NEW TEXT

<em>Spiral stairways</em> are permitted to be used as a component in the <em>means of egress</em> only within <em>dwelling units</em> or from a space not more than 250 square feet (23 m<sup>2</sup>) in area and serving not more than five occupants, or from <em>technical production areas</em> in accordance with Section 410.6.
<div class="secondParagraph">A <em>spiral stairway </em>shall have a&nbsp; &nbsp; &nbsp;6 3/4 inch (171 mm) minimum clear tread depth at a point 12 inches (305 mm) from the walkline. The risers shall be sufficient to provide a headroom of 78 inches (1981 mm) minimum, but riser height shall not be more than 91 /2 inches (241 mm). The minimum <em>stairway </em>clear width at and below the <em>handrail </em>shall be 26 inches (660 mm).</div>

OLD TEXT

<p><i>Spiral stairways</i> are permitted to be used as a component in the <i>means of egress</i> only within <i>dwelling units</i> or from a space not more than 250 square feet (23 m<sup>2</sup>) in area and serving not more than five occupants, or from <i>technical production areas</i> in accordance with Section 410.6.</p>
<div class="secondParagraph">A <i>spiral stairway </i>shall have a 7<sup>1</sup> /<sub>2</sub> <sub>-inch (191 mm) minimum clear tread depth at a point 12 inches (305 mm) from the narrow edge. The risers shall be sufficient to provide a headroom of 78 inches (1981 mm) minimum, but riser height shall not be more than 9</sub><sup>1</sup> /<sub>2</sub> <sub> inches (241 mm). The minimum </sub><i><sub>stairway </sub></i><sub>clear width at and below the </sub><i><sub>handrail </sub></i><sub>shall be 26 inches (660 mm).</sub></div>