Features of Snell's Ski Helmet Standard

As with other Snell standards, S-98 and RS-98 do not specify all the helmet an individual might need but merely as much helmet as one might reasonably be expected to wear. We have considered the use environment and the nature of winter sports and weighed these considerations against the capabilities of various protective helmet configurations. The requirements set forth in S-98 and RS-98 represent our best advice to skiers, snowboarders and to the entire winter sports community. Go To S-98 or RS-98 Standards.

The requirements include:

Impact Testing for S-98:

• One impact per site
• Peak acceleration not to exceed 300 g
• Flat anvil impact @ 120J (2.45 m)
• Hemispherical and edge anvil impacts @ 100 J (2.05 m)

Penetration Testing:

• 3 kg conical penetrator dropped through 1 meter.

• Shock load with a maximum deflection criteria

• Comparable to M-95 but with a 30 mm footprint allowance. The test line is 15 mm higher than B-95 in front, approximately 5 mm higher on the side and approximately 25 mm lower in the rear. However, the impact severities are such that reasonable helmet designs will also meet all the requirements of the B-95 easily.

The impact test levels represent a moderate increase over those of the standard withdrawn in 1990.

The following table compares S-98 with other helmet standards:

	S-98	RS-98	Snell '73	ASTM	EN1077
Impact: Flat Hemisphere Edge	(300 g) 120 J 100 J 100 J	(300 g) 100 J 80 J 80 J	(300 g) 90 J 90 J -	(300 g) 74 J - -	(250 g) 70 J (size Med) - -
Test Line: (size Med) Front Rear	83 mm 23 mm	83 mm 23 mm	53 mm + -7 mm +	77.5 mm 27.5 mm	80 mm 40 mm
Penetration	1 m	1 m	1 m	1 m	0.75 m
Chin Bar	Full Face Only	Full Face Only	-	-	-

The CEN impacts vary according to the cube of headform circumference. The smallest headform (circ. 50 mm) would imply a severity of less than 48 J, the largest at 62 mm would imply a severity slightly greater than 95 J. The 70 J figure given is based on the medium sized headform.

The test lines mark the lower boundary of the test area on the helmet. Since the procedures for marking the helmets vary, the table shows only the positions of this boundary at the front and back of the head. The figures given are all based on the medium size headform and are shown as distances up from the basic (anatomical Frankfort) plane.

The S-98 and RS-98 test lines have been set to require the greatest head coverage possible. The limitations on these lines depend on visual field requirements, neck articulation and on the current state of the helmet makers' art. Until there is an advance in helmet technology it will be impractical to set these lines any closer to the helmet's edge.

The figures given in the table for the old Snell ski helmet standard test line do not include any allowance for helmet performance at or near the edge of the required coverage. However, Dr. Snively and Dr. Chichester routinely made such allowance during testing based on their expert knowledge of helmet construction and helmet evaluation.

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