What is Silver?

Silver is a chemical element with the symbol Ag and the atomic number 47. The metal occurs naturally in its pure, free form (native silver), as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite. Most silver is produced as a by-product of copper, gold, lead, and zinc refining. Pure silver is nearly white, lustrous, soft, very ductile, malleable, it is an excellent conductor of heat and electricity. It is not a chemically active metal, but it is attacked by nitric acid (forming the nitrate) and by hot concentrated sulfuric acid. It has the highest electrical conductivity of all metals, but its greater cost has prevented it from being widely used for electrical purposes. Silver does not oxidise in air but reacts with the hydrogen sulfide present in the air, forming silver sulfide (tarnish). This is why silver objects need regular cleaning. Silver is stable in water. 

What is Silver used for?

Silver is used to make jewellery, silverware, electronic equipment, and dental fillings. It is also used to make photographs, in brazing alloys and solders, to disinfect drinking water and water in swimming pools, and as an antibacterial agent. Silver has also been used in lozenges and chewing gum to help people stop smoking.

Sources and Routes of Exposure

Sources of Exposure

• Breathing low levels in air.
• Swallowing it in food or drinking water.
• Carrying out activities such as jewellery making, soldering, and photography.
• Using anti-smoking lozenges or other medicines containing it.

Routes of Exposure

Silver's wide variety of uses allows exposure through various routes of entry into the body. Ingestion is the primary route of entry for silver compounds and colloidal silver proteins. Inhalation of dust or fumes containing silver occurs primarily in occupational settings. Skin contact occurs in occupational settings, from the application of burn creams and from contact with jewellery. Silver can also gain entry into the body through the use of acupuncture needles, catheters, dental amalgams, or accidental puncture wounds.

Health Effects

• Exposure to high levels of silver for a long period of time may result in a condition called arygria, a blue-grey discolouration of the skin and other body tissues. Argyria is a permanent effect, but it appears to be a cosmetic problem that may not be otherwise harmful to health. 
• Lower-level exposures to silver may also cause silver to be deposited in the skin and other parts of the body; however, this is not known to be harmful. 
• Eye contact: may cause severe corneal injury if liquid comes in contact with the eyes. 
• Skin contact: may cause skin irritation. Repeated and prolonged contact with skin may cause allergic dermatitis. 
• Inhalation hazards: exposure to high concentrations of vapours may cause dizziness, breathing difficulty, headaches, or respiratory irritation. Extremely high concentrations may cause drowsiness, staggering, confusion, unconsciousness, coma, or death.
• Liquid or vapour may be irritating to skin, eyes, throat, or lungs. Intentional misuse by deliberately concentrating and inhaling the contents of this product can be harmful or fatal.
• Ingestion hazards: moderately toxic. May cause stomach discomfort, nausea, vomiting, diarrhoea, and narcosis. 
• Aspiration of material into lungs if swallowed or if vomiting occurs can cause chemical pneumonitis, which can be fatal.
• Animal studies have shown that swallowing silver results in the deposit of silver in the skin. One study in mice found that the animals exposed to silver in drinking water were less active than unexposed animals.
• No studies are available on whether silver affects reproduction or causes developmental problems in people.
• No studies are available on whether silver may cause cancer in people. 
• The only available animal studies showed both positive and negative results when silver was implanted under the skin.
• The EPA has determined that silver is not classifiable as to human carcinogenicity.

Silver Safety

First Aid Measure

Eye Contact: Check for and remove any contact lenses. Do not use an eye ointment. Seek medical attention.

Skin Contact: No known effect on skin contact; rinse with water for a few minutes.

Inhalation: Allow the victim to rest in a well-ventilated area. Seek immediate medical attention.

Serious Inhalation: Evacuate the victim to a safe area as soon as possible. Loosen tight clothing such as a collar, tie, belt, or waistband. If breathing is difficult, administer oxygen. If the victim is not breathing, perform mouth-to-mouth resuscitation. Seek medical attention.

Ingestion: Do not induce vomiting. Examine the lips and mouth to ascertain whether the tissues are damaged, a possible indication that the toxic material was ingested; the absence of such signs, however, is not conclusive. Loosen tight clothing such as a collar, tie, belt, or waistband. If the victim is not breathing, perform mouth-to-mouth resuscitation. Seek immediate medical attention.

Exposure controls & Personal Protection

Engineering Controls

• Use process enclosures, local exhaust ventilation, or other engineering controls to keep airborne levels below recommended exposure limits. 
• If user operations generate dust, fumes, or mist, use ventilation to keep exposure to airborne contaminants below the exposure limit.

Personal Protective Equipment

The following personal protective equipment is recommended when handling silver:

• Splash goggles
• Lab coat.

Personal Protection in Case of a Large Spill:

• Splash goggles
• Full suit
• Boots
• Gloves

Suggested protective clothing might not be sufficient; consult a specialist BEFORE handling this product.

Regulations

United States

Australia

Safe Work Australia: Safe Work Australia has set a time-weighted average (TWA) concentration of 0.01 mg/m³ for silver over a 40-hour workweek.