Indoor Air Quality Considerations for Injection-Molding Plastics Workers

Today, mass-production injection-molding allows millions of the same plastic products, everything from toys to sporting goods and toothbrushes to furniture, to be made and utilized world-wide.

In 1872, John W. and Isaiah Hyatt patented the first injection-molding machine which used a plunger to inject plastic into a mold via a heated cylinder. Twenty years later, America’s involvement in World War II created a need for large quantities of cheap, automated goods to be produced quickly, often thousands of times for the same part or unit. The Hyatt brothers’ invention was improved upon to meet those needs. Today, mass-production injection-molding allows millions of the same plastic products, everything from toys to sporting goods and toothbrushes to furniture, to be made and utilized worldwide.

Due to the magnitude of items being manufactured, a workforce relative to the size of the production yield is necessary. Employing over 1.1 million workers in the United States, the plastics industry represents a substantial portion of American workers. (1) And while the plastics industry is conscientious about keeping their workers protected, there are still safety and health concerns – some of which stem from compromised indoor air quality (IAQ).

The Canadian Centre for Occupational Health and Safety describes injection-molding manufacturing as a process where,

… injection molding machines produce molded plastic parts by melting plastic pellets, injecting the molten material into a mold, and cooling the plastic material. This process involves many machine parts and tasks such as opening the operator’s gate, servicing and maintaining the machinery (lockout/tagout), and manually feeding the plastics materials. Any one of these processes can cause a worker harm if the proper precautions are not taken. (2)

Workers with the highest occupational risk of suffering from illness from poor IAQ tend to be those who work directly with raw materials when the plastic is being heated, mixed, and cooled. (3) According to the US Bureau of Labor Statistics, there are over 340,000 production workers in the plastics industry (4) many of whom may be vulnerable when exposed to vapors and mists that are emitted during the injection-molding process. These fugitive emissions result from heat degradation of the plastic polymers. If not captured, these fumes can cause significant health problems in the form of respiratory illness.

Ailments vary in degree from asthma to Legionnaires’ disease, a potentially life-threatening form of pneumonia (5) caused by the Legionella bacteria – an organism found in the water and mists used to cool the molds and machinery. Elevated concentrations of Legionella are released into a worker’s breathing space and, once inhaled, can pool in the lungs, obstruct breathing, and in some cases, cause death. OSHA believes that the nearly 6,000 reported cases of Legionnaires’ disease is an inaccurate count and estimates that number to be between 8,000-18,000 people who are hospitalized annually from exposure to the bacteria. (6)

But injection-molding plastics workers have a low risk of contracting illness when proper safety measures are in place. Employees should routinely wear protective equipment (such as facemasks) and clean indoor air quality should be maintained with vigilance. The most successful means of guaranteeing an unpolluted indoor environment is by controlling fumes via source capture and fume extraction. Our Extract-All™ line fume extraction systems eliminate vapors at the source. While we carry a full line of ambient and central systems, our most popular model is the SP-800 mobile fume extractor.

To ensure your workplace has an IAQ that is healthy for all employees, contact an AIRSInc specialist to evaluate and offer control measures for your clean air vulnerabilities.