Preventing Slips, Trips, and Falls

You hear the shoe squeak, and then the hit comes; his body comes crashing to the floor so fast there is no time to catch himself. After a few moments of silence, he realizes what the fall has done: he’s got a fractured tailbone and won’t be able to easily move about for weeks.

Slips, trips, and falls are the second most frequent cause of personal injury to the head, back, and body. They can cause head injuries, cuts, bruises, fractures, and more. According to the National Floor Safety Institute, “slips and falls are the leading cause of workers’ compensation claims and are the leading cause of occupational injury for people 55 and older.”

It is reasons like these that floor slip resistance tests are a lifesaver to both the workers and the company. Depending on the situation, some floors are tested before installation for the coefficient of friction, or plausibility of slipping, and others aren’t done until after installation when a slip has already occurred.

 

Before Installation

As a business owner looking to build or remodel your own office or warehouse, you can send in flooring samples to places like Safety Direct America for a slip resistance test before you choose to install it at your new place. There are a number of ways we can do this for you:

  • BOT-3000E Digital Tribometerthis is for wet surfaces, or surfaces that are likely to become wet. It can measure both the static and dynamic coefficient for both wet and dry surfaces.
  • The Pendulum Method for Pedestrian Slip Resistance Testingthis is the most accepted form of pedestrian slip resistance testing worldwide.
  • SlipAlert - It measures the slipperiness of a floor and has been specifically designed to simulate a real slip and to correlate with the TRL Pendulum.
  • Tortus 3 – this is a friction slider mounted on a leaf spring that moves forward at a constant velocity and is able to read friction via a strain gauge.

Safety Direct America can help you decide which method is best for your situation.

 

After Installation

If you take over an existing building to start a business, you might want to get your own slip resistance testing done before bringing in employees and beginning work. Many companies are willing to come out on site and do similar testing that they would in lab right there on your office building floors. If your floors don’t meet the standard, there are a few things you can do to help keep your employees from slipping:

  • Non-Slip 21 – this is a transparent, non-abrasive, anti-slip treatment put on by a professional. It is great for decorative, colored, or nice looking floors when you don’t want the treatment to be seen. It works great for things like granite, ceramic tiles, limestone, concrete, linoleum, and more!
  • Non-Skid Tapes – these are self-adhesive grip tapes you can place anywhere you’d like. They help keep people from slipping in high foot-traffic areas.
  • DIY Paint-On Abrasive Anti-Slip Coatings - apply similar to any other paint. Good for use in places like hospitals, showers, walkways, restrooms, and more.

So don’t let the worker’s compensation requests pile up from slips and falls: get a slip resistance test done and ensure your flooring is ready for high foot traffic without slips!

 

Protect Your Shoppers During the Holiday Craze

For many the holiday shopping season officially begins with the infamous Black Friday sales. Retailers across the country are going to be promoting their absolute best deals in the hopes of breaking their own sales records from years past. Originally, stores would open earlier than normal to the waves of bargain shoppers just itching to get the best deals. It wasn’t long until stores began their Black Friday sales at the stroke of midnight. In more recent years, many retailers have opened their doors on Thanksgiving night to those who have already enjoyed their turkey and are ready to spend their money. There have been many articles about how Black Friday is slowly taking over Thanksgiving, essentially ruining the holiday for those who get stuck having to face the masses for hours on end. Regardless on how you feel about Black Friday, the truth is that the stores are packed with people who are likely to bring in the snow and rain that may be falling outside, and that only means one thing: slippery floors.

wet and slippery floor

Just turn on the news that weekend and you are sure to hear reports of people slipping and falling while trying to race in the store. In previous years some of these reports have even ended in death with someone getting trampled by rampaging shoppers. Black Friday is only the beginning. While most days following the biggest shopping day of the year are no where as chaotic, most stores see in increase in foot traffic through the month of December. If it’s been raining or snowing outside, then the chances are pretty high that the holiday shoppers will be tracking in the wetness onto your store’s floors. This will inevitably increase the risk of shoppers slipping and falling, potentially really injuring themselves while holding your store and company responsible.

Retailers want to ensure their customers’ satisfaction. Preventing slipping accidents is a great way to protect your customers so that they can go on shopping without accident or injury. Of course, it can be difficult to always tend to the constant wet floors, especially on a busy sales day, but Safety Direct America can help. At Safety Direct America you can have your floors tested with our Slip Resistance Testing to determine how safe they are when wet. We also sell DIY Anti-Slip Products, including a variety of anti-slip grip tapes that you can apply yourself in the areas that need it the most. Take precaution this holiday season and ensure your customers’ safety with Safety Direct America.

 

Do All Pedestrian Ramps Need the Same Coefficient of Friction?

The minimum safety standard for coefficient of friction for a pedestrian ramp should depend on the angle of the ramp and the weight of the separate load (shopping cart, wheelchair, gurney, etc.), if any, the pedestrian is controlling. However, that’s not how American safety standards are writteSlip at top 17-2n.

In the USA, traditionally safety standards for slip resistance (or coefficient of friction, COF) of pedestrian ramps have had only one minimum value (e.g. 0.80 or 0.46, depending on the standard and whether it specified static or dynamic friction). This applied regardless of the slope of the ramp or what the ramp was used for. This is in the interest of simplicity, but it is contrary to common sense and the laws of physics.

A “ramp” as defined by the Americans with Disabilities Act (ADA) can vary from a shallow slope of 1:20 (2.86 degrees) to a steeper 1:8 (7.12 degrees). The latter of course needs a higher coefficient of friction to be safe. Also, if the ramp is to be used for loads not carried by the feet, it needs higher friction. That’s because under the definition of coefficient of friction, the friction force is proportional to the weight on the feet. That is, a 220-pound person gets twice as much friction as a 110-pound person. If in addition there’s weight not borne by the feet — for instance, when a 100-pound nurse is pushing a wheelchair and patient totaling 250 pounds — the COF needs to be higher to prevent slipping.

A paper by Sotter et al. in the Proceedings of the XIX Annual International Occupational Ergonomics and Safety Conference analyzes the static coefficient of friction needed for safety on a ramp. The graph below shows the results when the pushing is parallel to the surface of the ramp. The COF needed for a level floor is assumed to be 0.60.

Screen shot 2014-11-24 at 8.01.10 AM

Example: for the 100-pound nurse pushing a 250-pound load on a 5.71-degree ramp (yellow line) the weight ratio is 2.5, and so the required COF is 0.94.

The photo below shows hospital laundry going downslope and being controlled by a near-horizontal force. When the pedestrian is exerting a force upward, e.g. pulling a pallet jack, a lower COF will suffice because some of the weight of the load is transferred to the pedestrian’s feet by the upward pull. For more details, please see the paper.

Safety Direct America has lots of choices for improving the wet and dry slip resistance of ramps: coatings, tapes, and chemical treatment. For details contact George Sotter at 1-800-988-6721.

Laundry down 8b

 

 

Slip-and-fall Fraud — Some Clues

How can you avoid slip-and-fall scams on your property? First and foremost, eliminate hazards. The initial step is testing floor slip resistance before a fall is reported. Failing that, pay attention when someone reports a slip, even if it didn’t lead to a fall or injury. That report put you on notice — you can’t truthfully pretend not to know there was a hazard. Make sure you can’t credibly be accused of negligence that led to the accident. Scammers love to see negligence (“failure to act reasonably under the circumstances”) because it makes their job easier.

Complying with the minimum requirements of the building code for slip resistance might not be a defense. The code says you must consider many other factors — sixteen, in fact.

There must be a link between the hazard and the fall, known as causation. However, any competent con artist should be able to set up that match by giving thought to the staging of the accident.

If you could have prevented or eliminated the hazard at reasonable cost, you had a duty to do that. Slip-and-fall accidents are not always trivial — damages can exceed a million dollars for one accident. Hoping that you’d be lucky might not be an effective defense.

There are many ways of eliminating slip hazards, for small areas and large.

Clues

Location. The location for a scam is likely to be one where there are no witnesses (other than accomplices). Scammers should be aware that there is video surveillance in many public areas, but make sure to preserve the record if there is one.

Victim. Is the “victim” a solid citizen or a transient, or an unlucky soul with numerous previous claims?

Evidence. The spill that caused the fall may have been planted by the victim or an accomplice. Broken eyeglasses, cameras, phones, etc. may have already been broken when they came onto the premises. Blood might have been brought in a syringe for the occasion.

Damages. Soft tissue injuries are hard to prove or disprove, but X-rays of skeletal damage may have been made days or years before the incident on your premises. Maybe the injury happened in a bar fight last Saturday night, or on the stairs at home, or when the “victim” ran her car into a tree.

Offer to settle. A claimant who is too anxious to “get this over with” and get on with his vacation should be aware that real slip-and-fall injury effects may last for years.

Lawyers, doctors and chiropractors. These professionals may be willing or unwitting accomplices. However, many of the crooked ones prefer to spend their time on more-lucrative auto accident scams.

Workers not covered by your workers’ comp. Your business property may be mostly used by your loyal employees, but don’t forget that delivery people, subcontractors, and sales representatives may have claims that your workers’ comp, and theirs (once their carrier finds out you’re responsible), won’t cover. Make sure that you don’t have hazards that imperil them and thus invite litigation.

For more detail on slip-and-fall fraud see Chapter 15 of the book STOP Slip and Fall Accidents! For help in eliminating your hazards and documenting the safety of your floors, contact Dr. George Sotter, state-registered Professional Engineer, at Safety Direct America: 1-800-677-9821.

Does ANSI Tile Spec A137.1 help protect you from liability for slipping accidents?

If you specify or buy flooring based on a minimum wet dynamic coefficient of friction of 0.42, you may be vulnerable to charges of negligence if a slipping injury occurs on that floor. Here we tell you why, and how to avoid the situation.

American National Standards Institute (ANSI) issued its standard A137.1, “Specifications for Ceramic Tile,” in 2012. The standard, also known as the AcuTest, is incorporated by reference in the 2012 International Building Code, which is used throughout the United States and in several other countries. The code specifies a minimum wet dynamic coefficient of friction (DCOF) of 0.42 “for tiles in level interior spaces expected to be walked upon wet.” The test uses a hard rubber slider to simulate the heel of a dress shoe.

Does this mean that a tile is safe if it has a wet DCOF of 0.42? Absolutely not.

The standard goes on to state that, “Tiles with a DCOF of 0.42 or greater are not necessarily suitable for all projects. The specifier shall determine tiles appropriate for specific project conditions, considering by way of example, but not in limitation,

  • “type of use,
  • traffic,
  • expected contaminants,
  • expected maintenance,
  • expected wear, and
  • manufacturers’ guidelines and recommendations.”

Tile Council of North America (TCNA) has added to this list. They state that the possibility of a slip may be affected by

  • The material of the shoe sole and its degree of wear
  • The speed and length of stride at the time of a slip
  • The physical and mental condition of the individual at the time of a slip
  • Whether the floor is flat or inclined
  • How the surface is used
  • How the tile is structured
  • How drainage takes place if liquids are involved

ANSI and TCNA give no guidance as to how all of these items should factor into a higher DCOF or slip resistance, if needed, and most flooring manufacturers give no slip resistance guidelines or recommendations whatsoever. The TCNA goes on to state that through their own extensive research, the ANSI A137.1 test method results have been shown to closely correlate to the now-withdrawn ASTM C1028 test method that has been wreaking havoc across the United States for decades since many tiles can “pass” the C1028 test while still being extremely slippery when wet. C1028 was withdrawn by the ASTM in 2014 since it was a very bad test that was basically responsible for thousands upon thousands of needless slip and fall accidents across the country annually by spreading misinformation about the actual real-world slip resistance of various flooring materials.

Do you duly consider all of the above 16 listed items when you specify, buy or sell flooring? (Does anybody?) Certainly these published lists can expose people on the buying side, and perhaps in the whole chain of supply as well, to accusations of negligence. And negligence is something that plaintiff lawyers love to see when their client has had an expensive and debilitating injury.

How can people do a better job for themselves and the public than just looking for a minimum DCOF of 0.42? How much higher should it be? Should it be 0.50, 0.60, 0.80? (Just as a point of reference, American and European standards require that a basketball court floor have a dry coefficient of friction of 0.97 or higher.)

Help Arrives from Down Under

Fortunately there’s helpful and proven guidance for a large number of specific situations, and it’s described in a recent entry on this blog. Briefly, a minimum wet Pendulum Test Value (PTV) for the flooring is used as a specification for a given situation. For instance, a hotel bathroom should have a minimum wet PTV of 20 (measured using a soft rubber slider to simulate bare feet or soft shoe bottoms). Restrooms in offices and shopping centers, where people might be moving faster, should have a PTV of 35 or higher. That higher minimum also goes for bathrooms in hospitals and aged care facilities, because the people involved there are at high risk.

Communal shower rooms should have a minimum wet PTV of 40, and swimming pool ramps and stairs leading into water should have at least 45.

Those are typically barefoot areas, but there are also many standards for indoor areas where shoes are worn: building entries (PTV of 35 or higher), commercial kitchens (45), balconies, verandas, roof decks, cold storage walk-in freezers (40), etc. There are safety standards for other outdoor areas as well. (Remember, ANSI A137.1 only applies to indoors.)

Does this system make more sense than a one-size-fits-all minimum such as 0.42 after which the customer must make important decisions based on no advice or data whatsoever? The Australian standard we refer to is a minor revision of one that’s been in effect since 1999. We think that’s something to hang your hat on when you try to prevent injuries — or to defend yourself in court. The pendulum test instrument used in this situation-specific test has been testing floors involved in actual real-world slip and fall accidents in the United Kingdom since the 1950s, so the research into these safety standards are unparalleled with any other instrument or test method. It’s used in at least 49 nations on five continents.

The ANSI A137.1 DCOF of 0.42 is a very easy criterion for a tile to meet, and so the “specific project conditions” listed by ANSI and TCNA (see above) would be very important. A tile with wet DCOF of only 0.42 from this test could be extremely hazardous in many situations.

ANSI has a better test for assessing floor slip resistance: ANSI B101.3. It’s very similar to A137.1 but has twice the wetting agent in the wetting water used for the test. This usually results in a lower DCOF for the same tile. The same instrument, the BOT-3000E, is used for both tests. (ANSI B101.1, static coefficient of friction, should not be used for assessing safety.) ANSI B101.3 is backed up by extensive laboratory research on actual human traction, whereas ANSI A137.1 is not.

Safety Direct America conducts ANSI B101.3, B101.1, A137.1, and pendulum tests in the laboratory and in the field, using both hard and soft rubber sliders as appropriate. We do this floor slip resistance testing work for commercial buildings, major cruise ship companies, tile vendors, attorneys, and many others. For more information see our web site or contact Dr. George Sotter at 1-800-916-2193.

Head Off Litigation with Third-Party Confidential Periodic Floor Slip Resistance Testing

Slips and falls can result from a wide range of causes. To avoid litigation your commercial property needs to be immune to claims that your negligence caused an injury.

The most effective way of doing this is to have Safety Direct America monitor your floors for slip resistance, and have your floor care personnel take action to eliminate any potential hazards that might be detected. Our written, professional-engineer-stamped confidential reports and recommendations in your file can have an almost magical effect in preventing claims of negligence against you for slip/fall injuries. We are certified by the City of Los Angeles for testing floor friction, and this is one of the very few government agencies in the United States that grants such certification. We have conducted walkway skid testing for the City of San Francisco and the City of Palo Alto, as well as other municipal governments and many commercial companies.

The Benefits. Our walkway traction auditing (slip resistance monitoring) programs include these potential benefits:

  •             Effective monitoring of your floor-care crew’s results
  •             Detection of changes occurring due to crew personnel turnover
  •             Cost-effective floor care decisions by you based on accurate, reliable data
  •             Easy-to-read reports documenting the status of your floors
  •             Floor-care vendor contractual accountability
  •             Compliance with the Americans with Disabilities Act (ADA) for slip resistance
  •             Compliance with OSHA slip resistance requirements
  •             Discharge of your duty to protect visitors to your property
  •             Improved employee efficiency and morale
  •             Fewer accidents
  •             Few (or no) frivolous or fraudulent claims
  •             Lower insurance premiums and deductibles payouts
  •             Less time and effort spent on litigation, including lawsuits

None of our monitoring clients has ever needed us to testify, but if it’s necessary we have experienced expert witnesses that can help prepare and present your case. The important thing is to establish a monitoring history and positive actions (e.g. minor changes in floor maintenance procedures) to prove your due diligence in preventing slips.

Test Program. If a floor area normally is dry in use it may be sufficient to have us only test it dry. For areas that get wet, we would monitor both dry and wet slip resistance to head off potential problems under either condition. For dry testing, static coefficient of friction (SCOF) is usually sufficient. For wet testing, dynamic coefficient of friction (DCOF) is needed. We can conduct both tests in a matter of seconds using the same instrument, the BOT-3000E that’s used for American National Standards Institute (ANSI) safety standards B101.1 (static COF) and A137.1 or B101.3 (dynamic COF).

The obsolete ASTM C1028 SCOF test was withdrawn by ASTM in 2014, so don’t rely on this test or on ASM 825A [not ASTM] test results. The latter is a static test similar to ASTM C1028 but is not, and never has been, approved by any recognized standard-setting organization. When the floor is wet these two test methods are not useful for predicting pedestrian slip resistance and will have little or no credibility in your defense. Various other floor skid test methods are discussed in our online video.

In your floor monitoring program, some high-traffic areas should be monitored at least quarterly. Other areas might be audited only annually.

Contributing factors to slipping accidents include the person, footwear, activity, floor surface, or environment (e.g. restaurant, car wash, etc.). Make sure your floor surface — particularly, your negligence — is not to blame by calling George Sotter at Safety Direct America, 800-677-9821, today to discuss starting a traction auditing program for you.

Improving the World’s Most Sophisticated Floor Slip-Resistance Safety Standards

In June’s post we discussed situation-specific slip resistance safety standards, which reflect the use or function of a floor and the friction (coefficient of friction) demands placed on it. Many U.S. floor friction standards are “one size fits all” — for instance, a wet dynamic coefficient of friction (DCOF) of 0.43 is considered adequate for any situation where the (level) floor gets wet. Traditionally, using the ASTM C 1028 method of assessing a floor’s slip risk, a 0.60 static coefficient of friction (SCOF) was considered adequate. (However, ASTM has officially withdrawn that test method, and so the 0.60 safety criterion is now a thing of the past. It no longer has any relevance whatsoever.)

Would you expect a posh hotel lobby to have the same demand for traction as a basketball court? The higher speeds and rapid acceleration and stopping demands of basketball call for a much higher, but still limited, amount of friction. This comparison is just one example of why different slip test safety standards are appropriate for different floor areas.

After 15 years of experience with the sophisticated safety standards mentioned above, Standards Australia on June 16, 2014 issued an improved version (preview: HB_198-2014). Wet slip resistance (or the dynamic coefficient of friction), as before, is tested using the British pendulum instrument. Either soft or hard rubber sliders can be used to simulate dress shoes (“Four S” hard rubber) or athletic shoes and bare feet (“TRL” soft rubber). Only one of the safety criteria (either hard or soft rubber) need be satisfied to comply with the slip test safety standard.

The new safety standards are summarized in Table 1 below. For example, Line 1 shows that steep outdoor ramps should have a wet Pendulum Test Value (PTV, which is also sometimes called BPN for Brithish Pendulum Number), tested with soft rubber, of at least 45. On the other hand, for normally dry areas in hotels, elevator lobbies and kindergartens, a wet PTV of 12 (hard rubber) is adequate. (Remember that dry areas can get contaminated with dust and with tracked-in grease from a parking area or kitchen. Wet slip resistance can help prevent slips in these cases.)

Table 1. Standards Australia slip resistance minimums

Aus Jun 2014 std

Swimming pool decks, preferably tested with soft rubber (to simulate bare feet), should have a minimum PTV of 40, but for hospital and aged care facility bathrooms a PTV of 35 is considered adequate.

The Australian standards also quote requirements for dry and wet stairs and landings, which were already specified in the National Construction Code there. Dry stairs need a wet PTV of 35 or higher, while even more stringent standards apply to wet stairs.

We at Safety Direct America conduct both laboratory British pendulum skid tests, and testing at your location on your existing floors. We also test using the ANSI A137.1 ceramic tile slip resistance test procedure and safety standards specified by the 2012 International Building Code (IBC), using the BOT-3000E digital tribometer. In many cases the IBC safety standard will be easier to meet than the Australian standard. The IBC standard is very permissive in some circumstances, making it easier to sell slippery flooring. The Australian standards are not as vendor-friendly and so are a much more reliable method of preventing accidents, injuries, and litigation.

Regarding the basketball court mentioned above, it’s not included in the Australian standards. An ASTM standard and a European standard specify a PTV between 80 and 110, with no part of the court deviating from the mean by more than 4 units. This applies to dry testing if the court is kept dry in use. For safety, most indoor basketball courts (being very smooth and glossy) must be kept dry by assiduously wiping up sweat deposited when players fall (or get knocked down), which they very frequently do.

Three Common Fallacies about Floor Slip Resistance

There are three widely-held misconceptions about pedestrian slip resistance. If you’re aware of them it can help you avoid a nasty, expensive, and possibly life-changing surprise.

Fallacy #1: “If a floor has a matte finish — that is, it’s not “shiny” —, it won’t be slippery when wet.” Truth is, many floors that have a matte finish are quite slippery when wet. Worse yet, because of its appearance many pedestrians will assume the floor is not slippery and will not take precautions — like making smaller strides and walking more slowly and cautiously — like they might on a glossy floor when it’s wet or their shoe bottoms are wet. This can increase the possibility of slip and fall accidents on these types of matte surfaces.

To avoid accidents on a floor that can get wet or otherwise lubricated (e.g. by deep fryer or broiler fat settled out of the air), have a sample of the flooring laboratory-tested for slip resistance by Safety Direct America before you make a purchase commitment. We can advise you as to what slip test safety standard is appropriate for a given situation: restroom, entrance lobby, pool deck, kitchen, bathtub, sidewalk, ramp, public shower, etc.

Fallacy #2: “If a flooring sample feels slip-resistant to my shoe when dry, it will also be slip-resistant when wet”. Nothing could be farther from the truth. Many smooth, glossy floors have excellent slip resistance when dry, but are treacherously slippery when wet. Again, laboratory floor slip testing by Safety Direct America can give you confidence that you’re buying the right flooring for the job. Sadly, many people have swimming pool decks installed that are slippery when wet! Children (and adults) running or even walking normally on such a deck are at risk of very serious injuries. At best, knowing that the pool deck is treacherous can spoil the fun that is the pool’s reason for being.

Fallacy #3: “If flooring has good wet slip resistance when it’s purchased, it will preserve that slip resistance forever.” It is quite possible to buy flooring that has good wet slip resistance, given honest test results for friction and an appropriate safety standard applied to those results. However, in a situation with high foot traffic that slip resistance might only last a few weeks or months! McDonalds Restaurants found that out long ago and after years of research came up with the Sustainable Slip Resistance test to check the tile after wear simulating traffic in a busy restaurant. They adopted it as a new flooring specification, and we adopted their test method for the benefit of our clients.

Sustainable Slip Resistance (SSR) testing by Safety Direct America can help you assess whether the flooring you’re about to install, possibly at great expense, is likely to keep its wet slip resistance for more than a short time. With the proper information on the slip resistance of your floors, or the flooring you are going to possibly install in a new project or renovation, you can avoid costly lawsuits, injuries, and the replacing of the flooring after the official opening of the building, which could mean your building is shut down for several days or weeks leading to possibly millions of dollars in losses for the businesses in your building.

Situation-Specific Floor Slip Resistance Testing Standards

In the USA, pedestrian slip resistance standards for flooring have traditionally been pass-fail. For instance, a coefficient of friction (COF) of 0.60 might be considered “safe” but 0.59 was “not safe.” This applied to any situation provided the floor was level.

Recently the American National Standards Institute (ANSI) has published some standards that are a bit more detailed. Depending on the value of the dynamic coefficient of friction there is a “lower probability of slipping” potential, an “increased probability …” and a “higher probability.” For the “increased probability” regime, action is recommended, depending on the tile or other flooring’s intended use, to reduce risk.

Under either of these systems there’s no consideration of what the use of the floor is. For example, a 30th floor office building elevator lobby would have the same slip resistance safety standard as a swimming pool deck. An indoor shopping mall in sunny Las Vegas could have the same safety standard as an outdoor walkway in rainy New Orleans. This could put too much restriction on flooring choice in one situation, and/or an insufficient safety standard for another.

Australia and New Zealand, which are decades ahead of the United States in the serious study of slip and fall accident prevention, has established some slip testing standards based on the situation and based partly on some earlier standards established in Germany. As racing fans in Britain say, one should choose “the right horse for the course.” The Australia/New Zealand standards were established in 1999 (Standards Australia HB 197–1999 and ASNZS 4586:1999) and slightly expanded in 2013.

The standards are based on wet slip resistance testing using the pendulum tester, which yields a Pendulum Test Value, PTV. The testing can use either a hard rubber slider or a soft rubber slider (or both). Hard rubber simulates the bottoms of dress shoes, while soft rubber is more representative of bare feet or athletic shoes. The detailed properties of the rubbers are specified by the standard. (There is no correlation between Pendulum Test Values and other tribometer readings, or in general between other tribometer types; therefore the pendulum test must be used to implement these floor slip test standards.)

High PTV corresponds to high wet slip resistance, or a very low contribution of the floor surface to the risk of slipping when wet. Table 1 below shows suggested minimum wet PTV’s for various situations. These can be helpful to building owners who want to prevent slipping injuries and the human and financial costs they incur. “Accessible” in the table refers to areas intended to be accessible to the disabled.

Floor Slip Resistance Testing Standard

Table 1. Slip resistance test value suggestions for various situations

Table 1 shows that six “dry in use” of the 23 categories have no requirement for wet slip resistance. However, these areas should be kept free of grease, dust, tracked-in water, and spills. Generally, at least 10–15 feet of absorbent matting is needed to dry shoe bottoms before reaching the hard floor when it’s wet outside. Ropes along the edges of the mat can keep people from straying off the mat before their soles are dry. A dry mop, washed first to remove any oil, is needed to take up water dripping from raincoats. Umbrella bags on a stand at the entrance can help control drips.

The highest slip resistance in Table 1 is specified for outdoor ramps, and for swimming pool ramps and stairs that lead into the water.

Safety Direct America conducts pendulum testing both in the laboratory and in the field. We also offer the Sustainable Slip Resistance test that is specified by McDonalds Restaurants for assessing how well wet floor slip resistance will hold up after heavy wear from foot traffic.

To follow the 2012 International Building Code, ceramic tiles that are used indoors under wet conditions should also conform to ANSI Standard A137.1 wet dynamic coefficient of friction requirements. Testing uses the BOT-3000E digital tribometer. This instrument, lower in speed than the pendulum, is generally not considered suitable for testing outdoor flooring.

By using appropriate floor slip resistance testing methods and standards, building owners, managers, designers and architects can make intelligent choices in selecting flooring appropriate for each use in order to help minimize risk of slip and fall accidents.

Wet static coefficient of friction testing (SCOF) as described by the misleading ASTM C1028, is no longer considered a valid or reliable slip test method and it was officially withdrawn by ASTM in 2014. Americans caring for buildings and floors must now catch up with the slip resistance standards that have been in use for years in other countries (such as the pendulum test standards) and the new American dynamic COF tests like ANSI B101.3 and ANSI A137.1 in order to help end the epidemic of slip and fall injuries and lawsuits here in the USA. The tools are in place — all that remains is to use them.

Variables that Affect Slip Resistance of Polished Concrete

At the 6th Annual International Concrete Polishing & Staining Conference in Atlanta in September 2013, a panel discussion was organized and chaired by Ken Fisher of Nu-Safe. On the panel were the manufacturer of the BOT-3000E tribometer (floor slip resistance test meter); an Orlando attorney for large international property owners; and slip and fall prevention engineer Dr. George Sotter of Safety Direct America.

Dr. Sotter summarized some of the variables affecting slip resistance of polished concrete. When it’s clean and dry, he said, it’s normally not slippery.  When wet, it might be.

Topical sealers can be a problem. Sotter said, “Think about how an ice rink is made. A liquid, water, is spread on a surface, then solidified into ice. When water is put on top of the ice, that’s a very slippery situation. A topical sealer is also a liquid that solidifies, and with water or other liquid on top it can be treacherous.” Penetrating sealers can be OK if applied properly — the surface roughness is maintained. This means carefully removing the sealer from the surface before it dries. Coatings/sealers with aggregates (such as SolidStepCote from Safety Direct America) can also provide good slip resistance.

Micro-roughness of the surface can be important and is easily measured, but is not a fool-proof indicator of wet slip resistance; a friction test (or coefficient of friction test) is still needed. Too-rough textures may be harder to clean. Concrete finishes that are honed with a finer grit provide lower wet slip resistance, but safe surfaces can be obtained with a surface roughness fine enough not to detract from the appearance. Color pigments don’t necessarily affect wet slip resistance.

Autoscrubbers (scrubbing machines that use vacuum to pick up the dirty water) are usually best for cleaning — a mop is suitable only for smooth floors without greasy/oily deposits. (A very soft autoscrubber brush, like a carpet brush, cleans effectively with minimal effect on slip resistance. Pads — even nonabrasive ones — tend to pick up dirt and may scar the surface.) A monthly high-pressure cleaning can be helpful. Sweeping may spread contaminants and be ineffective on rougher floors. For applications such as shopping malls, cleaning should be done nightly, but in some other circumstances a weekly cleaning is sufficient.

Even a few layers of floor polish can significantly reduce the wet slip resistance.

The most important step in creating a polished concrete floor that’s slip-resistant is to test from the start of the polishing process. The test must include sealer and polish if they are to be used. Better to find out on the first 10 square feet that there’s a potential problem rather than after the whole job is done! Continue testing as the polishing process proceeds; variable slip resistance is considered a hazard. Since concrete batches can vary, the polishing is an in-situ process, and humans are involved, variation can easily happen.

Safety Direct America (SDA) can help by conducting slip resistance tests on-site. The best wet tests for indoor surfaces use the BOT-3000E digital tribometer, which is also available for purchase (at discounted prices) from Safety Direct America. For a level indoor floor, a dynamic coefficient of friction of 0.43 or higher using the ANSI B101.3 test procedure is a reliable indicator. Values as low as 0.30 may be acceptable with periodic monitoring, but consider traction-enhancing products and practices depending on use of the area. Ramps may require increased roughness. Static friction tests are not reliable indicators of safety and can be very deceptive. For outdoor surfaces, where pedestrians may sometimes run (especially when it starts to rain), the pendulum test is preferred because its slider (test foot) moves at higher speed than the slider of the BOT-3000E.

A BOT-3000E slip test described in ANSI A137.1 is by reference part of the 2012 International Building Code, applying to ceramic tile. This test, championed by the ceramic tile industry, often gives a higher DCOF than ANSI B101.3 because less wetting agent is used in the water for the test. However, “Tiles with a wet DCOF of 0.42 are not necessarily suitable for all projects. The specifier shall determine tiles for specific project conditions.” Dry DCOF measurements made using the BOT-3000E may also be of interest. Safety Direct America can help with recommendations of slip resistance for specific situations: food courts, restrooms, sports stadiums, outdoor surfaces, etc.

Wet slip resistance may not be important in areas that can consistently be kept dry. Injury claims might still be filed, and it’s helpful to have dry test results showing that the floor is not a safety problem when clean and dry. However, it’s crucial to remember that surfaces that have excellent dry slip resistance are often very slippery when wet. Dry slip resistance is not an indicator of wet slip resistance.

For external surfaces an 80–100 grit finish with a penetrating sealer should satisfy slip resistance requirements.

Whatever the surface, having documented test results for slip resistance at the end of an installation is very important for the protection of all involved. Regular monitoring is also recommended by American National Standards Institute ANSI B101.3. Quarterly monitoring by a third party is popular because it roughly ties in with the turnover rate of floor maintenance personnel and/or contracts in many buildings. However, semi-annual or even annual monitoring is better than no monitoring at all. Monitoring reports can be highly cost-effective — they have been shown many times to be very discouraging to plaintiff attorneys.

Safety Direct America can provide initial floor slip resistance testing, monitoring and test reports, signed and sealed by a registered Professional Engineer. Contact George Sotter, P.E. of SDA at 800-988-6721 for more information on floor slip resistance testing for your property, or for slip tests in our lab for the flooring you plan to use in a new project.