Journey to Fulfilling the Most Important Functional Requirement: Safety First 🥼
- katielg980
- Jan 26, 2024
- 2 min read
My Augmented Reality for Composite Materials Manufacturing project prioritized safety for team members and beta testers. The end product is used in the composite materials manufacturing laboratory, so proper lab and AR safety needs to be followed. Below is my approach to maintaining a high standard of safety.
Researching & understanding lab safety
LSU conveniently provides a laboratory safety guide for all campus labs. Here is the list with the most critical rules highlighted.
LSU lab safety
Wear safety glasses or goggles at all times when in the lab
Wear proper clothing (solid toed-shoes, long pants, etc.)
Wear a lab coat as required
Use a glove-compatibility chart to determine the proper gloves to protect yourself
Wash your hands regularly, especially when taking gloves off
Do not wear gloves outside the lab
Do not eat in the working area of the lab or store food where chemicals are kept
Dispose of outdated and unused chemicals through EHS in a timely manner
Know the location of the emergency equipment in the lab (emergency eyewash/shower, fire extinguisher, spill kit, first aid kit)
Know and follow emergency procedures for lab and building
Store flammables in a rated flammable storage refrigerator or freezer only
Use toxic chemicals in the fume hood not on an open bench top
Do not modify equipment
Do not use extension cords
Working with composite materials like carbon fiber requires a few extra safety guidelines. Below are a few resources I used to determine proper safety procedures for working with these materials.
Composite material safety (community college lab assignment as the resource, webpage no longer available)
Possible routes of exposure:
Absorption – use gloves, glasses, appropriate clothing
Inhalation – use dust masks to protect against dust
Ingestion – never eat in work area while performing processes, and wash hands before eating
Injection – fiber particles and splinters, cover any open wounds
Work environment:
Know where safety equipment is
Good housekeeping - keeping areas clean as you go
Wipe up spills
Keep tools clean
Keep fabric remnants swept up
Properly dispose of mixing containers
Allergic reactions can be caused by any of the following:
Resins
Fibers
Hardeners and curing agents
Solvents
PPE:
Eye protection (safety glasses/goggles/face shields)
Skin protection
Lab coat
Gloves, differ depending on which chemicals you use
long pants
Closed toe shoes
Long hair should be tied back
Composite material safety (msdswriter: What's an SDS?)
"is used by chemical manufacturers and importers to convey both the physical hazards (pH, flashpoint, flammability, etc.) and also the health hazards (carcinogenicity, teratogenicity, etc.) of their chemicals to the end user."
SDS (safety data sheets) terminology:
Acute Exposure -An intense exposure over a relatively short period of time (carbon monoxide poisoning, cyanide inhalation, etc.)
Asphyxiate - A chemical (gas or vapor) that can cause death or unconsciousness by suffocation.
Carcinogen - A substance or physical agent that may cause cancer in humans or animals.
Chronic Exposure - A prolonged exposure occurring over days, weeks or years. A prolonged chemical exposure that does not cause immediate, obvious harm, or make you feel sick right away. You may not feel, smell or see the danger (e.g. mesothelioma from asbestos exposure, lung cancer from smoking, etc.)
Combustible Liquid -Liquids having a flash point at or above 100 degrees. Not as ignitable as Flammables.
Corrosive - A substance that causes visible destruction or permanent changes in human skin tissue at the site of contact, e.g. acids and bases.
Flammable Liquid - A liquid having a flash point below 100 degrees; more ignitable than combustible liquids.
Flash Point -The lowest temperature at which a liquid gives off enough vapor to form an ignitable mixture and will burn when a source of ignition is present.
Hepatotoxic, Nephrotoxic, Neurotoxic - Substances which are toxic to the liver, kidneys and nervous system, respectively.
Incompatible - The term applied to two substances to indicate that one material cannot be mixed with the other without the possibility of a dangerous such as fire, explosion or release of toxic vapors.
Irritant - A substance that produces irritating effect when it contacts skin, eyes, nose, or respiratory system.
Lethal Concentration (LC50) - The concentration of air contaminant that will kill 50% of the test animals in a group during a single exposure (inhalation exposure). Generally expressed in units of parts per million or mg of contaminant m3 of air.
Lethal Dose (LD50) - The dose of a substance that will kill 50% of the test animals in a group over a specified period of time following exposure. Generally, in units of mg of material per kg of subject body weight.
Mutagen - Anything which can cause a mutation in genetic material of a living cell. All mutagens are not carcinogens.
Oxidizer - A substance that readily gives up oxygen to stimulate combustion of an organic material.
Permissible Exposure - A human exposure limit that is published and enforced by OSHA as a legal standard. PEL may be either time-weighted-average (TWA). Limit: Exposure limit (8 hours), a 15 minutes short term exposure limit STEL, or ceiling © limit. Expressed in ppm or mg/m3.
Sensitizer - A substance which may cause no reaction in a person during initial exposures, but upon a later exposure will cause an allergic response to the substance.
Teratogen - A substance that may cause physical defects in the developing embryo or fetus when a pregnant female is exposed to that substance.
Threshold Limit Value - Similar to PEL above but are not legal standards for human exposure. Determined and published by the American Conference of Government Industrial Hygienists (ACGIH).
Another safety tip provided by the sponsor was to avoid the use of electronic devices with large, open access to the internal hardware while in the lab. Carbon fiber is electrically conductive. When working with pre-resin fiber, small shreds can fly into the air and a laptop's charging port, for example. This can cause permanent damage to the device, electric shock, or fire. Not good.
Researching & understanding AR safety
The team's faculty advisor had prior experience working with AR/VR technology. He provided me with VR safety card. Though the project is AR-based, many of the same principles apply. AR technology has fewer safety risks because a user sees holograms superimposed onto reality through clear lenses. As opposed to VR, where a user's view of their surroundings is entirely obstructed.
VR safety card
The following people should not use VR (AR) technology:
People with heart conditions
People with anxiety or PTSD
People with medical devices such as pacemakers
People with history of epilepsy or seizure
People feeling sick, fatigued, or unwell in general
Pregnant people
Movement awareness:
Be aware of your surroundings
Remain in contact with a facilitator in case of discomfort occurs
Discontinue use of the headset causes discomfort
Limit use to minutes at a time
Close your eyes, breathe deeply, and take a short break
Sit
Drink water
Common known discomforts:
Eye strain, blurred vision
Dizziness, disorientation, nausea, lightheadedness
Impaired balance or hand-eye coordination
Drowsiness, fatigue
Motion sickness
Real life safety applies in AR!
We were aware of the potential hazards associated with users with a history of epilepsy or seizures. The use of visual elements that are common triggers was avoided.
Epilepsy and seizure information
"Epilepsy is a central nervous system (neurological) disorder in which brain activity becomes abnormal, causing seizures or periods of unusual behavior, sensations and sometimes loss of awareness. Anyone can develop epilepsy. Epilepsy affects both males and females of all races, ethnic backgrounds and ages." Mayo Clinic article
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Photosensitive epilepsy is "triggered by flashing lights or contrasting light and dark patterns." Flashing lights between 3-30 hertz can trigger seizures. Also:
"Some people are sensitive to geometric patterns with contrasts of light and dark such as stripes or bars. Patterns are more likely to be a trigger if they are changing direction or flashing, rather than if they are still or moving slowly in one direction.
Flashing, flickering or patterned effects can make people with or without epilepsy feel disorientated, uncomfortable or unwell."
In the case that someone with photosensitive epilepsy is exposed to a trigger:
"Covering one eye completely with your hand will greatly reduce the photosensitive effect."
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Mozilla Developer article: Web accessibility for seizures and physical reactions
Possible triggers include:
Television screens or computer monitors due to the flicker or rolling images.
Certain video games or TV broadcasts containing rapid flashes or alternating patterns of different colors.
Intense strobe lights like visual fire alarms.
Natural light, such as sunlight, especially when shimmering off water, flickering through trees or through the slats of Venetian blinds.
Certain visual patterns, especially stripes of contrasting colors.
Possible reactions include:
Seizures
Vestibuler Disordera
Migraines
Nausea
Vomiting
"A flash is a potential hazard if it has luminance >or=20 cd/m2, occurs at a frequency of >or=3 Hz, and occupies a solid visual angle of >or=0.006 steradians (approximately 10% of the central visual field or 25% of screen area at typical viewing distances)."
Implementing safety guidelines
Personal protective equipment checkpoint:
The team decided to implement a checkpoint to ensure that users are wearing proper PPE before manufacturing a composite material. Here is a video of how the checkpoint looks for a user!
Handy virtual safety sheets:
I developed material safety sheets for both epoxy resin as well as carbon fiber.
PAR-Q form:
The IRB office required the team to produce a physical activity readiness questionnaire (PAR-Q) for beta testers to fill out before participating in the team's beta testing. This form was adapted from the IRB office's website to fit our project.
Because of the nature of this project, users will be moving around the lab space. We need to be sure that beta testers can perform the simple tasks required to manufacture a composite material and operate the HoloLens at the same time.
Motion sickness susceptibility questionnaire:
Each beta tester filled out the following motion sickness susceptibility questionnaire before participating in phase 1 of beta testing.
Because of the nature of the project, motion sickness is a concern for beta testers. Any beta tester with a high susceptibility to motion sickness was not allowed to participate in the study due to the risk of being dizzy or getting sick in a manufacturing lab around dangerous, expensive equipment. While motion sickness is a safety hazard, it is not a large concern because Microsoft's development team has integrated safety warnings and use recommendations that beta testers were made aware of. Overall, this project is safe, but to err on the side of caution, the IRB office wanted us to exclude potential participants who are extra susceptible to motion sickness.
