School Science Lab Design
First, what are the space requirements for a safe science laboratory?
What is the maximum number of students you should have in your science laboratory? How much lab space should be available for each science student?
These are two of the most frequently asked questions about science lab design. The frequency of these questions points out the safety consciousness of today's science teacher. Here are some guidelines on how to help solve the problem of overcrowding in the science laboratory. We hope you and your administration will evaluate and adopt these guidelines in an effort to provide a safer working and improved learning environment for teachers and students.
Many schools are experiencing budget problems. Any and all solutions to reduce school spending are being considered. One of the many solutions school administrators are considering to help "ease" budget problems is to increase the number of students in each class. Increasing class size not only delays the need to hire additional teaching staff, but also postpones the need to provide additional classroom space. For the science laboratory, this solution creates major problems.
Science teachers sense that overcrowded conditions in their science laboratories contribute to lab accidents. Their safety sense has not failed them! Overcrowding in the science laboratory is a major contributing factor to the safety problems school science departments face today.
While we are concerned about the safety of the students, let's not forget that overcrowded conditions in the science laboratory also present an unsafe working environment for the science teacher as an employee of the school. Most science laboratories are designed to accommodate 24 students, an accepted professional standard. When class sizes are larger than 24 students, it becomes very difficult for the science teacher to safely handle, transport and use laboratory chemicals and equipment. Increased class size puts "at risk" the health and safety of the science teacher.
Though student safety in the science laboratory is a major reason for limiting class size, another consideration is the ability to provide quality laboratory instruction. Many laboratory experiences require a high degree of student-teacher interaction. The fewer students there are in a laboratory, the greater the opportunity for students to ask questions and for teachers to clarify procedures and encourage the development of reasoning skills.
Science teachers report that their classes are being held in rooms that were never designed for the teaching of science. Other teachers have had to discontinue the number of hands-on labs they do each year because they now have less preparation and setup time.
Overcrowding also increases discipline problems. In a lab situation, discipline problems only result in "unsafe" conditions.
Class sizes in some schools have grown so large that teachers no longer run hands-on labs because of unsafe conditions caused by overcrowding. Some teachers have concluded that the risks involved in conducting labs in overcrowded laboratories are greater than the benefits the lab experiences provide. How many science laboratories are considered "safe" because the lab work has been removed from the curriculum?
The type of layout you ultimately select depends on many factors. No one design works well for all sciences. Here are a few thoughts on lab layout.
The lab layout you select will be used for the next 25 to 30 years. Think about how much science has changed from the 1960s to today. You need to think about what science will look like in the year 2020. What influences will technology and computers have on the way we teach science? How will integrated science affect the lab space you're designing? Will team teaching be a common method of teaching? The demands to have more hands-on science will continue to grow. How will this growth affect the lab that you're designing?
The questions can go on and on. All we ask is that you think about what science will look like in 20 to 25 years. Now that we've started you thinking about the future, here are a few recommendations.
* Design a lab space that can be used for all sciences. Flexibility in design is absolutely critical.
* Computers and the use of technology will continue to grow. Make sure you have space and easy access to run additional cabling in future years.
* Design a lab where the teacher can see all the students at work simply by standing in one place and turning around. Easy access to all students is critical.
* Try to keep the lab and classroom separated. Do not design a lab that uses perimeter lab stations with desks stuck in the middle. While this is the most common lab design, it is also the least creative and causes all kinds of problems for both teachers and students.
* Be creative in your design. Visit lots of schools and see what unique designs they have developed. Take your camera to remember the ideas. Remember creative does not have to mean expensive.
* Select an architect who has designed and helped to build school science labs. Experience in building and designing science labs will save you both time and money.
* Be active in the design process. Know your priorities and communicate them to all involved.
* Be prepared. If you are planning on designing a science lab two years from now, you should start your planning now. Having time to plan and think about the many decisions you will be making is the single most important ingredient to successful designing of a science lab.
Having "great" ventilation in the science classroom laboratory must be your No. 1 priority when designing a lab. The purpose of the OSHA Laboratory Standard is to protect employees and students from being overexposed to hazardous laboratory chemicals. The key to complying with the OSHA Laboratory Standard is to have good laboratory ventilation.
The goal you should set is to have a complete air change in five minutes. You need a fan which can move and exchange almost 3,000 feet of air in just one minute.
Consult the HVAC engineer working on your project to find out how this can best be done. The cheapest option is to simply install a purge fan in a wall. For less than $1,000 (fan and installation), you can have great ventilation.
Three different types of tabletops are available for science labs. Select the tabletop which best fits your intended use and needs.
Plastic laminate is economically priced top for use in general science classes. It wears exceptionally well under normal use. It has superior resistance to scratching with limited resistance to high temperatures, organics, and concentrated acids and bases.
ChemGuard is specifically designed for the science laboratory. It is an excellent alternative to the more expensive epoxy resin tops. It has excellent resistance to scratching and heat. ChemGuard should not be subjected to open flames or temperatures exceeding 275 degrees F.
Epoxy resin is your best choice for a laboratory tabletop. Epoxy resin has excellent resistance to chemicals, heat and scratching. The surface is simple to clean and, if maintained properly, will look "brand new" for years.
This article is courtesy of Flinn Scientific, www.flinnsci.com.
©2007, Flinn Scientific, Inc. All Rights Reserved. Reproduced for one-time use with permission from Flinn Scientific, Inc., Batavia, Illinois, U.S.A. No part of this material may be reproduced or transmitted in any form or by any means, electronic or mechanical, including, but not limited to photocopy, recording, or any information storage and retrieval system, without permission in writing from Flinn Scientific, Inc.
Undercounter Dilution/Neutralization Tanks
By Len Weiss
One of the last things you might think about in a school laboratory is the humble dilution/neutralization tank neatly tucked from view under a counter. “Out of sight, out of mind,” as the old saying goes. That could be an inconvenient mistake. Dilution tanks typically are concealed from sight, but don’t make the mistake of neglecting them. With heavy use, such as in a school laboratory, tanks can quickly become fouled with caustic chemicals, which can do harm to municipal sewer lines and the environment.
State and Federal environmental regulations do not give K-12 schools a pass when they fail to comply with regulations regarding asbestos, other hazardous materials, chemical handling and other rules. These schools are often caught during unannounced inspections, and then find themselves not only paying fines, but also for repairing any damage they have caused. In short, it just makes common sense to inspect tanks on a regular basis.
Tanks serve in two ways to protect the sewer piping and decrease the amount of concentrated corrosive wastes that are discharged into the environment:
1. They can be used simply as dilution basins in which wastes are mixed with water to produce diluted solutions. In many laboratories, this will effectively reduce the possibility of contamination of municipal sewer systems.
2. In other applications, where higher concentrations of acids are being discharged, the tank should be charged with limestone chips with a high (90%+) calcium carbonate content. As wastes are discharged into the unit, chips will react with the acid to form less corrosive materials. In this type of operation, the tank needs to be checked periodically and recharged with new limestone. Chips should be no smaller than one inch or larger than three inches in diameter. Too large a chip will not give satisfactory chemical reactions with corrosive wastes, while too small a chip will lump and channel in the tank. Landscaping or decorative limestone is not acceptable and should not be used.
Limestone with a calcium carbonate content of less than 90%, which includes most landscape limestone, may not provide the proper chemical reaction to sufficiently neutralize the acid waste and also greatly add to the sludge in the tank.
Proper maintenance of neutralization tanks is essential for proper neutralization of wastes in systems. Tanks must be cleaned out periodically of all sludge, debris and other materials and must be checked for the proper amount of limestone. A regular maintenance program of one to three months should be observed, depending on use.
Recharging should be facilitated on an as-needed basis considering usage and concentration of the acid waste. In an average school laboratory, fresh limestone likely needs to be added only at the beginning of each term…again with usage and acid concentration being the determining factors in recharging tanks.
Tanks should be placed on flat surfaces of sufficient strength to support the weight of a full tank. The tank should be placed in position, filled with water and the neutralization medium added. The medium should be added to the tank in such a manner so as to not damage the tank, the tank top, inlet and outlet connections, dip pipe, or the vent. The water added for this procedure is to slow down the impact of the limestone chips, but it is not necessary for the neutralization process. This neutralization material should fill the tank from its bottom to with-in one inch below the bottom of the outlet.
One of the most challenging and unique requirements faced in laboratory use is the ability of the tank to handle a great variety of chemicals and pH ranges from acids to caustics. For most applications, tanks molded from polyolefin (polypropylene or polyethylene) have been the answer. Polyolefin tanks have enjoyed a successful track record in thousands of applications in schools and industrial installations worldwide.
In a typical laboratory installation, tanks are rotationally molded of one-piece virgin polyolefin. They have welded external flanges with fittings that are polyfused and/or welded to the tank. Covers are manufactured of the same material and are either bolted down or screwed to the tank. Tanks should be protected from impact especially at temperatures below 40 degrees F.
Finally, remembering these important fitting rules can help ensure a long-lasting, care-free tank installation.
1. Do not allow weight on tank fittings
2. Plastic screws-on bulkhead fittings are designed to be tightened by hand. Over tightening can cause the fittings to leak
3. Tanks must be fully supported. They should never be suspended from the plumbing.
4. As a matter of routine, tank systems should be flushed with water on a regular basis.
In closing, it should be noted that with proper installation and regular maintenance, under counter tanks will provide safety and protection for the laboratory and the environment for many years to come. Although intended to be out of sight, tanks should never be out of mind.
Len Weiss is national sales manager of Scientific Plastics Inc. He is also a board member of Scientific Equipment and Furniture Association, (SEFA), a trade group promoting excellence in the manufacture of laboratory equipment. Scientific Plastics Inc. is located in Kansas City, Kansas. The firm manufactures sinks, trays, tanks, and piping and other laboratory equipment used in acid waste handling.
Adam Equipment is offering educators a free lab apron for every two Adam balances purchased this fall directly from Adam or from any of its dealers. The protective apron features a light-hearted “Weigh Cool” graphic. The bib-style aprons are a generous size with a neck adjustment slider for perfect fit. They feature three divisional pouch pockets and are washable and durably constructed for years of wear. Visit their Web site for full terms of offer. Adam Equipment supplies schools with reliable balances, including the recently-patented TBB Triple Beam plus a range of student-friendly electronic balances.
Scientific Plastics has expanded its line of trays for laboratory use. Offered in 135 sizes, trays are manufactured in three depths. Non-standard sizes are also available on special order. Trays are one-piece and are rotationally molded from high-density polypropylene for maximum strength and acid resistance. Featuring coved corners for ease of cleaning, trays are dishwasher safe. They are available in natural, gray, and black and conform to ASTM 1412-92. Scientific Plastics’ lab trays are designed for virtually all laboratory environments.
Axis 3 from Sheldon Laboratory Systems
Sheldon Laboratory Systems’ Axis 3 lab station design allows space for standard desktop computers, flat-screen monitors or individual laptops. It is suitable for all science applications, including chemistry, biology, physics and general science. Special features of the Axis 3 station include a uniquely shaped adjustable work surface that allows up to four students working in pairs facing the instructor or individually seated around the station’s perimeter. This specially designed station allows lab and lecture functions to be performed in one location, and its contoured edges accommodate comfortable movement around the station while providing quick access to a clean-up sink and utility services.
Virtual Chemistry Lab by Model Science
Model ChemLab is a unique product incorporating both an interactive simulation and a lab notebook workspace with separate areas for theory, procedures and student observations. Commonly used lab equipment and procedures are used to simulate the steps involved in performing an experiment. Users step through the actual lab procedure while interacting with animated equipment in a way that is similar to the real lab experience. ChemLab features a long list of pre-designed lab experiments for chemistry at the high school and college level.
American Science Labs
American Science Labs' specialty is lab design. They can design completely new labs or renovate an existing lab, utilizing as many of the existing facilities as possible. Either way, they will create a state-of-the-art learning environment for the student and teacher at a budget-friendly price. American Science Labs' furniture features sturdy laminate or wood cabinetry along with an assortment of top-quality work surfaces.
Biofit Lab Chairs
BioFit Engineered Products offers heavy-duty DD Series chairs for functional, cost-effective seating in school laboratories. The seat and backrest are of Duragrain woodgrain molded styrene, a strong resilient plastic that looks like wood, resists heat and chemicals, and is easy to clean and maintain. Both the seat and backrest are adjustable, making the chairs adaptable to multiple users and a range of body sizes. Controls enable the chair user to adjust seat height plus backrest height and tilt. The chairs are available with a fixed or adjustable-height footring and a choice of bases, casters and glides, and metal finishes.