Screen Printing Safety And Compliance
Whenever we come in contact with an industrial chemical, we should have a well-informed awareness with acute sensitivity for the Safety And Compliance issues, such as the effects of chemicals on skin, eyes, ingestion and breathing. The screen printing industry is under lot of pressure by EPA, OSHA, State and Local regulators. Some regulations seem to be fair for the safety of workers, air, water and ground. Then the industry faces overly zealous inspectors who make the businesses aggravated. Readers are welcome to find out answers for environmental or health issues by calling Screening Supplies Store. The new SDS sheets required for each product usually give detailed health and environmental effect of every product. The owners and managers must pay attention so that they can have safe environment for them and their work force. We will briefly examine some of the safety issues in this paper.
What is unsafe about screen printing
We will start with the Hazmat chemicals. Any chemical that can harm people, animals, fish, environment, water, air or ground is considered as Hazmat. Those chemicals are regulated by different agencies, such as Environmental Protection Agency (EPA), Occupational Safety and Health Administration (OSHA), Nuclear Regulatory NRC, Department of Transportation; each agency has its own codes and law. OSHA takes issue with human health or the workers who are exposed to these hazardous chemicals. The chemicals could be carcinogen, dangerous for skin, lungs, eyes, mucous membrane and they could be Oxidizers, sensitizers, corrosive, flammable, unstable or reactive. The EPA has the same consideration as OSHA and adds those effects of chemicals on the air, land and water, animals, and marine life.
When it comes to human health, there are four possible ways that the any chemical would enter the body through:
Safety precautions one should take
First, let us look into simple general precautions one can take. In all four categories the attention of a physician in severe cases should be considered after routine procedures. For inhalation, person should go out in open fresh air- artificial respiration or oxygen if breathing stopped. Any contact with screen chemicals, wash with soap and water thoroughly. For eyes flush the eyes with water for fifteen minutes. In most cases of ingestion of chemical do not induce vomiting- consulting a doctor in severe cases is the right thing to do.
As we have become more concerned with rising rate of cancer cases, we have to be alert regarding what chemicals are carcinogens. National Toxicology Program (NTP) has published the report on Carcinogens RoC that tells us the chemicals that cause cancers or have potential to cause cancer. OSHA has also published the names of chemicals that may cause cancers. In this regard, it is important for the health of screen printers to look at the toxicological information about the product that they may be using or plan to use. You may find on your SDS sheet of each product LD50 and LC50 (used for marine life) those are the lethal dose and lethal concentration to kill the 50% population in a given time; it is given in mg/ kg body weight (On rats).
Air and Environmental Pollution Hazards
The air we breathe with a simple expectation that the air ought to be clean. In the screen printing rooms where we apply emulsion, clean screens and fuse Plastisol ink through heating by Flashing and drying and thereby introducing fumes in the air that carry some Vinyl Chloride into the air that may cause serious ill effects on health. There is nothing more important than installing an approved NIOSH ventilator. What goes in the air does not stop around us; the fumes go up to the stratosphere, affecting the Ozone layer. The thinning of Ozone layer may cause ill health effects on humans. The EPA through Clean Air Act provided the list of Ozone – Depleting Substances (ODS). Those are mostly solvents with the exemption of some solvents such as Acetone and Chlorinated solvents. One exemption was given to the solvents with very low vapor pressure less than >.01. Most of the screen chemical products are limited to carry not more than 100 grams/liter of VOC (Volatile Organic Compounds) that have higher vapor pressure at ordinary room temperature. Most Press washes or screen washes, screen openers, and Ink-degradent, do not meet the criteria. As a matter of fact most of these products used in screen printing industry have higher VOCs, going as high as at least 4300 grams per liter. These products affect the Ozone layer. California has lead in the Clean Air Act efforts. Through SCAQMD, Rule 1171 and proposal 65(Right to know law), California has become the leader state in the union to promote health and safety of human health, air and land. Under Rule 1170 the amount of VOCs have gone to as low as 28 grams/ liter for most cleaners.
Polluting our Water
The subject of pollution to our water system, rivers and sea is also very important. Most of the chemical products including Emulsion, Screen chemicals, Plastisol, solvent and water base inks, and Recalimers or strippers should not be allowed to go into sewer system. The aquatic life and echo system as we know it today would be severely affected if the blatant water pollution continues to go on uncontested. The fish in our water ways have to be protected. So it is a good idea to look at the Fish toxicity that goes LC50 number. At this point we should also consider the bio-degradability of chemicals. All organic compounds as food, human and animal bodies, and trees grow or live die and biodegrade itself in time. Every organic compound has a Half Life, meaning that in a specific period half of the product would disintegrate itself.
The last topic is the ground pollution. The non-hazardous waste can be picked by industrial waste removers. The problem is the hazardous waste. The federal government under title 40 has given detailed codes of the products that are highly regulated. The hazardous chemicals have five categories (1) Radio Active any substance that emit radiation (2) Ignitability – Any chemical that can ignite at high temperature (3) Reactivity- That can react with water or heat and may explode (4) Toxicity- ill health or damaging effects on skin, eyes, and can make people sick (5) Corrosivity- Any product that has less than PH 2 or higher than 12.5
So on the SDS sheet, look for any ingredient that has RCRA hazardous component regulated under 40CFR 261. The SARA titles give you the chemicals that are highly toxic. For hazardous materials there is a Reportable quantity (RQ) – Each chemical in that category should be carefully looked into.
The Extreme Danger of FIRE!
Let us look at the flammability of certain chemical products. Flash Point less than 100F is considered flammable and between 100 to 200F as combustible. For DOT purpose, the shipping of any chemical product under 140F is considered as flammable. UPS and FedEx has developed their list of products that can’t be shipped as regular products, such as corrosive, flammable, oxidizers and chlorinated products. Department of Transpiration (DOT) has regulations to ship hazardous chemicals. For the screen printing industry all those four categories talked before have to be followed under their laws.
Then there are ratings that is shown on the package as Packaging code number 1, 2 or 3, three the most flammable, such as Acetone or Heptanes. So when you receive a package through Fed ex or UPS, anything less 140 F should be sent to you with the Hazmat label. But then the rating and the limited packaging applies. If you see a blue and white label with the letters ORMd, that means that the chemicals is Hazmat but allowed to be sent within a limited quantity. That is one of the reasons that Xenon Product used only non flammable products, especially in the manufacturing of Activator for Cyanoacrylate. If you have to use a flammable product, provide good ventilation and do not allow any spark in the area, such as cigarette smoking. There is a lot more details when it comes to the safety, health, environment, regulations and good operating procedure.