PPE guidelines for melting and pouring operations.

A guide has been developed to assist ferrous and nonferrous foundrymen in preventing minor-to-fatal injuries through the use of proper personal protection equipment (PPE).

Despite their improvements in worker conditions, high-efficiency furnaces have not eliminated the potential hazards and injuries associated with metal melting and pouring operations in foundries. Disasters still can happen and result in minor-to-serious burns and, possibly, a fatality. In these unfortunate instances, wearing the proper protective clothing can be the difference between walking away unharmed from a catastrophe or being seriously injured or killed.

MELT ACCIDENTS

Foundry melt-related accidents have been reported to occur for a number of reasons, including:

* the introduction of wet or damp metal into the melt, causing a water/metal explosion;

* lack of operator skill during temperature monitoring, sampling or the addition of alloying compounds, causing metal splashing;

* dropping large pieces of charge material into a molten bath, causing metal splashing;

* improper attention to charging, causing a bridging condition;

* failure to stand behind safety lines, causing a trapping situation;

* coming into contact with electrical conductors, overriding safety interlock switches or coming into contact with incompletely discharged capacitors, causing electric shock or electrocution.

Molten Metal Splash

The one hazard that must be examined and eliminated is the incapsulation or entrapment of any water, moisture or liquid-bearing material in molten metal. The water instantaneously turns to steam, expanding to 1632 times its original volume, and produces a violent explosion. This occurs without warning and throws molten metal and possibly high-temperature solids out of the furnace, placing workers, the furnace and nearby equipment at high risk.

A water/metal explosion can occur in any type of furnace but for induction furnaces, for example, the aftereffects can be more serious. Additional explosions may occur because of liquid in a ruptured cooling system coming in contact with molten metal in the bath.

Explosions also can occur without the presence of molten metal when sealed drums or containers containing water are charged into an empty but hot furnace. In this case, the force of the explosion ejects the newly charged material from the furnace, placing workers and equipment at risk, while also possibly damaging the furnace's refractory lining.

Other related hazards include cold charge or tools and easily fragmented materials that contain a thin layer of surface or absorbed material. On contact with the bath, the moisture turns to steam, causing spitting or splashing. In ferrous foundries, the greatest splashing risk occurs toward the end of the melt, when a worker adds ferroalloys or introduces tools such as slag rakes or sampling spoons into the melt. Ferroalloys can absorb moisture from their surroundings as a thin film of condensation. In a nonferrous foundry, spitting or splashing can accompany the introduction of ingots into the melt.

The violent and unpredictable nature of this water/metal explosion makes the wearing of safety clothing by melt shop workers imperative.

PPE GUIDE

AFS' Safety and Health Committee (10-Q) recently published guidelines for metalcasters to use when selecting personal protective equipment (PPE) for metal melting and pouring operations. The guidelines address nine categories, which include:

* clothing (ferrous metals);

* clothing (nonferrous metals);

* clothing (aluminum);

* eye protection (all metals);

* face protection (all metals);

* head protection (all metals);

* foot protection (all metals);

* hand protection (all metals);

* hearing protection (all metals).

This guide was developed for use by foundries when completing a hazard assessment of their melting and pouring operations and as a proactive guide to prevent the Occupational Safety and Health Administration (OSHA) from issuing a compliance directive for their compliance officers without input from the metalcasting industry.

A hazard assessment is a key element of a viable safety program and is required by OSHA standard 29 CFR 1910.132 (d). This standard requires employers to evaluate all workplace jobs to identify potential hazards. Once a hazard is identified, engineering controls should be used to abate it. If that cannot be done, PPE must be used.

Using the PPE Guide

Each section of the PPE guide is broken down into four columns:

* Potential hazards and considerations - Listed are dangers and special situations to expect when in the melting and pouring areas of a foundry;

* Comments - These are additional helpful comments to guide readers in the proper selection of PPE;

* Universal - PPE listed in this column are minimum mandatory requirements for each individual in melting and pouring operations;

* Application specific PPE suggestions listed in this column are to be considered after identifying the hazard(s) and its severity. Keep in mind that all operations may not require specific protection beyond universal requirements.

[TABULAR DATA FOR TABLE 1 OMITTED]

It is apparent from the chart that PPE requirements vary depending upon metal type, amount of metal poured and engineering controls used within a particular foundry. It is not always necessary or advisable to have all melters and pourers dressed in aluminum "space suits" all of the time. Only when the hazard is present is PPE required. Table 1 and the sidebar on p. 59 will help foundrymen choose the PPE that best suits their particular needs based on a carefully completed hazard assessment(s).

RELATED ARTICLE: PPE From Head To Toe

While complete protection is vital for melting and pouring operators, certain parts of the body require special attention. Discussed below are those specific areas of the body and the suggested equipment and methods of protecting them, as stated in AFS' "Recommended Clothing and Personal Protective Equipment (PPE) for Metal Melting and Pouring Operations."

* Head: To prevent injuries from falling objects, moving equipment and/or overhead obstructions, as well as burns from physical contact with molten metal splash, sparks, flames and/or hot surfaces, hard hats that meet American National Standards Institute (ANSI) Z89.1 standards (Protective Headwear for Industrial Workers) or cotton or wool caps are recommended;

* Face: To prevent facial injuries caused by molten metal splash and/or infrared and ultraviolet radiation from high-temperature surfaces or electric arc, use tinted acrylic or #40 wire mesh face shields and wear safety glasses with side shields along with face protection:

* Eye: To prevent injuries caused by foreign bodies, burns and/or infrared and ultraviolet radiation from high-temperature surfaces or electric arc, refer to the eye protection specification in ANSI Z87.1 (Practice for Occupational and Educational Eye and Face Protection), use minimum-protection safety glasses with side shields and darker glasses for intense radiant energy;

* Hearing: In regard to hearing loss due to noise exposure, refer to OSHA 1910.95 for Hearing Conservation requirements and be aware that foam ear plugs or urethane materials may be combustible;

* Hand: To prevent burns from physical contact with molten metal splash, sparks, flames and/or hot surfaces, as well as scrapes, cuts and abrasions from handling charge materials, consider the need for dexterity and grip security when operating equipment and use mitts, cover mitts, cover pads or gloves. If there is no chance of metal being spilled into the glove, consider the gauntlet-type glove. Recommended materials for the gloves include leather, cotton, wool, kevlar, wool-lined kevlar and other heat-resistant materials. Do not wear Nomex or phosphorous-treated (flame-retardant) cotton gloves as molten metal tends to stick to the fabric;

* Foot: To prevent injuries from falling or rolling objects, molten metal spill or burns from hot surfaces, use foot protection that meets ANSI Z41 (Personal Protection - Protective Footwear). For all melting and pouring operations, a leather safety shoe with a smooth toe, such as a 6- or 8-in. engineer's boot, is recommended. If metatarsals or lace boots are worn, select a built-in design or wear spats or leggings that cover areas where molten metal or sparks could lodge, such as in the tongue area. Wear pants or leggings that cover the top of the boot, never tucking the pant legs inside the boot or spat. Also, do not use shoes with zippers or materials such as nylon, which could melt or ignite.