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If Labour Canada was in your facility, it must be one of those Ontario workplaces covered by federal jurisdiction. If so, the Canada Occupational Health and Safety Regulations - SOR/86-304 would apply.
Here are some excerpts from PART XIV, MATERIALS HANDLING that might be of use. Note especially rule 14.44(1) - 750mm. (approximately 30 inches).

Materials Handling Area
14.38 (1) In this section, "materials handling area" means an area within which materials handling equipment may create a hazard to any person.
(2) An employer shall cause warning signs to be posted, or a signaller to be in control, at the approaches to any materials handling area while materials handling operations are in progress.
(3) Only the following persons may enter a materials handling area while materials handling operations are in progress:
(a) a health and safety officer;
(b) an employee whose presence in the materials handling area is essential to the conduct, supervision or safety of the materials handling operations; or
(c) a person who has been authorized by the employer to be in the materials handling area while materials handling operations are in progress.
(4) If any person other than a person referred to in subsection (3) enters a materials handling area, the employer shall cause the materials handling operations in the immediate vicinity of the unauthorized person to be immediately discontinued and to remain discontinued until the person has left that materials handling area. SOR/88-68, s. 14; SOR/88-632, s. 67(F); SOR/94-263, s. 65(F); SOR/96-400, s. 1; SOR/2002-208, s. 38.

Aisles and Corridors
14.44 (1) An employer shall provide a clearly marked pathway for the exclusive use of pedestrians and persons using wheelchairs and other similar devices that is not less than 750 mm wide along one side of an aisle, corridor or other course of travel that is found in a work place and that
(a) is a principal traffic route for mobile equipment, pedestrians and persons using wheelchairs and other similar devices; and
(b) exceeds 15 m in length.
(2) Subsection (1) does not apply where a signaller or traffic lights are provided for the purpose of controlling traffic and protecting persons.
(3) Where an aisle, corridor or other course of travel that is a principal traffic route in a work place intersects with another route, an employer shall cause warning signs marked with the words "DANGEROUS INTERSECTION - CROISEMENT DANGEREUX", in letters not less than 50 mm in height on a contrasting background, to be posted along the approaches to the intersection.
(4) At blind corners, mirrors shall be installed that permit a mobile equipment operator to see a pedestrian, a person using a wheelchair or other similar device, a vehicle or mobile equipment approaching the blind corner.SOR/96-400, s. 1; SOR/96-525, s. 15.

Clearances
14.45 (1) In any passageway that is regularly travelled by motorized or manual materials handling equipment, the employer shall ensure that
(a) an overhead clearance is at least 150 mm above
(i) that part of the materials handling equipment or its load that is the highest when the materials handling equipment is in its highest normal operating position at the point of clearance, and
(ii) the top of the head of the operator or any other employee required to ride on the materials handling equipment when occupying the highest normal position for the operator or employee at the point of clearance; and
(b) a side clearance is sufficiently wide to permit the motorized or manual materials handling equipment and its load to be manoeuvred safely by an operator, but in no case less than 150 mm on each side measured from the furthest projecting part of the equipment or its load, when the equipment is being operated in a normal manner.
(2) Where an overhead clearance measured in accordance with subparagraph (l)(a)(i) or (ii) is less than 300 mm, the employer shall cause
(a) the top of the doorway or object that<