Introduction to 1-Naphthaleneacetic acid

1-Naphthaleneacetic acid (NAA) is a synthetic plant growth hormone compound with a structure that substitutes a carboxymethyl group for the 1-position of naphthalene. It is soluble in organic solvents and commonly used as a rooting powder or rooting agent in plant propagation. It is also used in plant tissue culture.

Figure 1 Characteristics of 1-Naphthaleneacetic acid

Properties

Pure 1-Naphthaleneacetic acid is a white odorless crystal, while industrial-grade NAA is yellow-brown. It has a melting point of 130°C and a relative molecular mass of 186.21. It is insoluble in water with a solubility of 240 mg/L at 20°C, but soluble in hot water and organic solvents such as acetone, ethyl acetate, benzene, ethanol, and chloroform. It is photosensitive, can form salts in the presence of alkalis, and the salts are soluble in water. It is stable at room temperature.

Functional Characteristics

1-Naphthaleneacetic acid is a plant growth regulator belonging to the auxin class. In addition to the basic functions of general growth hormones, it can promote adventitious root and root formation in plants. It is used to promote seed rooting, cutting rooting, and root formation in Solanaceae crops. It can promote rapid enlargement of fruits and tuberous roots, making it suitable for use as a swelling agent in vegetables and fruit trees. It can improve flowering and fruiting rates, prevent flower and fruit drop, and has anti-abscission properties. It not only increases yield and improves quality but also promotes vigorous growth and enhances crop resistance to drought, cold, waterlogging, diseases, salinity, and other stresses.

Precautions

(1) 1-Naphthaleneacetic acid is insoluble in cold water. It can be dissolved in a small amount of alcohol first and then diluted with water, or it can be mixed with a small amount of water to form a paste before adding the appropriate amount of water. Sodium bicarbonate (baking soda) should be added and stirred until completely dissolved.

(2) Excessive use of 1-Naphthaleneacetic acid on early-maturing apple varieties can cause flower and fruit thinning. A concentration of 40 mg/L can reduce yield, and high concentrations can cause deformities, leaf withering, and leaf drop. Concentrations above 50 mg/L can cause phytotoxicity in figs. Excessive use on watermelon and cantaloupe can also lead to phytotoxicity.

(3) Ingestion of 1-Naphthaleneacetic acid can cause poisoning and damage to the liver and kidneys. There is no specific antidote, so immediate medical attention should be sought if symptoms of poisoning occur.

What are the emergency handling methods for 1-Naphthaleneacetic acid?

1-Naphthaleneacetic acid is an organic compound that can be harmful to the body. Therefore, it is important to take proper protective measures when using it. It is also crucial to know the emergency handling methods for 1-Naphthaleneacetic acid.

1. Emergency handling of leaks

If a leak of 1-Naphthaleneacetic acid occurs, the contaminated area should be isolated and warning signs should be set up. Personnel handling the leak should wear protective masks and chemical protective clothing, and avoid direct contact with the leaked substance to prevent dust from spreading. Carefully collect the leaked substance and transfer it to a safe place if there is a large amount of leakage.

2. Protective measures

For respiratory protection, a respirator should be worn when the air exceeds the standard. In case of a large leak, a self-contained breathing apparatus should be used. For eye protection, chemical safety goggles should be worn. When working with 1-Naphthaleneacetic acid, appropriate protective clothing and chemical-resistant gloves should also be worn. Smoking, eating, and drinking should be strictly prohibited in the workplace, and thorough cleaning should be done after work completion.

3. First aid measures

If 1-Naphthaleneacetic acid comes into contact with the skin, contaminated clothing should be removed, and the affected area should be thoroughly washed with running water for at least 10 minutes. If inhaled, the person should be moved to a place with fresh air and ensure clear airways. Artificial respiration may be necessary if needed. If ingested, immediate rinsing of the mouth and drinking milk or egg whites is recommended. If vomiting occurs, the person should be placed in a lateral position to prevent aspiration and seek medical attention promptly.

In the above article, we have provided information on the emergency handling methods for 1-Naphthaleneacetic acid. It is important to understand the correct procedures when working with this hazardous substance.

Reference

[1] Watkins D A M. The effect of ultra-violet light on 1-naphthalene-acetic acid[J]. Phytochemistry, 1969, 8(6): 979-983.

[2] Fang T B, Xiao H, Zhao L X, et al. Magnetic ternary layered double hydroxides for efficient removal of 1-naphthalene acetic acid from waters: Adsorption behavior and mechanism[J]. Journal of Environmental Chemical Engineering, 2023, 11(2): 109490.