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Gas Mask - Garrett Morgan


Air-purifying: filtering the air.

Ammonia (NH3): often used in cleaning products and fertilizers.

Apparatus: A device or equipment used for a specific purpose.

Ash: The powdery residue left after the burning.

Carbon monoxide (CO):  A poisonous gas produced by incomplete combustion of carbon-based fuels.

Clapper valves: Valves that allow air to flow in one direction but prevent it from flowing back in the opposite direction.

Combustion: The process of burning.

Contaminating substances: Substances that cause pollution.

Defender: A person or group defending against an attack.

Dissipate: Spread out and become less concentrated.

Hydrogen cyanide (HCN): A toxic gas.

Inhaling: Breathing in.

Mining Engineer: A person who specializes in the engineering aspects of mining, such as designing and operating mines.

Nitrogen Oxides: Gases containing nitrogen and oxygen, such as nitric oxide (NO) and nitrogen dioxide (NO2).

Oxidized: Combined chemically with oxygen.

Particulates: Tiny particles or substances suspended in the air.

Patent: A legal document that grants exclusive rights to an inventor for their invention.

Prevailing wind: The dominant wind direction in a specific area.

Pulmonary irritation: Irritation of the lungs.

Respirator: A device designed to protect the wearer from inhaling harmful substances, by filtering the air.

Self-contained: Complete and independent.

Simultaneous: Happening at the same time.

Thermal: Caused by heat.

Toxic: Harmful or poisonous.

Trenches: Long, narrow ditches used for military purposes, such as defense during warfare.

Garrett Morgan 


There is no single inventor of the “gas mask”.

Leonardo Da Vinci, is said to have originated the respirator concept when he suggested that a finely woven cloth be dipped in water to protect sailors from a toxic powder weapon he had created.

An early gas mask to be used by miners was introduced by Alexander von Humboldt in 1799, when he worked as a mining engineer in Prussia

Lewis P. Haslett got the first United States patent in 1849 for the air-purifying respirator. Called “Haslett’s Lung Protector,” the wearer had access to filtered air due to the two one-way clapper valves. One valve allowed inhalation of air through a filter made of moistened wool or other porous material and the other released exhaled air into the atmosphere.

In 1850, Benjamin Lane of Cambridge, Massachusetts received the first U.S. patent for a self-contained breathing apparatus called “Lanes Pneumatic Life Preserver.”  His respirator, rather than filtering the air entering it, carried a supply of compressed fresh air.

In 1877, George Neally designed a “smoke-excluding mask”. 

In 1912, Garret Morgan submitted his Safety Hood and Smoke Protector for patent and received the patent on October 23, 1914. His safety hood device was simple and effective, whereas the other devices in use at the time were generally difficult to put on, excessively complex, unreliable, or ineffective.

This device had a cotton hood with two hoses which hung down the floor, allowing the wearer to breathe the air found there. His device used a wet sponge to filter out smoke and cool the air.

Smoke is a collection of airborne solid and liquid particulates and gases emitted when a material undergoes combustion together with the quantity of air that is mixed into the mass. It is commonly an unwanted by-product of fires.

Smoke rises because hot air is less dense than cool air. When you add heat to a substance, the molecules in that substance react to the heat by vibrating more causing the substance to expand (MAJOR EXCEPTION; when ice is heated and turns to water it contracts) and it becomes less dense the Because fire produces a lot of hot air, it makes quite a big wind current as it rises, and that drags the smoke particles upward with the air.  

The visible particulate matter in such smokes is most commonly composed of carbon (soot). Other particulates may be composed of drops of condensed tar (various compounds), or solid particles of ash.

The chemical composition of smoke depends on the nature of the burning fuel and the conditions of combustion.

Fires with high availability of oxygen burn at a high temperature and with small amount of smoke produced; the particles are mostly composed of ash. High temperature also leads to production of nitrogen oxides (NOx). Carbon and hydrogen are almost completely oxidized to carbon dioxide (CO2) and water (H2O).

Fires burning with lack of oxygen produce a significantly more compounds, many of them toxic. Partial oxidation of carbon produces carbon monoxide (CO), nitrogen-containing materials can yield hydrogen cyanide (HCN), ammonia (NH3), and nitrogen oxides (NOx) among other substances.

In most house fires, there are other contaminating substances that lead to an extensive range of toxic chemicals formed as a result of fire.  Smoke inhalation is the primary cause of death in victims of indoor fires. The smoke kills by a combination of thermal damage (heat), poisoning (inhaling of other compounds other than air) and pulmonary irritation caused by carbon monoxide (CO), hydrogen cyanide (HCN) and other combustion products.


As is the case with many inventions, there is simultaneous parallel development in more than one location.

“…And what about the gas mask? Nope, [Garret Morgan]… didn't invent that either. What he invented was a safety hood you put over your head, while a tube dangled down to the floor to avoid inhaling smoke at standing height. It was meant to be useful to fire fighters. Now compare Garrett's1916 safety hood to a gas mask the British were issuing to their soldiers in the trenches of WWI in 1916, and the absurdity of this lie becomes even clearer -


On July 28, 1914 World War 1 started. The first use of poison gas on the western front (where German troops faced British and French troops) was on April 22, 1915, by the Germans. Soon afterwards the British added a long cloth which was used to tie chemical-soaked mouth pads into place, and which was called the Black Veil Respirator. The pads provided no protection when dry, so the Black Veil could work for about five minutes against a normal concentration of chlorine.

The development of protection against poison gas on the battle front took a different direction than those who were trying to develop protection against smoke from fires. The reason being that smoke rises and the purpose of using poison gas on the battle field is to kill people who, are close to the ground. This required the use of gases that are heavier than air.

This first poison gas used was chlorine. Chlorine as part of salt is found in the ocean, it is a regular part of our diet, and is used as a bleaching agent (Clorox bleach is based in Oakland, CA). In its molecular form there are two chlorine atoms joined together and in this form it is 2.5 times heavier than air (78% Nitrogen, 21% Oxygen and 1% Argon), and therefore stays closer to the ground than air.

In June 1915, Canadian Dr. Cluny MacPherson brought the idea of a mask made of chemical absorbing fabric and which fitted over the entire head to England, and this was developed into the Hypo helmet. It was simply a khaki-colored flannel bag soaked in hypo solution (glycerin and sodium thiosulphate); it protected against chlorine. The soldier placed it over his head and tucked the bottom into his tunic. No inlet or exhaust valve was provided, and the wearer's lungs forced the air through the material making up the bag. A fragile rectangular mica or celluloid window provided visibility.

Soon after introducing poison gas on the battlefield the Germans realized that their troops needed better protection against its effects. A key problem with the use of gas is that it relies on the prevailing wind to spread its effects. When the wind reverses before the gas has dissipated and blows back toward its launch point, it creates the same type of problem for the attacker as it does for the defender.

A benefit of war is that its dire circumstances often lead to rapid development of technological innovations. In 1915 the Germans introduced;





















By 1916, the British had developed their own gas mask. 

In 1916, the city of Cleveland was drilling a new tunnel under Lake Erie for a fresh water supply. Workers hit a pocket of natural gas (primarily methane (CH4) which is lighter than air). This resulted in a huge explosion and trapped workers underground amidst suffocating noxious fumes and dust.

The first two attempts to rescue the trapped workers failed. The attempted rescuers had become victims themselves by entering the tunnel and not returning.

Garret Morgan was roused in the middle of the night after one of the members of the rescue team who had seen a demonstration of his device sent a messenger to convince him to come and to bring as many of his hoods as he could. He arrived on the scene still wearing his pajamas, and brought his brother Frank and four of the hoods with him. Most of the rescuers on the scene were initially skeptical of his device, so he and his brother personally went into the tunnel along with two other volunteers, and succeeded in pulling out two men from the previous rescue attempts. He emerged carrying a victim on his back, and his brother followed just behind with another. Others joined in after his team succeeded, and rescued several more. His device was also used to retrieve the bodies of the victims that did not survive. Morgan personally made four trips into the tunnel during the rescue, and his health was affected for years afterward from the fumes he encountered there.

Cleveland's newspapers and city officials initially ignored Morgan's act of heroism as the first to rush into the tunnel for the rescue and his key role as the provider of the equipment that made the rescue possible, and it took years for the city to recognize his contributions. City officials requested the Carnegie Hero Fund Commission to issue medals to several of the men involved in the rescue, but excluded Morgan from their request. Later, in 1917, a group of Cleveland’s citizens of tried to correct for the omission by presenting him with a diamond-studded gold medal.


Morgan continued his work on the safety hood and later developed models that incorporated an air bag, which could hold up to 15 minutes of air making it a gas mask. By 1917, it was standard equipment in the United States Army.


Morgan worked hard to market the device, especially to fire departments, often personally demonstrating its reliability in fires. There was some resistance to Morgan's devices among buyers, particularly in the South, where racial tension remained high. In an effort to counteract the resistance to his products, Morgan hired a white actor to pose as "the inventor" during presentations of his breathing device; Morgan would pose as the inventor's sidekick, disguised as a Native American man named "Big Chief Mason," and, wearing his hood, enter areas otherwise unsafe for breathing. The tactic was successful; sales of the device were brisk, he would enter the tent full of black smoke, and would remain there for 20 minutes before emerging unharmed.

STEM Topic 16: Problem Set - 1
  1. If a gas mask filter can last for 8 hours of continuous use, how many filters will be needed for a team of 5 firefighters who are expected to work for 24 hours in a hazardous environment?

  2. A military unit has 180 gas masks and needs to distribute them equally among 6 platoons. How many gas masks will each platoon receive? 

  3. A manufacturer produces gas masks in batches of 50 units. If the production line produces 5 batches in a day, how many gas masks are produced in a day?

  4. In a gas mask drill, a group of 50 soldiers can complete the exercise in 10 minutes. How long will it take for a group of 200 soldiers to complete the same drill?

  5. A gas mask canister can hold 500ml of air. If a person inhales 100ml of air with each breath, how many breaths can they take before the canister is empty?  Note: ml = milliliters = 0.001 of a liter.

  6. A gas mask weighs 1.2 kg. If a soldier carries 3 gas masks in their backpack, how much extra weight are they carrying?

  7. A factory produces gas masks at a rate of 100 units per hour. If the factory operates for 8 hours a day, how many gas masks are produced in a day?

  8. In a gas mask testing facility, a sample of 50 masks is selected for quality control checks. If 5 of the masks are found to be defective, what percentage of the masks are defective?

  9. A gas mask filter needs to be changed every 6 months. If a military unit has 500 gas masks, how many filters will they need to replace in a year?  

  10. A gas mask has a circular eyepiece with a diameter of 8 centimeters. What is the area of the eyepiece?

  11. A gas mask has a rectangular filter cartridge with dimensions of 10 centimeters by 6 centimeters. What is the area of the filter cartridge?

  12. A gas mask has a triangular exhalation valve with a base length of 12 centimeters and a height of 5 centimeters. What is the area of the valve?

  13. A gas mask has a cylindrical canister with a radius of 3 centimeters and a height of 8 centimeters. What is the volume of the canister?    V = πr2h

  14. A gas mask has a spherical lens with a radius of 6 centimeters. What is the surface area of the lens?        A = 4πr2

  15. A gas mask has an oval-shaped intake vent with a major radius of 10 centimeters and a minor radius of 6 centimeters. What is the area of the intake vent? NOTE: The area of an ellipse = πab, where a is the major radius and b is the minor radius.

STEM Topic 16: Problem Set - 2
  1. The filtration system of a gas mask can remove 95% of airborne particles. If the mask filters out 50 particles, how many particles were present initially? Round your answer to the near whole particle.

  2.  A gas mask is designed to provide protection against toxic gases. If the mask can filter 80% of a toxic gas, and the initial concentration of the gas is 100 ppm (parts per million), what will be the concentration of the gas after filtration?   

  3. A manufacturer claims that their gas mask filtration system has an efficiency of 99.5%. If the mask filters out 475 particles, how many particles were present initially? Round your answer to the nearest whole particle.

  4. The concentration of a harmful gas in the air is measured at 500 ppm. A gas mask with a filtration efficiency of 90% is worn to reduce exposure. What will be the concentration of the gas after wearing the mask?

  5. A gas mask has a cylindrical filter with a radius of 4 centimeters and a height of 10 centimeters. What is the total surface area of the filter?        NOTE: Lateral Surface Area = 2πrh  Base Area + Top Area = 2πr²

  6.  The straps of a gas mask are attached to a rectangular face piece. If the length of the face piece is 15 centimeters and the width is 8 centimeters, what is the perimeter of the face piece?

  7. A gas mask storage box is shaped like a rectangular prism with dimensions 20 centimeters, 12 centimeters, and 15 centimeters. What is the volume of the storage box?

  8. A gas mask lens is shaped like a right circular cone with a radius of 5 centimeters and a slant height of 12 centimeters. What is the total surface area of the lens?
    NOTE: A = πr(r + l), wherel is the slant height.

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