FMVSS 226 works through self-certification. The manufacturer certifies that its vehicles meet the standard before they reach the market, and NHTSA conducts compliance testing on production vehicles afterward. The agency can require technical documentation at any time.

Vehicles equipped with a deployable ejection mitigation countermeasure must include a monitoring system with a readiness indicator visible to the driver. Manufacturers can use the same readiness indicator already required under FMVSS 208 for the supplemental restraint system, so a single dashboard warning light may serve both. The owner’s manual must describe the ejection mitigation system, explain the readiness indicator, list the elements being monitored, and tell the driver what to do if the light comes on.¹

A manufacturer that sells a noncompliant vehicle faces civil penalties and potential recall obligations. Under the current inflation-adjusted schedule, the fine can reach $27,874 per violation, and each noncompliant vehicle counts as a separate violation.² When NHTSA finds a defect or noncompliance, the manufacturer must notify owners and either repair the vehicle at no cost, replace it, or refund the purchase price. For FMVSS 226, that usually means replacing or reprogramming the side curtain airbag system.

What This Means for Vehicle Owners

If you drive a vehicle built after September 2017 and it isn’t in an excluded category, it has an ejection mitigation system. In most vehicles that system is a side curtain airbag designed to stay inflated longer than a standard side-impact airbag. The dashboard readiness indicator, usually shared with the airbag warning light, tells you whether the system is functioning. If the light stays on after you start the vehicle, have it inspected by a dealer or qualified technician.

After any collision, even one that didn’t deploy the airbags, a diagnostic scan of the restraint system is worth considering. Sensor or wiring damage from a minor impact can disable the ejection mitigation system without triggering the warning light, and that risk is higher after a side impact or a hit near the roof rail where the side curtain airbag is housed.