Slip-and-fall Incidents
Engineering analysis of slip-and-fall incidents involving indoor walking surfaces, outdoor facilities, and winter conditions
Slip-and-fall incidents are a common cause of personal injury in Canada and may occur in almost any environment, including stores, restaurants, office buildings, parking facilities, sidewalks, pedestrian areas, and other public and private premises.
From an engineering perspective, an important first step is to distinguish between indoor and outdoor slip-and-fall incidents, because the mechanisms that create a hazardous condition—and the standards and maintenance practices that apply—can be substantially different.
Indoor incidents commonly involve flooring that does not provide adequate slip resistance, contamination of the walking surface by water, oil, food, cleaning products or other substances, or a spill that was not promptly detected, cleaned, adequately warned against, or isolated from pedestrian traffic.
Outdoor incidents, particularly during Canadian winters, are more commonly associated with accumulations of snow or ice. However, outdoor incidents may also result from inadequate slip resistance of the walking-surface material itself, drainage conditions, surface deterioration, or other physical characteristics of the pedestrian facility.
Depending on whether a slip-and-fall incident occurred indoors or outdoors, the engineering analysis may require examination of the walking surface, measurement of its available friction, assessment of the applicable standards and guidelines, analysis of weather and pavement-temperature information, review of available inspection and maintenance records, and evaluation of whether reasonable measures were taken to identify, prevent, and address the hazardous condition.
The following sections describe some of the principal engineering considerations associated with indoor and outdoor slip-and-fall incidents.
If you are a legal counsel or an insurance professional handling a slip-and-fall claim and would like an engineering assessment of the circumstances, contact EDA Forensics for a complimentary preliminary review of the available information.
Indoor Slip-and-Fall Incidents
Indoor slip-and-fall incidents commonly occur when the friction available between a person's footwear and the walking surface is insufficient to provide the traction required during walking.
This may result from the characteristics or condition of the flooring material itself, or from contamination of an otherwise suitable surface by water, oil, food, cleaning products or other substances.
The slip resistance of a walking surface can be evaluated through its coefficient of friction (COF). Depending on the applicable standard and test method, the assessment may involve measuring either the static coefficient of friction (SCOF), the dynamic coefficient of friction (DCOF), or both.
The static coefficient of friction generally characterizes the resistance available before sliding begins. In practical terms, it relates to the force required to initiate movement between two surfaces.
The dynamic coefficient of friction, in contrast, characterizes resistance while relative sliding motion is occurring. It is therefore intended to evaluate frictional behaviour once sliding has begun.
Recognized floor-safety standards and test methods establish criteria for evaluating the measured values of SCOF and DCOF. Based on those measured values, an engineering assessment can be made on whether a walking surface was safe for public use.
At EDA Forensics, we have the specialized slip-testing equipment, as well as the required expertise, to measure the available coefficient of friction. The measured values can then be compared with the criteria contained in the applicable standards to determine whether the flooring material provided an appropriate level of slip resistance for its intended public use.
Coefficient-of-friction testing is not required in every slip-and-fall investigation. Where an incident involves a spill or other temporary contamination, the analysis may instead focus on factors such as:
- the nature and extent of the contaminant;
- whether the contaminant materially reduced the available friction;
- the inspection and housekeeping procedures in place at the time;
- how long the condition may have existed before the incident;
- whether employees or the occupier knew, or reasonably should have known, about the condition;
- whether the area was promptly cleaned;
- whether appropriate warning signs or barricades were provided while the hazard remained; and
- whether the physical evidence and the reported mechanism of the incident are consistent with a slip.
Floor-safety guidance also recognizes the importance of warning signs and barricades around contaminated or otherwise hazardous floor areas. The effectiveness of these measures depends on whether pedestrians were adequately warned or prevented from entering the hazardous area.
If you are acting for a plaintiff or defendant in an indoor slip-and-fall case, contact EDA Forensics for a complimentary preliminary engineering review of the available information.
Outdoor Slip-and-Fall Incidents
Outdoor slip-and-fall incidents require a somewhat different engineering approach. In some cases, the walking-surface material itself may provide inadequate slip resistance, particularly when wet. Where the physical characteristics of the walking surface are in question, coefficient-of-friction testing can be performed in a manner similar to that used for an indoor incident, using an appropriate testing method and considering the environmental conditions relevant to the incident.
During Canadian winters, however, a more common cause of outdoor slip-and-fall incidents is the accumulation of snow and/or formation of ice on the walking surface.
In that case, the engineering analysis should consider the sequence of weather events, as well as the inspection and maintenance activities that have been performed.
Snow and ice management is an ongoing process that requires monitoring changing weather conditions, anticipating freezing conditions, performing appropriate winter maintenance operations, inspecting facilities, and responding when potentially hazardous conditions develop.
An important distinction is whether the incident occurred on a publicly maintained facility or on private premises.
For example, an incident on a municipal sidewalk or other municipal pedestrian facility may be governed by the applicable municipal legislation, regulations, maintenance standards and municipal policies. In Ontario, for example, the Minimum Maintenance Standards (O. Reg. 239/02) address matters including weather monitoring, winter patrol, snow accumulation, and ice formation on municipal facilities.
A slip-and-fall incident on private premises, such as parking lots, private walkways, commercial entrances, or condominium property, is generally considered within the applicable occupiers' liability framework, which varies by province, municipality, type of facility and circumstances of the incident.
Although the specific legal and technical requirements vary, an engineering assessment of winter maintenance commonly considers whether the party responsible for the facility took reasonable and appropriate steps to:
- Monitor the weather:
Weather monitoring should consider both current and forecast conditions that may create a risk of snow accumulation or ice formation. Monitoring the trends in pavement temperature is particularly important because ice formation depends on the condition of the walking surface and not simply the reported air temperature.
- Inspect the facility.
Appropriate inspection or patrol procedures can identify snow accumulation, ice formation, drainage problems, and localized hazardous areas before an incident occurs. The frequency and nature of inspections should be evaluated against the applicable legislation, standards, policies and circumstances.
- Remove accumulated snow.
Snow should be removed within the timeframe required by the applicable standard, policy or reasonable maintenance practice. The applicable response time may depend on the type of facility, jurisdiction, amount of accumulation and other relevant circumstances.
- Proactively prevent ice formation.
Effective winter maintenance is not limited to reacting after ice has formed. Depending on the weather and pavement conditions, preventive treatment may be needed before or during an anticipated freezing event.
- Treat ice when it forms.
If ice develops despite reasonable preventive efforts, the condition should be addressed within the applicable response period using appropriate winter-maintenance practices and materials.
- Document winter-maintenance activities.
Patrol, inspection, and maintenance records can be particularly important in reconstructing the condition of the facility. Relevant documentation may include proof of weather monitoring, recorded air and pavement temperatures, precipitation, snow depth, inspection times, snow-removal activities, the type and quantity of de-icing or traction material used, treatment times, and any hazardous areas that could not immediately be addressed.
The objective of the engineering investigation is to determine how the hazardous condition developed, whether it was reasonably foreseeable, what measures were taken to prevent or address it, whether those measures were consistent with the applicable requirements and accepted winter-maintenance practices, and whether the condition likely contributed to the occurrence of the incident.
If you are acting for a plaintiff, defendant, municipality, property owner, insurer or winter-maintenance contractor in an outdoor slip-and-fall case, contact EDA Forensics for a complimentary preliminary engineering review of the available information.
Key Factors in Slip-and-Fall Investigations
A slip-and-fall incident usually results from the interaction of several factors, including the condition of the walking surface, the surrounding environmental conditions, the maintenance and inspection practices in place, and the manner in which the pedestrian encountered the area.
A proper investigation should therefore consider the available evidence collectively rather than focusing on a single condition in isolation.
Depending on the circumstances, the investigation may include consideration of the following:
- Condition of the walking surface: The material, texture, wear, contamination, slope, drainage characteristics, and any localized deterioration or deficiency should be examined to determine whether the surface provided adequate slip resistance.
- Coefficient of friction: Where appropriate, the available static and/or dynamic coefficient of friction may be measured and compared with the criteria provided by the applicable standards and test methods.
- Weather and environmental conditions: For outdoor incidents, relevant factors may include precipitation, air temperature, pavement-temperature trends, freeze-thaw cycles, snow accumulation, ice formation, and drainage conditions.
- Inspection and maintenance practices: Records should be reviewed to determine whether the premises were inspected at appropriate intervals and whether identified hazards were addressed within a reasonable timeframe. For winter incidents, this may include weather monitoring, winter patrol, snow removal, ice prevention, and treatment activities.
- Warning and safeguarding measures: Where a hazardous condition could not be immediately eliminated, the investigation should consider whether appropriate warning signs, barricades, or other measures were used to alert pedestrians or restrict access to the affected area.
- Photographs and surveillance video: Photographs and video recordings may provide important information regarding the condition of the walking surface, the location of the incident, pedestrian movements, maintenance activities, and the presence or absence of warning devices.
- The reported mechanism of the fall: The available evidence should be examined to determine whether the person's movement is consistent with a slip and, where possible, to identify the approximate location and circumstances in which traction was lost.
- Applicable standards, guidelines, and policies: The condition of the walking surface and the actions taken by the responsible party should be evaluated against the legislation, standards, guidelines, maintenance policies, and accepted practices applicable to the location and circumstances of the incident.
- Causation: An identified deficiency does not necessarily establish that it caused the fall. The investigation should also consider whether the deficiency was likely a contributing factor in the occurrence of the incident or the resulting injury.
Considered together, these factors can help determine whether a hazardous condition existed, whether it should reasonably have been identified and addressed, whether the measures taken were appropriate, and whether the condition likely contributed to the slip-and-fall incident.
If you are involved in a slip-and-fall claim and would like an independent engineering assessment of the available evidence, contact EDA Forensics for a complimentary preliminary review.