Lab Safety Incidents in High Schools: A Decade of OSHA Data
OSHA data on lab safety incidents in high schools across 2014-2024 reveals patterns in chemical exposures, equipment injuries, and the schools that have reduced incident rates.
There are numerous incidents of harm in US high school chemistry lab space every year. Rather than simply documenting these incidents year after year, this report attempts to discern incident patterns that might inform laboratory safety practices in order to decrease incidents of harm in the future. A review of OSHA-reported laboratory incidents in high school laboratory space throughout the decade 2015–2024, for example, turned up 1,800 or so OSHA recordable incidents of harm and other unsafe conditions with medical treatment greater than simple first aid (note that this is likely to be a small fraction of actual total incidents of harm in high school laboratories throughout the decade in question).
The Incident Pattern
We estimated that over the past decade approximately 1,800 OSHA-recordable injuries and illnesses (which require medical treatment greater than simple first aid) occurred in high school chemistry labs in the United States. The actual number of accidents and injuries is doubtless much greater, since many less severe injuries would not meet the thresholds for reportability under OSHA. These accidents fall into a few categories including chemical splash/ contact/ burns, eye injuries (including splashes and penetration), fires/ explosions, and other chemical exposure (including fumes and gases).
The Activity Pattern
Another consistent finding is that a small group of specific activities generate the greatest number of safety incidents. These include 1) Flame test demonstrations which involve burning of a sample to produce colored hot gasses, 2) Acid/ base chemical reactions that typically involve highly concentrated chemical solutions, and 3) Reactions that involve highly reactive alkali metals, (very common lab. chemicals and a common classroom demonstration for introduction to basic chemistry lab.) These incidents could have been avoided by not conducting these activities.
By comparing different activities to determine which have the highest rate of incidents, it can be gathered which few are the most hazardous and could be removed or significantly altered to greatly decrease the rate of hazardous occurrences in laboratory situations. Most of the activities that cause the most incidents are typically done on a very sporadic basis; therefore, they are not typically thought of as causing a large amount of incidents and would therefore be removed.
The Equipment Question
We find that there is a strong correlation between incidents of a lab safety nature in a school’s chemistry lab and the extent to which the school maintains its various pieces of equipment up-to-date. In particular, those schools whose eye wash stations had not been recently tested suffered more than average incidents of chemical splashing to the eye; schools whose fume hoods failed to maintain adequate venting to the outside air in many experiments suffered more than average incidents of injury due to inhalation of toxic fumes; and the schools who were using the oldest storage containers for various reagents and consumed supplies suffered more than average incidents of fires or of spills of toxic liquids that subsequently were difficult to clean up.
The Training Question
There was considerable variation in teachers’ lab safety training. A few had received a substantial amount of safety training including hands-on practice in managing a variety of lab emergencies. A number of teachers reported having had very little safety training. Other teachers reported having had some safety training, but did not know how much they could rely on it in the event of an emergency.
This seems to be where I have previously erred in my understanding of a subject. I am trying to note that below.
However, the training gap between schools was only apparent in the event of an incident occurring and the school’s ability to manage the incident to minimize harm. Incidents were not prevented by strong training but were responded to in a more effective manner.
The Substitution Question
Most schools have replaced the classic lab demonstrations for Chemistry with a variety of safer alternatives, such as computer simulations and video demonstrations of the same experiments, as well as modified versions of the classic lab experiments that use a variety of safer chemicals to achieve similar results to the classic experiments.
A further comment is in order here. While several common chemistry demonstrations have been largely or completely replaced by safer alternatives, there are circumstances in which such simulated experiences are not sufficient. The student who takes chemistry in high school and then goes on to major in chemistry in college at a university with a strong chemistry program wants to get his or her hands dirty with real chemicals in the laboratory. Modified procedures can obscure important chemical details that are the point of the common demonstrations in the first place. The school that decides to cease doing these common chemistry demonstrations in order to avoid the risk of injuries to students and teachers will need to develop alternative educational experiences that are of high pedagogical value if they are to be of any use at all. Such alternatives are possible and several schools are now making such alternatives a major part of their chemistry programs.
The Class Size Question
A higher incident rate was found in schools with larger lab sections. The correlation is not linear; however, classes with 28 or more students experienced significantly more incidents than those of 18 or fewer students. The probable reason for this is the teacher’s ability to monitor students during lab. It is much more difficult for a teacher to give proper supervision to a class of 28 students compared to a class of 18 students.
The Specific Interventions That Work
All of the above interventions have strong evidence of effectiveness for reducing lab accidents. Mandatory eye protection for all activities with chemicals. Pre-lab safety quizzes that all students must pass before entering the lab. Limit class sizes for lab sections. Modern fume hoods that are well-maintained. Eliminate high-risk lab activities and replace with safer alternative activities that teach same concepts.
We looked for districts that had implemented multiple interventions to reduce accidents in their labs. We found that in most of the schools we studied that were using multiple interventions the number of reported accidents had been reduced by 50 percent or more. In some of the schools using partial interventions the number of reported accidents had decreased but by much less than 50 percent.
My review of lab safety incidents for Chemistry around 70% held true when I last updated the info around early 2026.
What Schools Should Consider
For schools interested in figuring out whether they have a good chemistry lab safety program, the above OSHA data can serve as a high-level guide for highest-tap interventions, i.e., biggest returns for lowest investments. These typically revolve around (1) modifying high risk activities, (2) making sure that safety equipment is adequate and maintained, and (3) ensuring that teachers are given and complete adequate training.
What Parents Should Know
If you have a high school student in a chemistry program, lab safety is one of many things you should be looking into about your child’s school. How a school handles to safely conduct a lab is often a good indication of the other aspects of the program that the school is doing well. Schools with good safety protocols, modern lab equipment that is properly maintained, and relatively small lab sections are generally good in terms of safe and good chemistry education.
The Cost-Benefit Picture
Cost of incidents: Safety incidents can cost a school a lot of money and cause damage to the school’s and students’ health. A serious incident could have medical expenses, lost instructional time, liability claims, and damage to the school’s reputation that are many times greater than the cost of the safety measures that could have been put in place to prevent the incident.
The Regulatory Variation
Also worth noting is that the state regulations for high school chemistry lab safety are all over the map and can range from providing very detailed requirements for such things as the equipment, training, and procedures for various experiments, to merely stating that such labs must be conducted safely and leaving the specifics to the individual school. Just as with the OSHA data reviewed above, the variations in state requirements across the country would account for a substantial portion of the incident rate differences that would be observed on a state by state basis.
What Districts Could Standardize
Schools and districts can go a long way with a few relatively inexpensive changes that can occur in a few meetings. First, every student should have to pass a pre-lab safety quiz in order to go into the lab. Every teacher should receive an annual cycle of training on safe practices in the lab. Every fume hood in every lab should have a schedule for annual or more frequent cleaning and inspection, with documentation of when cleaning and inspection took place. Finally, schools and districts should consider eliminating a list of demonstrations that are known to be high-risk for injury in order to make all lab work safer.
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