Question 1

The chemical agent(s) that produces highly reactive hydroxyl-free radicals and also decomposes to O₂ gas is/ are

Accepted Answer

Hydrogen peroxide is the only chemical agent mentioned in the options that produces highly reactive hydroxyl-free radicals and decomposes to O2 gas. Cidex, cationic detergents, chlorhexidine, and iodophors do not have the same chemical properties as hydrogen peroxide.

Question 2

All of the following pertain to hypochlorites, except

Accepted Answer

Hypochlorites are not found in iodophors. Iodophors contain iodine, which is a different type of disinfectant.

Question 3

All of the following are correct about iodophors, except

Accepted Answer

Iodophors are designed to release iodine slowly, not quickly, which helps reduce irritation and staining while maintaining antimicrobial activity.

Question 4

The sterilizing gas used in a special chamber is

Accepted Answer

Ethylene oxide is a commonly used sterilizing gas in special chambers, also known as ethylene oxide sterilizers. It can penetrate most materials and can effectively sterilize delicate medical equipment that cannot withstand other forms of sterilization. It is also used for sterilizing heat-sensitive materials, like plastics and electronics.

Question 5

Which of the following chemicals is a disinfectant for soft contact lenses?

Accepted Answer

Hydrogen peroxide is commonly used as a disinfectant for soft contact lenses. It effectively kills bacteria, viruses, fungi, and other microorganisms that could cause eye infections. It is also less likely to cause irritation or allergic reactions than other disinfectants like alcohol or glutaraldehyde. However, it is important to follow the recommended contact lens disinfection protocol and to use only approved products, as improper use or exposure to undiluted hydrogen peroxide can cause serious injury to the eyes.

Question 6

The compound that is an organic base containing chlorine and two phenolic rings and is used increasingly for hand scrubbing, neonatal washes, wound degerming, and prepping surgical skin sites is

Accepted Answer

The compound described in the question is chlorhexidine, which is an organic base containing chlorine and two phenolic rings. Chlorhexidine is commonly used as an antimicrobial agent for hand scrubbing, neonatal washes, wound degerming, and prepping surgical skin sites. The other options listed, such as carbolic acid, triclosan, formalin, and quarternary ammonium compounds, are not specifically described as having two phenolic rings or containing chlorine.

Question 7

All of the following are correct about food irradiation, except

Accepted Answer

The World Health Organization does endorse the process of food irradiation, as it has been found to be a safe and effective method for reducing bacteria and pathogens in food. The other statements are correct: food is not made radioactive, it is approved for certain types of meat in the U.S., it can increase shelf life, and all irradiated food must be clearly labeled.

Question 8

All of the following are phenols or phenolics, except

Accepted Answer

Chloramines are not phenols or phenolics. They are a group of compounds formed by the reaction of chlorine with ammonia and other nitrogen-containing compounds. Lysol, hexachlorophene, triclosan, and cresols are all examples of phenols or phenolics.

Question 9

Which of the following does not contain a heavy metal?

Accepted Answer

Tincture of iodine does not contain a heavy metal; it primarily contains iodine, which is a halogen, not a heavy metal.

Question 10

The easiest microbial forms to kill or inhibit are

Accepted Answer

Vegetative bacteria and fungi are the easiest microbial forms to kill or inhibit because they have weak cell walls and are actively growing and dividing, making them vulnerable to a variety of antimicrobial agents such as antibiotics, disinfectants, and antifungals.

Note: Naked viruses do not have an envelope that can be targeted by some antiviral drugs, but they are still difficult to kill because they rely on the host cell's machinery to replicate. Endospores are highly resistant to environmental stress and require specialized methods such as autoclaving to kill. Protozoan cysts can also be resistant to disinfectants and antibiotics. Mycobacterium and Staphylococcus are known to be resistant to many antimicrobial agents.

Question 11

Which is mismatched?

Accepted Answer

Chlorhexidine is not an alcohol, it is a chemical antiseptic.

Question 12

All of the following are benefits of food irradiation, except

Accepted Answer

Food irradiation does not make the food less nutritious. In fact, it can preserve the nutrients in the food by preventing spoilage and reducing the need for chemical preservatives. Therefore, all other choices (A, B, C, and D) are benefits of food irradiation.

Question 13

Which of the following is not used as an antiseptic?

Accepted Answer

Aqueous glutaraldehyde is primarily used as a high-level disinfectant and sterilant in medical environments, not as an antiseptic. Antiseptics are used on living tissues to reduce the possibility of infection, whereas disinfectants and sterilants like glutaraldehyde are used on non-living surfaces.

Question 14

Which of the following is officially accepted as a sterilant and high-level disinfectant?

Accepted Answer

Glutaraldehyde is accepted as both a sterilant and high-level disinfectant by various regulatory bodies, including the Environmental Protection Agency in the United States. The other options listed are not typically used as sterilants or high-level disinfectants.

Question 15

All the following are correct about detergents, except

Accepted Answer

The answer of All the following are correct about detergents,...

Question 16

Iodophors include

Accepted Answer

Iodophors refer to a group of compounds that release iodine slowly when dissolved in water or alcohol. Povidone iodine is an iodophor commonly used as an antiseptic in healthcare settings due to its broad-spectrum antimicrobial activity, low toxicity, and lack of resistance development. Chloramines, tincture of iodine, alcohols, and chlorhexidine are not iodophors.

Question 17

Ethylene oxide is

Accepted Answer

Ethylene oxide is sporicidal, meaning it can kill bacterial endospores which are highly resistant to other types of disinfectants and sterilizing agents. It is used to sterilize medical and laboratory equipment, as well as certain types of food products. It is not effective with high heat or as an antiseptic against anaerobes, and it is not the active agent in household bleach. Additionally, ethylene oxide is not a halogen.

Question 18

Alcohols

Accepted Answer

All of these choices are correct. Alcohols can denature proteins, disinfect items by soaking, act as skin degerming agents, and dissolve cell membrane lipids at concentrations of 50% or higher.

Question 19

Which of the following is being used to replace hypochlorites in treating water because of the possibility of cancer-causing substances being produced?

Accepted Answer

Chloramines are used as an alternative to hypochlorites in water treatment because they produce fewer disinfection byproducts, which can be carcinogenic.

Question 20

Which control method would not be a suitable choice for killing Mycobacteria in a capped culture tube?

Accepted Answer

Ultraviolet (germicidal) light is not effective for killing Mycobacteria in a capped culture tube because UV light does not penetrate glass or other opaque materials, thus it cannot reach and kill the bacteria inside a capped tube.

Quiz 11: Physical and Chemical Agents for Microbial Control

The chemical agent(s) that produces highly reactive hydroxyl-free radicals and also decomposes to O2 gas is/ are