Cartridge gravity-fed vs. user-filled eyewashes
February 5, 2010
There has been some difference of opinion about whether user-filled or cartridge gravity-fed eyewash units are easier to use and more cost effective to maintain. As the name implies, with user-filled eyewash stations, a user fills the tank with potable water and a preservative. In cartridge units, the washing fluid is supplied in a factory-sealed, disposable bag-in-a-box.
Is one better than the other? It depends on your particular situation.
Gravity-fed eyewashes have evolved quite a bit over the years. Where they were once bulky and were required to hold a tremendous amount of solution (over 17 gallons and nearly 150 lbs.) to be considered effective, 15-minute gravity-fed eyewashes have been trimmed down in size and offer a wide variety of advantages, including:
- No plumbing hassles â€” Eye relief is no longer limited to areas where plumbing is available. Gravityfed systems now bring relief to a variety of applications, from the factory and the laboratory to the outdoor worksite or remote area.
- Place it almost anywhere â€” Because gravity-fed eyewashes are not tethered to the nearest fresh water source, they can be located anywhere corrosive chemicals or hazardous particulates contaminate the air.
- ANSI-compliance â€” That all-important 15-minute flush at 0.4 gallons per minute (gpm) with tepid water is an industry-standard that is required for any gravity-fed eyewash system. Don’t accept anything less.
- Will the eyewash be used often?
- Are your employees going to use the solution to inappropriately rinse off safety glasses, their hands or anything else?
- Would the workplace jokester activate the eyewash just for the fun of it?
The design of user-filled, gravity-fed eyewashes allows for brief activation without compromising the system’s readiness. Brief activation also does not require that the entire system be refilled. As long as a minimum level of fluid is maintained to guarantee a 15-minute flush, these units will stand up to anything from weekly testing to a worker wanting a splash of water.
User-filled eyewashes generally score high on the cost-effectiveness scale. The eyewash units themselves are generally less expensive than most cartridge units, and the wash fluid is nothing more than potable water and an inexpensive bottle of preservative.
Better units are capable of a full flush using only seven gallons of solution, which makes units lighter and easier to handle. Some manufacturers offer gravity-fed eyewashes that can be mounted on a waste cart, or to a wall or flat workspace for greater versatility. Overall, newer models have become easier to fill, assemble and transport. If selecting this type of eyewash station, be sure to look for those that have a clear holding tank or fill-level window so that you can easily check fluid levels.
Where the user-filled eyewashes tend to fall short is in the amount of maintenance required. Even with clean water and preservative, the fluid in these units generally remains usable for 120 days. After that, the unit’s fluid must be changed. This can add to your maintenance staff’s already overloaded schedule.
- Are your eyewashes used rarely, if ever?
- Do you have a need for only one eyewash?
- Do you feel there would be few, if any, “accidental” activations?
- Are you willing to pay up to 25 percent more for less maintenance?
The main selling point of cartridge systems is the convenience of having little or no maintenance. Because the eyewash solution in a cartridge system is sealed at the factory, the shelf life of the eyewash solution is usually two years. If it is never activated, the cartridge-type eyewash stations can go several months without any routine maintenance. Backup cartridges also can be stored for many years as long as the expiration date has not passed.
Unfortunately, the convenience of long shelf life and low maintenance comes at a cost. First is the expense of the cartridges, which can cost $100 or more. Add to that significant shipping costs for these heavy items, and the expenses quickly add up.
Second, when the cartridge eyewash is activated, there’s no shutting it off. When the lever is pulled, the cartridge bag is pierced and all of the fluid empties. Even if the flow is stopped somehow, the solution has been compromised. When this happens, the cartridge needs to be changed, at a minimum cost of $100. If someone walking by “mistakenly” activates these stations, costs add up.
Other things to consider
Though the choice between user-filled and cartridge may be the most significant decision you’ll have to make in choosing a gravity-fed eyewash, keep in mind there are many other factors to consider, including:
- Wastewater collection â€” Where does the fluid go when the eyewash is activated? If there’s not a drain near the eyewash station, you’ll need some type of waste collection method. Check to see if the models you are considering offer waste collection options.
- Vandal resistance â€” Activating an eyewash station when it’s unnecessary isn’t the only vandalism that can occur. Experienced eyewash professionals have their own stories of cigarette butts, lunch leftovers and other debris ending up in eyewash fluid. Check to see what methods the eyewash station utilizes to protect the eyewash fluid from vandals.
- Ability to keep water tepid or freeze-protected â€” Not all eyewash stations are located in climate-controlled areas. If your eyewash station will be located in an area where temperatures can cause the eyewash solution to fall below the tepid temperature range, choose a station that features a thermostatically controlled heater to keep fluid temperature at an optimal level.