This fact sheet answers the most frequently asked health questions (FAQs) about perchlorates. For more information, call the ATSDR Information Center at 1-800-232-4636. This fact sheet is one in a series of summaries about hazardous substances and their health effects.erchlorates are colorless salts that have no odor. There are five perchlorate salts that are manufactured in large amounts: magnesium perchlorate, potassium perchlorate, ammonium perchlorate, sodium perchlorate, and lithium perchlorate. Perchlorate salts are solids that dissolve easily in water.
Instructions. 1  1. First of all, start with few and easy sign languages. Introducing too many signs at one time will be a useless effort. 2  2. Introduce the signs to your children in such a way as âyou say the word.â It helps in associating the word with the sign language.
The Invention of Sign Language. No one person invented sign language. It is reasonable to think that sign language was widely used before standardized systems were developed. Deaf people needed a way to communicate with others and many had a set of signs that they used at home to make themselves understood.The first system of hand signals as a language was invented by Juan Pablo de Bonet in 1620. He created the first book with sign language signals for teaching deaf people.he first system of hand signals as a language was invented by Juan Pablo de Bonet in 1620. He created the first book with sign language signals for teaching deaf people.