Safety Talks

water utility operators and laboratory staff are often exposed to chemicals that can cause severe harm or even death. Many chemicals are extremely toxic, and even small quantities of them can be lethal. The effects of chemical exposure can be local–at the point of contact-or systemic. Systemic exposure occurs when the chemical agent is absorbed into the bloodstream and distributed throughout the body, affecting one or more organs. If you are exposed to a toxic chemical, the severity of damage will depend on the toxicity of the substance, its solubility in tissue fluids, its concentration, and the duration of exposure.

A person can be exposed to dangerous chemicals in the following ways:

• Dermal contact 
• Inhalation 
•  Ingestion 
• Ocular exposure 
• Injection

Dermal Contact

Spills and splashes in the laboratory or when loading chemicals into vats or mixing bays can result in contamination of exposed skin. When chemicals come in contact with the skin or mucous membranes, they can cause surface irritation at best. At worst, the chemicals can be absorbed into the bloodstream, causing systemic poisoning. Chemicals primarily penetrate the skin through hair follicles, sebaceous glands, sweat glands, and cuts or abrasions. Touching contaminated hands to the mouth, nose, and eyes can also cause chemicals to be absorbed into the body.

Inhalation

Inhalation is the most common road of entry for toxic substances. Toxic vapors, mists, gases, and even dust and particulates can be absorbed through the mucous membranes of the mouth and nose and subsequently travel into the throat and lungs and cause serious damage to those tissues. The effects are further compounded if the substances pass through the lungs into the circulatory system,

Ingestion

Mouth pipeting in the laboratory can lead to the ingestion of chemicals, but an even more common cause of unintentional ingestion of toxic substances is from foods that were stored in containers, such as beverage jars, that had been used to store nonfood items (paint, plant food, or other substances). Another unsafe but common practice that can lead to ingestion is storing food in a place where chemicals are stored or storing chemicals in a refrigerator used for food. 

Ocular Exposure

Unprotected eyes can become contaminated by splashing, aerosol contamination, or rubbing with contaminated hands. Many chemicals are capable of causing burns and loss of vision. Absorption into the bloodstream from ocular exposure can also occur quickly, because eyes contain many blood vessels.

Injection

Inattentive laboratory workers can have accidents with needles; an accidental stick can inject chemicals into someone inadvertently, Broken glass containers that contained toxic chemicals can also cut through skin, exposing a worker’s blood to unwanted contamination.

Avoiding Chemical Exposure

• Use PPE as required. 
• Never eat, drink, or smoke while using hazardous chemicals. 
• Always read the chemical’s SDS prior to use. 
• Make sure all chemical containers are properly labeled. 
• Always wash up after using chemicals. 
• Never smell or taste a chemical to identify it.
• know and practice all emergency evacuation and containment procedures and   Equipment
• Store all hazardous chemicals properly. 
• Always use hazardous chemicals as intended. 
• Avoid creating aerosols in the laboratory: do not use open vessels for processing  chemicals.

For more information, go to the US Chemical Safety and Hazard Investigation Board’s website: http://www.csb.gov.